Just getting started.. couple questions... [Archive]

Mountaincraft

Sun 18 July 2010, 18:20

Just getting started.... early planning stage

From the drawings, it appear s that the main longitudinal support beams are 8" x 3" C channel.. correct? How thick of steel?

I have a mile of 2" x 6" x 1/4" C channel I salvaged off of a mobile home frame.. Would that stuff be useful for anything in this project? I'm guessing that it would change everything in as far as the pre-made laser kit mike sells, so it shouldn't be used for the main rails, right? At least not if I plan on using that kit...

I am planning on making a dual use table (plasma/router), so I need to create some sort of system where the cross supports are farther down, allowing room for a bed of replaceable metal 'slats' to support the work... I also need to be able to place some 2 to 3 inch thick vacuum panels on top of the slats for when doing router work... either that or a single large hold down panel (probably 3/4 to 1.5 inches thick) meaning I'll be using up 5 or six inches of the available height of the main longitudinal supports... I guess I could modify the router mount to be higher, but that still probably only leaves me 2-4 inches of room for clearance over the work support surface when routing...

How have those of you that do the dual use thing solved the work surface issue?

I'm also wondering if the bracing network underneath the main support beams can be reduced in height a little.. I'm thinking it would be nice to place two or three 'catch basins' underneath the thing that could be emptied after routing, and then filled with a couple inches of water during plasma cutting... Maybe mounting some sheet metal screen panels on the inside of the base to contain sparks and slag...

Would like to hear how others have approached this dual use problem...

gooberdog

Mon 19 July 2010, 11:52

Hi Mark and welcome. You could certainly use the channel for the bed rails in place of the 3" channel spec'ed. There is a post about mating 2 pieces of smaller channel to make the main X rails. None of these would change the plans much. The original X rail is a 7x14.75 C channel (7 inches deep, 14.75 pounds per foot).

You should still be able to use the kit without any problems and I might suggest USE THE KIT.

Can't offer much on the dual use efforts. Sawdust does burn and plasmas are messy in their own way.

Can't wait to see your project progress.

MetalHead

Mon 19 July 2010, 14:00

My kit parts will work fine with your support channel choice. The kit it really the X, Y and Z parts of the mahine. So as long as you keep to the plan on those parts you can use a lot of the steel you aready have for the rest of the table.

Mountaincraft

Mon 19 July 2010, 14:40

Called my steel supplier.. and they said that 7 x 14.75lb is an odd size he'd never heard of... but that it would be just under a half inch thich steel.. Does this sound correct? If so, that's some seriously thick stuff!

The plans show a 14" rail as an option.. says it reduces accuracy.. HOw much? What is target accuracy with the 7 inch channel, and how much is it reduced with the 14?

I'm thinking about welding two sixes on top of each other, facing opposite directions... this would allow me to mount a small C channel on the inside of the bottom one to hold the plasma support slats...

Is the reduced thickness and the increased height of the dual six channel approach going to reduce accuracy much?

The six inch channel is 8.2lbs per foot... (16.4 lbs stacked)..

Man this is going to be a heavy beast!

Mountaincraft

Mon 19 July 2010, 14:45

Just wondering.. Is the reduced accuracy because of the taller support rail, or because of increased Z travel? Because if it's the latter, then my slat bed will likely bring the 'effective' rail depth to within an inch or so of the original rail depth...

MetalHead

Mon 19 July 2010, 21:35

OK Maybe I missed it above. What gauge thickeness is the channel? You could use this and make the side legs taller to compensate for the few inches needed to extend the Z travel.

So if you look at the finished height of the sides and take what you have... 6 inch material and compensate that difference (2 inches typically) with longer legs you should be ok on the build. You may loose some rigidity but I doubt it will be an issue.

Another option is called an expanded beam I believe. You would lose rigidity here. Basically you take a beam longer than needed. Cut half oposing hexigon shapes down the middle of the beam , seperate the two then off set each by the distance of the half hexegon and re weld. This yealds a 12 inch beam but can be adjusted to get the desired width beam. I am not sure about the name of this kind of beam.

If you have tons of channel, scrap it, use the money to buy what you need. Cleans up the yard also :D ...

Mountaincraft

Mon 19 July 2010, 22:26

Winter before last, when the economy hadn't fully hit yet, scrap steel was worth over 240 dollars a ton... Last winter, is was worth less than 20 dollars a ton... I had to 'pay' a scrapper to come and take the rest of the stuff (kept the channel).. It costs me $25-30 in gas to drive to town.. Would take three or four trips in my van to get the steel there.. I would spend 16 hours of time, and $120 in gas or more and have $40 to spend.. I don't work for the govt, so I can't put lipstick on that pig... LOL

The channel is 1/4" thick.. I have a couple ideas I'm tossing around, but things get lost when using words to describe them.. I'll put them together in 3D and post images to see what we've got going on here...

From your response, I take it that the issue is not the actual height of the support beams that causes accuracy issues, but rather the length of Z axis travel... This is a good thing IMO.. It means, that I can use the idea I'm considering, and will likely be OK... provided the channel is beefy enough...

But like I say, I'll post some images, and get some feedback then... Using words to describe this stuff is kind of prone to error and misunderstanding...

Thanks....

