MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > Personal Build Histories > MechMates already cutting
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Wed 10 March 2010, 00:23
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Mod woke up and gave #115 - Sacramento CA USA

Hi everyone, longtime lurker, finally getting around to being serious about this. I'll be posting and updating a lot (I hope!) as this progresses.

So far, this is what I'm planning on doing...

5' x 10' (9' maybe?) cutting surface. Large enough to handle both the European style baltic birch sheets carried by my local wood supplier (5'x5') and full sheets of MDF and Plywood with some room to spare. That being my primary size consideration, I figure 5x10 is nice and even, but we'll see how materials end up laying out, for economic considerations, I may pull that size down a smidge if it'll keep things cheaper and/or more efficient in use of materials.

I'm going to start out with fixed Nema 34 motors, brand undetermined at this point, but I'm actually playing around with doing some casting, so I'll be ordering one set of pulleys, and then playing around with casting duplicates in aluminum (I have 5 or 6 old lawnmower motors that I've scavenged for free to melt down and experiment with) to upgrade both X and Y axis with the belt drives, with a 4:1 ratio. I'm not sold on the size of belt for said drives at this point, with the ongoing debate between XL and L belts still inconclusive.. (?) We'll see how it goes.

I'll probably do some fairly significant redesign of the Z axis, based off some other machines I've seen around, but I'm really not sure about that yet. I like the fairly straight-forward design of the Mechmate, and its obviously tried and tested, but I may play around with a leadscrew and linear bearings or something fun like that. That's kind of my big question right now, I may just scrap that plan and go totally Mechmate, or I may do both.

I'll be starting out running a 3 1/4hp Porter Cable Router, since I have 3 motors in my shop for them. (Don't even ask me how I accumulated three of the beasts. They just kind of show up...) But that will be upgraded to a spindle of at least equivalent power in the relatively near future once the machine is running and making money.

I'll be cutting and machining everything on my own. I'm very lucky to have a good friend with a waterjet and a pretty well stocked machine shop. With the exception of cutting the main beams, I think everything else will be done by me.

Also, planning on using the hardened steel rails attached to the aluminum structural angle, though if budget approves, supported linear bearings look veeeeery nice.

So, yeah, any questions or comments are greatly appreciated. Suggestions as well! :-)

Oh yeah, computer running it will be a 3.0Ghz processor, 8Gig Ram, most likely using Mach3. Should work out pretty well...
Reply With Quote
  #2  
Old Wed 10 March 2010, 00:32
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Also, thank you to everyone on this forum that has contributed your ideas, help, suggestions, etc. You guys are great.

And especially to Gerald, for his amazing work on this lovely machine. :-)

A little about myself... I'm 26 years old, started out college as an Aerospace Engineer, but decided that I really couldn't handle that much math, so I switched over to History and am working on finishing up my degree and teaching credential. I have probably entirely too much confidence in my ability to do anything I decide I want to, and that gets me in trouble all too often, but every so often, I really surprise myself. I'm hoping that the Mechmate goes into that category, not the 'perpetually unfinished projects' bin...

I do plan for this to be a production machine, doing, really, whatever anyone will pay me to do on it... Bills need to be paid. For my personal use, I'm leaning to build electric guitars, and I'm looking forward to doing some of that on the Mechmate. A friend of mine has requested that I build some good speaker boxes for him, and I have an ongoing commitment with some vendors who do Renaissance Faires and other similar events, to produce various small items in wood, and I'm really optimistic that the Mechmate will make that work substantially easier.

Really looking forward to getting started. Currently laying everything out so I have a firm pricetag to get my budget approved, and then if that goes well, I'll start some ordering...
Reply With Quote
  #3  
Old Wed 10 March 2010, 01:04
KenC
Just call me: Ken
 
Klang
Malaysia
Welcome Eric,
Your enthusiasm touched me, you sounded like someone I know when I was a lot younger

You have so many plans for this machine & a lot of good ideas to achieve it. BUT (Don't want to sound like an old air bag but this is what I learn over the years.) the first thing you got to decide is what EXACTLY, what you want to achieve & then plan what you do to accomplish the goal.

"I want to build a MechMate" is too general. Do you want to build as MM plan? if so just build as plan. Do you want to design something else? the go to CNCzone to find liked minded people & start the journey. Do you want to modify/upgrade MM? Then access yourself if you know enough to know what is there to improve? Then access your ability to carry out the mod/upgrade. Are you going to build at lowest possible cost? Max out the budget & indulge yourself with everything including the kitchen sink & gold plated toilet bowls? Minimum labor hours? Do everything by yourself?... etc etc..

BTW, I recon casting your own AL timing pulleys should be a different project all by itself; Chances are this may contribute the chance of your MM going onto your "perpetual unfinished projects' bin".

Hope this helps
Reply With Quote
  #4  
Old Wed 10 March 2010, 01:21
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
KenC,
Thanks for the advice! I definitely understand the need to focus, you probably do know me all too well. :-)

As for what I want to do, I'm definitely sold on the Mechmate's overall design. The only area that I'm even considering playing around with is the Z-axis, and even that, I'm very, very iffy on. I do have the mechanical aptitude to pull it off (I hope?), if I decide to go that direction, as I'd basically be lifting directly from another existing design and utilizing that.

Money is a much bigger consideration than time for me. I'll be doing the vast majority of the work myself, everywhere I can save money, I will be doing so, without compromising the quality of the machine. Thus why I'll be starting off with the direct drive Nema 34s, then upgrading to the belt reduction when I can. From what I've read, the improvement in quality is substantial, which I'm all for. :-)

The Al pulleys are going to be an upgrade, at this point. I'm going to start off with direct-drive to get things rolling, and then upgrade when I have the time to do so. If I get bogged down waiting for parts, or waiting for money, it'll be a good side venture to take up my time and continue towards my eventual goal.

Thanks for the suggestions, and especially the reminder to focus. I need that sometimes. :-)

Sometimes? Scratch that, ALWAYS.
Reply With Quote
  #5  
Old Wed 10 March 2010, 01:38
KenC
Just call me: Ken
 
Klang
Malaysia

Our plans are identical except for casting the timing pulleys.
Reply With Quote
  #6  
Old Wed 10 March 2010, 05:23
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
Welcome to the forum!!

The cool thing about the MM is you build it by the letter you can have a great working machine. You can also mod that Z later since it bolts right in and many have completed mods here for you to sample.
Reply With Quote
  #7  
Old Wed 10 March 2010, 07:39
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Welcome, Eric. Note that moving up from an 8' cutting capacity to a 10' one may cost a bit more. See more about this starting at post #36 in this thread
Reply With Quote
  #8  
Old Wed 10 March 2010, 12:12
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Hey Brad,
I looked over the thread you posted, it seems like they're talking more about cutting capacity below the Y gantry. I was talking about total length of the machine, 10 feet long. It'll depend largely on how long of a beam I can get to cut, if I have a lot of material waste, it obviously won't be worth it, and I'll stick to 8/9 feet of travel along the x-axis.
Or did I just not read far enough on the thread?
Reply With Quote
  #9  
Old Wed 10 March 