PS.. can you point me to some info where I can get understanding of the difference between the belt and gear drive.. From the pictures, videos, and drawings I've seen thus far, I was under the impression that the motor spindles were direct drive connected to the gear that is in contact with the rack....

domino11

Mon 19 July 2010, 22:33

Mark,
You can use direct drive motors with the pinion gear, regular stepper motors that drive belt reduction units that are then connected to the pinion gear, or self contained gear reduction stepper motors that are then connected to the pinion gear. Have a look at the build threads to see the choices made by others. :)

Mountaincraft

Tue 03 August 2010, 07:25

I finally got around to uploading some renders of what I'm talking about.. I didn't bother 'slanting' the ends of the rails, as it was not necessary for discussion purposes...

This is an end view without the support slats installed for plasma cutting.. I have colored each piece of steel differently for clarification purposes..You can see that the rail is built up from two 2x6 'C' channels facing opposite directions.. a 'notched' 1 x 2 channel is welded (or bolted to allow replacement) to the side to hold the vertical 'slats' that support the material for plasma cutting...more 2x6 'C' channels are used (with the ends notched to allow proper 'height' of the cutting bed) as horizontal cross supports for the longitudinal rails... In this configuration, the top of the slats are 7" below the top of the longitudinal rails...
http://www.r8rphan.com/mechmate/view-6.jpg

Here's the same view with the support slats installed
http://www.r8rphan.com/mechmate/view-7.jpg

And here are some more views of the idea
http://www.r8rphan.com/mechmate/view-1.jpg
http://www.r8rphan.com/mechmate/view-2.jpg
http://www.r8rphan.com/mechmate/view-3.jpg
http://www.r8rphan.com/mechmate/view-4.jpg
http://www.r8rphan.com/mechmate/view-5.jpg

And here is and end view of the scrap steel I am wanting to use
http://www.r8rphan.com/mechmate/steel-2.jpg

I'm hoping that this stuff would be 'beefy' enough for this use, as it would save me $600-800 right off the bat...

I am also considering the idea of adding a 1/4" x 12" steel plate to the bottom 2x6 'C' channel that would extend down 6 inches and be solid welded to the leg support system and the horizontal cross supports to add rigidity (length of the table bed).... IOW, welded to the purple 'C' channel to box it in and tie it solidly to the base legs, simultaneously adding 'bracing' the leg system...

What do you think? Would this be 'sturdy' enough? It's extra work, and the scrap steel needs a lot of prep/clean up, but I have more time and energy than I do money at the moment...

KenC

Tue 03 August 2010, 09:07

Mountaincraft

Tue 03 August 2010, 12:18

Why not meet half way, buy a "standard I-beam & use your 2x6 Channel for the cross table brace. Less work, less complex less welding (= lesser distortion). Guaranty a beefier table then the stock design.

There are two steel suppliers in town..... I priced out those two rails.. The cheaper of the two places if I went with a 2x8 channel, thinner steel than what is spec'd in the plans.. was $450 or so, and that's if they keep (buy back) the leftover steel (has to be bought in 40' lengths).. The spec'd channel would be special order, and considerably more expensive (more steel, plus special order)..

The cross braces are not the expensive part.. It's those rails... :eek:.

As far as welding goes, I figured I's skip weld it all... weld an inch, skip a foot, weld an inch, skip a foot, etc.. then come back later, and weld an inch half way in between the first set of welds, etc... eventually, I'd have a continuous weld... It'd be a pain, but should reduce distortion from heat, and I have two large rolls of welding wire already, plus what's on the existing reel in the welder now...

MetalHead

Tue 03 August 2010, 15:22

Go read this thread
http://www.mechmate.com/forums/showthread.php?p=35741&postcount=1

I think if you take some of these ideas and use longer legs you can get your base where you want it. The real particulars are from the X rails up. Those pieces of the gantry are more critical that the base. In the base you are looking for rigidity, but I think you can build a base from what you have and save your money for other stuff... Like a parts kit from me :D !!!

Just kidding about the parts set. Not kidding about the modified base !!

Mountaincraft

Tue 03 August 2010, 16:18

It is probably a good thing that I am short on money.... That means it will take me a long timer to build this thing, and as such, the likelihood of making mistakes will be reduced..

More time to learn! And after reading through that thread, I see I have much of it to do..... More than I thought....

The dual Z slide thing is interesting? I was just thinking that I would make some sort of 'replaceable mount' that goes on the Z slide.. with a custom mount for each type of tool needed.... Maybe heavy duty slide in clips on the bottom of the Z slide, and a bolt or two on the top...

And I 'definitely' am planning on the parts kit.. Seems like a no brainer to me on that issue.. But it will be a while... Perhaps there will be a motor and controller kit available by the time I need it too...

Mountaincraft

Tue 03 August 2010, 16:32

Hey Mike.. I garner from your comments earlier about using the 6 inch channel and longer legs, as well as the pictures in that thread of the torchmate where they used 2x3x1/4 tubing, that what I make the base out of, and the exact design is very flexible and not so critical, as it is for everything above it....

So perhaps I can rethink everything, and look at more options.... I have more than 200' of this 6 inch channel, so that will give me plenty of options.. I also have some schedule 40 2", some 1/2", 3/4", 1" and 1.5 inch square tube, 1inch, two inch, and 6 inch flat stock, 2" angle and so on...

I get the idea that I can get creative on this part of the build.. and fortunately, this is where most of the steel is used... The amount of steel I will need for the gantry and Y car is much less....

BTW, I would 'like' to make it big enough to handle 5x10 sheet stock... I imagine that doesn't change things regarding my ability to get creative so much as it just changes the amount of material needed for the base table...

As I am scrounging for and selecting steel, how long of pieces will I need to handle 10' material length? And how long will the crossmember pieces need to be to handle 5' material width? Not talking exact lengths here, just 'minimums' to select and prep before actually cutting to exact dimensions...

smreish

Tue 03 August 2010, 19:26

Mountaincraft

Wed 04 August 2010, 00:53

Mark,
Have you downloaded the drawing set's yet.....5 pdf downloads.
The drawings have a series of nomenclature that dictate the method.....saw, cut, weld, assemble, etc.

The first set of drawings show the lengths needed as X + dimension, and y + dimension respectfully, thus if you want a 10' cut area, you will need a member that is 10' plus (about 24") and 5' plus (~17" depending on member)

Again, download the plans and refer to Part 1 drawings for the base table steel raw lengths needed.

Good luck.

Sean

Hi Sean...

Yeah, I downloaded them weeks ago, and my printer is 'still' panting form the workload.. LOL

I know the info was on there.. I was being lazy.. and asking a 'general' question regarding rough stock length so that I didn't have to drag all the printed plans out and find out for myself.. After already wasting a bunch of time, paper, and ink printing them out in the wrong orientation, I do not want to even touch the correctly printed plans until I can get into town and simultaneously remember to buy a couple hundred plastic document sleeves for them... figuring that is actually cheaper than having to print them yet again... :D

Before I have to actually cut things to exact length, there's no doubt that I'll have to dig into things to a significant degree... For now, I was just looking for some "safe" general lengths to cut the channel to to start prepping it for the exact length...

I need much edjumakashiafying... So more stupid and obvious questions are certain to follow...:D

Gracias..
Mark

MetalHead

Wed 04 August 2010, 05:01

What you will find in this group is we all pretty much have the drawings memorized. Once you get there your questions get specific to things that are not in the drawing files and that is when you will get the best feedback on your build for the rest of the team.

We all know when someone asks a question if they need to study the drawings in more detail. But you are on the right track. Sounds like you have enough steel to build your base anyway.

Mountaincraft

Wed 04 August 2010, 07:17

Yeah, I know.. Before I actually start cutting things to exact length, I will be 'very' familiar with them.. I have gone through them a couple times...

I was looking for a more general answer though.. You know, "like I would look for pieces at least a couple feet longer than your material requirements", etc... But that's cool, I can figure it out... Mine will not be standard to the drawings anyways.. so ultimately, I will 'have to'...

The main thing I was interested in at this point, was finding out how much creative 'leeway' I have in the rails and table system, and if what I have already is usable for this purpose..

The 'torchmate' thread proves that there is a 'lot' of leeway, as their table base is radically different from the plans... Mainly, it just needs to be solid/stable and big enough to support the angle stock that the gantry rides on, and the material being cut..

From looking at the drawings, I am also under the impression that the table doesn't have to be 'that' perfectly square either, as the squaring gets dialed in when the angle stock is mounted.. that they are what are important to have as square as possible...

So a 'little' distortion from the welding, probably won't be a big deal, as long as the end result is a pair of level and square rails for the gantry to ride on..right?

Which brings up another question... What do you guys rely on for leveling? Framers levels? Or is something more precise (ie transit or laser level) required? Seeing as there is a need to get the rails set to the same height and level with each other, what techniques are recommended for this?

I was thinking of using scaffold leveling jacks for feet as they are rated for tens of thousands of pounds each, and are easy to adjust, as this would allow the easy change out to scaffold wheels when I want to move the unit... They fit nicely into inch and a quarter schedule forty pipe, which can be welded into beefier legs if needed..

That would take care of leveling the unit as a whole after the fact, but how precise should I be in regards to getting the rails leveled to each other? I have several framers levels, a couple water levels, small laser levels, etc.. but I'd have to buy or borrow a laser transit level if something of that accuracy is required.. Obviously, the material bed has to be pretty level to these rails as well...

Or are there other options I'm not considering? What has everyone else used? Or do they find that just using a tape measure and square is accurate enough, and don't even bother with levels until the base is complete?

Does the software do any sort of compensating for minor inconsistencies? I mean, does it allow calibrating of the material bed in relation to the work head? We are talking thousands of an inch cut accuracy, so I'm hoping the software allows calibrating the table itself.... if not, then the work bed being five thousands of an inch out of level in relation to the gantry rails in either direction could have a pretty big impact, no?

Thanks,
Mark

Mountaincraft

Wed 04 August 2010, 07:28

Has anyone ever incorporated a "material leveling" system into the MechMate? I was thinking, that if the material bed were attached to a couple sturdy rectangular tubes, they could be mounted to the main table base via large, fine threaded adjustments bolts.. This might be a way to achieve electrical isolation as well, to resolve the problem they had in the TorchMate thread...

Then I wouldn't have to notch the crossmember pieces either, as two inch x 1/4" square tubing would make up the height difference.... and then my lat system could mount on 'those'... the two inch tubing would then be attached to the table via leveling screws...

Is that a workable concept? Or am I not considering something?

smreish

Wed 04 August 2010, 11:19

Mark,
What issue are you referring to in the TorchMate thread? I don't recall us having any significant "bed-to-cutter" registration issues. (pretty familiar with the build since I was there :p )

And yes, we did go with rectangular tube for the build for the plasma machine. Our theatrical friends at the Seattle Rep made their true MM out of 2" square tube in a "trussed" arrangement to fit over their work tables in the middle of the shop. A lot of options......

***

Your mention of "leveling" table is possible, and some Shop botters have done this modification with a scissor lift as the table and had z level adjustment feet to level the internal work material to the cutter.

Overkill if your just routing daily since you surface the spoilboard to the cutter above.
Depending on your needs, it just might be added labor and expense for littler return value.

Good luck.

Sean

Mountaincraft

Wed 04 August 2010, 14:11

Hi Sean,

Mark,
What issue are you referring to in the TorchMate thread? I don't recall us having any significant "bed-to-cutter" registration issues. (pretty familiar with the build since I was there :p )

There was an issue with 'noise' from the plasma, interfering with the controls.. So they placed a piece of fiberglass matte in between the table and bed mounts, and used a non-conductive fiberglass bolt to reattach it..

Your mention of "leveling" table is possible, and some Shop botters have done this modification with a scissor lift as the table and had z level adjustment feet to level the internal work material to the cutter.

I would have no need of a 'scissor lift', but the leveling feet is along the lines of what I'm talking about.. what's a "shop botter?"

Overkill if your just routing daily since you surface the spoilboard to the cutter above.
Depending on your needs, it just might be added labor and expense for littler return value.

Okay, surfacing the worktable makes sense for routing... Now I understand the purposing of dropping the screw heads down below the bed surface...

But what about plasma?.. This is to be a dual use table... Probably will not change over from one to the other 'often', but I will likely be using it for both wood routing and plasma.. Also pondering ideas of how to plan for and deal with the issues of sawdust and sparks as well....

Initially, it will be used primarily for routing though...

So, how is leveling of the plasma bed (replaceable steel slats) best dealt with?... adjustment bolts on the slat support rails, or is their a better way?

Thanks,
Mark

DocTanner

Wed 04 August 2010, 15:21

The router-plasma table is a great concept............. I gave it a great deal of thought at one time. But there are many other things to consider. Placing a sheet of stain grade plywood on a machine where there has been nasty plasma dust doesn't work out so well. Exhaust venting, sawdust and sparks, etc.
Good luck with your build.
DonRoss

smreish

Wed 04 August 2010, 17:13

Don,
Great to hear from you sir #1 MM outside of the Gerald Camp!

The detail about the MM Plasma machine was to carefully build the table within a very close tolerance to maintain the datum plane for the plasma cutter to accurately maintain it's cutting arc. The Breakoutboard also adjust the z height of the cutter to maintain a constant cutting height regardless of the table height.

The fiberglass (which is a grounding isolation issue) was always planned if we had control issues. It just happens that we chose to announce it in the spirit of research and learning.

The gantry height of the machine was actually recalculated to allow all the uses of the machine. I believe the final height above cutting deck is about 12-14 inches of clearance. Far more than the 8" the design calls for. A separate removable spoil board can be placed ONTOP of the metal finger grid for wood or alum routing. This is held on with J-bolts or 4 small G/C clamps - then surface for use in router mode.

The dust collection and spark arresting is a 3rd party attachment in the shop the machine lives in and incorporates a spark blanket, high velocity and volume removal of the toxic environment. The entire machine is portable and base was designed to be lifted by pallet jack / fork lift.

If you are truly interested in the specifics of the UNCSA build, you can start with the YOUtube videos published for visual reference and feel free to contact any of the students or me via the forum.

Sean

Mountaincraft

Thu 05 August 2010, 08:06

Don,

The gantry height of the machine was actually recalculated to allow all the uses of the machine. I believe the final height above cutting deck is about 12-14 inches of clearance. Far more than the 8" the design calls for.
Sean

Hi Sean,

So does this mean that with all this extra clearance, you deviated from the plans on the range of motion on the Z slide? Or was this simply for clearance due to the increased bed height with the support grid and all? IOW, did you build this thing so that the Z slide actually traveled 12-14"?

In general, I am definitely interested in your build, as you have already gone before me on this dual use design...

Priced out 2x3 tubing yesterday.. Much cheaper... and I can probably buy remnants by the foot depending on what's available at the time...

smreish

Thu 05 August 2010, 09:10

bed height, torch height spindle travel, torch travel...all consideration.

The long version the the z slide in the plans allows for 11 to 14" of travel. This was maintained in the build.

Sean

KenC

Fri 06 August 2010, 03:51

Mark, Like you, I tinker with myriad of ideas before I started my built. Thousand & 1 questions sprung up while studying the stock plan... everything is suspicious...
My 2 cent worth for you is, Don't cut anything until the very moment you need them. You may want to change your mind...

Mountaincraft

Tue 17 August 2010, 07:41

Been off doing some research/thinking.... Leaning towards two separate builds, semi-simultaneously... the first a solsylva router build that will incorporate some mechmate concepts.. this first build will be primarily for 'learning'.. and for getting 'something' up and running in the short term.. the second, will be a mechmate targeted primarily at plasma... I plan to build the solsylva table as a 2' x 8', then start upgrading it, eventually ending up with a 4x8 or 5x9 table based in steel, with rack and pinion on the x and Y axis, and leadscrew on the z axis... with the ultimate goal of possibly using linear bearing slides for all axis (as an upgrade later on)...

So, a couple questions.. mainly targeted at the school project builders... Seeing as the table will be used primarily for plasma, I can assume that movement forces will not be as big an issue, seeing as there is no router involved, correct?...

If so, then the mechmate rails could be made using lighter weight steel? I'm thinking of starting the solslva table by building mechmate side rail/leg assemblies out of steel, that can later be used for the mechmate by welding in crossmembers...

I'm thinking of using 2 x 6 x 18" rectangular steel tubing (10' long) for the rails, and using the same material for the legs, welding two to each rail... then welding 1/8 or 3/16 C channel on the legs for the bed support, and then some angle farther down for shelf support (added rigidity)... I can get all the steel I need for these two table sides for around $200...

If I drill the pipe rail supports for the solslyva build in the same locations that are needed for the mechmate rails later on, then I should be able to use these same rectangular rail/leg assemblies for the mechmate table with minimal modification...

The idea here is to get something up and running, get an education to use in the final build, try some ideas out in the process of upgrading, and even have a router table to use to help build jigs and what not for the mechmate build...

Will probably get good drivers that can be used later, and cheaper motors that can be used now, upgrading to better ones later for the mechmate and the router tables...

Seeing as the mechmate build will require an investment of 7-10K or more, and a good 2-3 years, the $1000-1500 option of building a fairly decent quality router table based on the solsylva plans is attractive.. I can then have something running and perhaps turning out some product in 6 months or so...

Thoughts?.. Would the lighter weight rectangular tubing be sturdy enough for plasma (and light milling/routing)? I mean I use the same stuff to support a 12' x 28' foot portable stage, and that has to support several thousand pounds of equipment, stage surface, and people, and it doesn't even break a sweat...

Thanks,
Mark

Mountaincraft

Wed 18 August 2010, 07:15

In looking at both sets of plans, I think I've figured out a way to build my MechMate X table sides, with welded legs, X rails, and stops.. then modifying the solsylva wooden gantry to use the MechMate rollers......

I could then be using the table while I build a mechmate router table, and get all the parts together for the rest of the MechMate plasma..

Couple questions..

I'm beginning to think that the entire reason that the longitudinal rails are spec'd with such heavy steel is to provide enough meat for drilling and tapping of the rail... If so, then the idea of using 1/8" thick longitudinal rails, would require the drilling of access holes and using nuts on the back side... In which case, I could go with 2" x 2" x 1/4" tubing for about the same price, which is what the student build used... Am I correct in this thinking?

If I were to go this route, where is everybody buying the v wheels and bearings? And what can I expect to pay for them?

The Solsylva plans have the X rack mounted in a separate flat stock (wood) which is mounted to the side of the longitudinal rails.. This means that I'd have to remount the rack later to the longitudinal beams for the MechMate gantry, and am ready to convert the table over... The MechMate plans call for a 15mm x 15 mm rack, (5/8"?)... The solsylva plans call out a 1/2" rack... From this, I'm pretty sure that I can use the same rack for both builds..

So where do I buy the racks (and pinions) and what do I expect to pay for those as well?

Also, the mechmate plans show an option of using aluminum for the v rail.. What are the pros and cons of using steel over aluminum, and vis versa?

And a question for Tom.. If I were to buy the grinder kit from you now, is it possible to buy the laser cut kit later 'minus the grinder parts'?

I also have the option of just building the whole solsylva thing out of wood now and using it while I build the MechMate table... But there is more redundancy this way, and the more steel I use now, the better the accuracy/resolution is in my mind...

I also have a question regarding table size in general (these is the type of concptual question I hope to have a handle on through building the cheapo solsylva table before I invest loads of time and money into the MechMate)..

how hard is it to cut longer parts in a shorter table? How is this handled? I don't understand zeroing a workpiece or alignment or whatever at all. at this point.. And probably wont until I start actually using a table..

So how hard is it to route or cut a piece that is 7' long on a 4' table? Is this done all the time, or is it an exercise in frustration? I ask this, in that in case I decide to build the solsylva all wood true to their plans, I might just build a smaller table than the planned 2' x 8'... seeing as it's a temporary solution anyways..

Sorry for being all over the map here...
Thanks,
Mark

Mountaincraft

Wed 18 August 2010, 08:04

Found some hepco size 3 wheels from a UK supplier.. But the price is about $30 each? Without bearings? Is this right? Oh my gosh! Is there a cheaper way?

Also found racks and pinions at McMaster Carr, and even for the cheapo solsylva table I'm looking at $250! and that's just for the racks! add another $75 or so for pinions! Surely, there must be more affordable suppliers/solutions....

No matter which direction I go, I'll definitely be buying sizes spec'd for the MechMate and finding a way to 'make them work' on the solsylva.. No way I'm buying this stuff 'twice'

So far that means racks/pinions, and gecko drivers are to be sized for the MechMate.. Might as well figure power supply in there too... possibly steppers... At least I'll have all that stuff, (and likely the X table sides as well) out of the way for when I build the MechMate...

Then there's the cost of the torch and machine head on the plasma build ($2500 and up)... Wonder if I'll finish all this before I die?

Leaning towards an all wood solsylva, using racks/pinions, steppers, drivers, and power supply targeted for the MechMate...

Mountaincraft

Wed 18 August 2010, 08:38

By the time shipping and what not are figured in, $400-500 just to buy the v wheels and bearings for the MechMate, I might as well use the cheapo solsylva rail method, which makes the steel table sides pointless at this time.. Unless there's a cheaper way to get the wheels now...

Please tell me there is....

Gerald D

Wed 18 August 2010, 09:18

Mountaincraft

Wed 18 August 2010, 10:05

Source for Complete V-Roller bearing sets (with eccentrics) @ $good-price$ (http://www.mechmate.com/forums/showthread.php?t=18)

or

Make your own V-Rollers if too expensive in your country (http://www.mechmate.com/forums/showthread.php?t=20)

Hi Gerald,
Thanks, that helps some.. I don't have the means to make my own, but the other link you posted is a step in the right direction.. Does his wheel/eccentric sets include bearings?

Can you answer my question about how long pieces are cut in machines with too short of an X travel for the work? I'm curious how this is done.. I assume it can be, as I have seen people use CNC routers to cut guitar bodies, so they must have a way of realigning the work piece when turned over to do the other side...

Thanks again,
Mark

Mountaincraft

Wed 18 August 2010, 10:34

NEMA numbers as they regard to steppers, refer to a standardized bolt hole pattern correct?

What NEMA stepper number is the MechMate spec'd to?

Thanks,
Mark

PEU

Wed 18 August 2010, 10:38

nema 34

Mountaincraft

Wed 18 August 2010, 10:44

Thanks,
I didn't see it anywhere on the plans, but might have missed it if it's there...
Mark

PEU

Wed 18 August 2010, 11:26

there is a whole subforum about motors: http://www.mechmate.com/forums/forumdisplay.php?f=26 :) :)

Mountaincraft

Wed 18 August 2010, 15:42

there is a whole subforum about motors: http://www.mechmate.com/forums/forumdisplay.php?f=26 :) :)

Yeah I know.. and I'll visit it soon when it comes time to actually get into the nitty gritty.. Especially seeing as it appears I'll be buying a lot of things for my MechMate build out of order (ie motors and electronics before the base is even built)... I just didn't see the point in starting a new thread and rehashing everything I've already said here in another forum to answer a quick question......

But point taken...:)

Thanks,
Mark

Mountaincraft

Wed 18 August 2010, 15:54

My current thoughts are considering the idea of building the complete steel frame for the mechmate base (using 2x2 square tubing as in the student build) and then just bolting some nice straight hem fir 2 x 8s to the inside of the longitudinal rails, and then building the solsylva router system on that, modifying it to use drivers, steppers, racks/pinions, and power supply sized for the final mechmate build.. That will even allow me to go ahead and mount the mechmate rails and stop blocks and what not while the solsylva unit is still in use.. I can also fashion the flexible cable trays and all that on the solsylva build with the mechmate in mind.. I would then be able to build the gantry and Z carriage off the table while using the solsylva build.. Down time for the transistion should be minimal, as well as wasted parts....

Still sorting out the plan of attack, but this approach is starting to make the most sense...

And yet another 'totally unique' mechmate build will be chronicled on this forum.. Sort of like a butterfly.. metamorphing from a clumsy solsylva caterpiller to a beautiful mechmate monarch.... :)

$240 worth of 2x2 square tube (3pcs x 20'), a new tank of gas for the welder, and I'm off like a turd of herdles...

Scott Hightower

Sat 21 August 2010, 09:54

Just a thought on the slats for your plasma table.

On my cutting table we use thin slats and place them in alternating cradles when we install them. This forms somewhat of an "S" shape when looking at the slat from above. The bend in the slat improves the rigidity. Over the long haul you will save a ton of money in slat replacement.

Scott

smreish

Sat 21 August 2010, 13:49

Mountaincraft

Sun 22 August 2010, 06:03

Mountaincraft

Sun 22 August 2010, 06:21

Mark,
The students at UNCSA came up with a great slat table solution. Small sections of 2" c channel welded ontop of the cross bearers that allow for 18 ga strips to be placed between. This allows for any one slat to be replaced as needed.

Sean

Did you see my 3D mockups above? Sounds like a similar design to what I showed... But again, perhaps a picture would prove otherwise... I'm not really underatanding the difference at this point..

On another note, I was culling through all that 6" C channel I have yesterday... And I grabbed a 15' long piece and picked up one end, I was surprised how much it flexed under it's own weight.. I now understand the reason that such heavy steel is called out in the plans.. Granted, it was oriented 90 degrees from what it would be when used (the C was pointing up), but still....

At this point, I'm really leaning towards waiting and getting some heavy rectangular tubing.. 2x3 x1/4 or better....

So far, my plan is to build a base table that will handle 4x10 stock to eventually be the base table for a MechMate plasma.. Then bolt 2x8 hem fir facia to the inside of the rails and build a solsylva router system on top of them, but modified to use the steppers, controllers, and power supply for the MechMate...

Use the solsylva router to start producing product, as well as cutting precision plywood jigs for welding up the MechMate gantry... Then start building the MechMate router table (4 x 8), eventually using the steppers, rack, and pinion, etc. out of the solsylva gantry in the router table...

Question about the UNCSA build... you guys used a second Z slide foor the purpose of engraving and drilling... What would be required to do 'milling' with this second Z slide? Can 'water' be used as a coolant for cutting or does it have to be oil? The reason I'm asking, is because if water can be used, then that makes things easy with a water bath under the slat bed, which can be used for both plasma cutting and milling?

What kind of cutter motor would be required for milling, and if water can not be used but cutting oil is instead required, what kind of methods can be used for this without major hassle?

I'm asking all this so that I can decide what options I want to plan for in the base table before I build, should I decide down the road to include such features into it...

I'm obviously going to be at this for a 'long' time..... gonna try and get it right...

Thanks,
Mark

smreish

Sun 22 August 2010, 14:14

Milling is limited to aluminum sheet stock. Cut dry or lightly atomized water borne coolant with the appropriate onsrud bit.

Plasma spark were arrested via a spark blanket below slotted table and special dust collection for welding at end of table and high CFM overhead hood/vent for vapor.

If your going to use tube, I would suggest 2x2 and 2x4, 2x4 is required for the gantry, so it's a required purchase.

Sean

Mountaincraft

Thu 26 August 2010, 15:39

On Plan Page 10 10 300 W, it says that the dimension from outside edge of the longitudinal X beam to the outside edge of the opposite longitudinal X beam is to be Y + 17"... I was under the assumption that the plans were drawn showing a 4' x 8' table... 48" + 17"= 65"... Yet, on plan page 10 10 123 D, it lists the dimension of the support board as 1830mm (73.2").. Which is wider than the Y + 17" number specified on Plan Page 10 10 300 W... To make things a little more confusing (to me), Plan Page 10 10 300 D, shows exposed cross support beams on each side of the support board, making me think that it's actually 10-12" wider than the support board, meaning 85" or so.. considerably more than the Y + 17" formula..

Can someone please tell me what I'm misunderstanding here?.. I'm trying to get an exact dimension from outside of X beam to outside of X beam..

On a related note, does the Y + 17" number include a couple extra inches beyond the 48", or do I need to add that in as well?

I am shooting for a table to handle 4' x 10' sheet material....

BTW, since the support board is considerably larger than a 48 x 96 (or even a 5' x 9') sheet of MDF, how do most people orient the 'pieces' to make up the large support board bed?.. I'm guessing 3-4 pieces, 73" x "as needed" to hit the cross beams?

Thanks much,
Mark

smreish

Thu 26 August 2010, 16:24

Mark
The quick answer before I get to my printed plans is it's okay, I'll try to explain. First, the MM#1 which the plans are based on were designed for the EU / SA standard board sizes which are in Meters....thus not even close to a US standard. The plans, depending on the detail, don't necessarily refer to one machine build, but a "style of building" for many options of the machine. Thus, different spoil board sizes, z stroke, rail type, etc. If your spoil board is to cut is 4' x 10', then the hole layout you choose will be EQ spacing based on that size - discard what you see in the MM plans for hole-to-hole measurements. Just adhere to the spacing minimums as a guide.

1) the plans allow for run off area around perimeter of the cutting area. Thus, is your machine is designed to cut 4' x 10', NET, then your actually cutting area will be about 52" x 124" gross. This is to accommodate large diameter cutters.
2) The x dimension from outside of x to outside of x is handled in the y+17 formula. The cross bearers that connect the C channel are actually SMALLER to allow for welding to the main long beams. IF your building a bolt together table make sure you pay attention to the set back requirement or you will be to narrow. DETAIL on 10 10 302
3) If your making a 48 x 120 cutting area, then you should be able to get a piece of MDF easily that is 5' x 10' x 1" (which is normal) or get 3 sheets of 4' x 8' x 3/4" and stagger the seams and laminate the layers together.

Hope this helps.

Sean

Mountaincraft

Thu 26 August 2010, 17:09

Okay Sean, that does help....

So the Y dimension I want is 65" outside of beam to outside of beam, and this is inclusive of 4" 'extra'? And the X dimension length length of each longitudinal beam is 120" + 24" (600mm) or 144" (12')?

A couple questions in regards to 'your' build..

1) You used 2"x4" x 1/4" rectangular steel tube, right? Did you 'drill and tap' your V rail attachment bolts into the 1/4" rectangular tubing, or did you drill access holes and use nuts to back up the mounting bolts?

2) If you were building the table for 'plasma' only, (ie no second Z slide for milling/drilling/routing), would you have built the table so heavy duty, or would you have felt comfortable using lighter or smaller or less steel?

3) Did you guys mount a router motor to that second slide, or a spindle? What HP?

Thanks,
Mark

Mountaincraft

Thu 26 August 2010, 17:15

Oh, and before I forget..

4) what size material support slats did you use? How tall, and what gauge?

Thanks,
Mark

KenC

Fri 27 August 2010, 02:59

1) its in the plan.
2) season to your taste
3) you are only limited by your imagination
4) is in the plan & also season to taste.
;)
Read x read x read = more reading

Mountaincraft

Fri 27 August 2010, 06:32

Hi Ken,

1) its in the plan.
2) season to your taste
3) you are only limited by your imagination
4) is in the plan & also season to taste.
;)

1) Actually it's not... The plan calls out for 7" C channel, 1/2 inch thick.. Seans build used 2x4 quarter inch thick rectangular tube.. I would be hard pressed to find out how 'Sean' and the class mounted the V rails to their rectangular tubing by looking to the plans detail of mounting the rails to C channel.. would I not.. Maybe 'your' plans magically update themselves to reflect the modifications Seans class made during their build.. But I don't have such 'magic plans'...:D

2)I plan to, but I was asking how Sean and the other students "seasoned to 'their' taste"..

3) Well, actually, I am also limited by money, time, energy, and the laws of physics, and at the moment information and the ignorance that lack thereof creates......

4)This is incorrect.. Nowhere in the plans are replaceable support slats dealt with.. Nor even the subject of a plasma table breached.. The plans deal solely with a Router table with an MDF support board... not replaceable steel slats turned on edge... If I were to 'only' look to the plans, and then mounted a torch on the beast, I would then find I had a $10K BBQ on my hands... That is before the plasma torch cut through the cross supports and the whole table imploded...

Read x read x read = more reading

You have no idea how much I am doing just that.... :)

Earlier, Sean offered to answer any questions I had about 'their' build.. and so I was taking him up on that... If he had already answered these questions somewhere else, I will happily go there and read them, but at this time, I do not know where they are located...

Thanks Ken ,:)
Mark

smreish

Fri 27 August 2010, 10:49

Mark,
- 2x4 tube 3/16 or 1/4" wall - tapped all the holes. 5/16 UNC
- IF table was for plasma only would I make it so heavy? No, I would have used 2x2 sq tube 11 or 14 gauge and then used the "clamp strip" as in the plans for rail attachment for the x and y axis
- NOTE: heavy was also because the table moves around A LOT. Thus stiff enough to be moved via pallet jack or forklift. WE wanted to maintain stiffness as well.
- router on second axis Porter Cable 690 1.75HP
- Slats (this if from memory, but Cody set this up with 2" strips of 18gauge) It's close to that ....Can't honestly recall. Hopefully Cody or Jon and watching the forum)

Sean

Mountaincraft

Fri 27 August 2010, 16:48

Mark,
- IF table was for plasma only would I make it so heavy? No, I would have used 2x2 sq tube 11 or 14 gauge and then used the "clamp strip" as in the plans for rail attachment for the x and y axis

You might have just saved me a 'ton' of money (and labor)... thanks!

- NOTE: heavy was also because the table moves around A LOT. Thus stiff enough to be moved via pallet jack or forklift. WE wanted to maintain stiffness as well.

If you didn't have to move it around, but still used the router, would you still have built it as heavy? Or would you have gone with the lighter guage 2x2, or something in between?

- router on second axis Porter Cable 690 1.75HP

That's just a standard contractors router.. I have three or four of those laying around...

I have another question, what size steppers did you use?

Thanks Sean, you're already making life easier for me...
Mark

smreish

Fri 27 August 2010, 19:46

Mountaincraft

Thu 02 September 2010, 08:19

Om pk 296-7.2 for gantries. Z slides are kehling direct drive with 20t pinions

If using router all the time i would at least us 11 ga and stiffen the heck out of the spoil board and leg/frame area
To act more like a truss than a beam.

Look at brians build at the seattle rep. You see my point. He did a fine job of exactly this.
At this point, I've decided to make the solsylva thing a totally separate build, and to build a mechmate dual purpose table based on the UNCSA mechmate... And then sometime down the road to build a monster sized Mechmaste router only table..

So I actually made my first 'purchase' yesterday towards the mechmate, as small as it is.. A couple hundred document protector sleeves and a notebook to put the mechmate plans in, so that I can take it with me to the metal supplier, fabricators, where necessary, etc. A teeny weeny step down the path..

I'm thinking of using 2x3 or 2x4 rectangular steel tubing for the main rails (1/4" thick), and 2x2 square tube (1/4" thinck) for the material bed, the rail supports, and what not.. Planning on building a large 'U' out of the 1/4" stuff and then supporting it all with 2x3 and 2x2 3/16" tubing...

The 2x4 makes more sense in that I'd already have the main rails for the gantry with the leftovers, but it also means a much heftier initial purchase, so I may use the 2x3, which would give me some great leftover pieces to make the table legs..

I'll mock up a 3D version before I buy and start cutting, but I'm hoping to buy one or both pieces for the rail after the first of Oct, maybe sooner..

For the solslyva, I'm going to largely just use scrap wood I have laying around, and not put a lot of time and effort into it, seeing as it is to just be temporary.. I plan to modify it to use the larger NEMA 34 steppers that will ultimately be used on this first mechmate.. but otherwise, just go as cheap as possible on it...

I want one of these mechmate bad babies... in the worst way... LOL

First order of business is to start cleaning out the shop to make room for it...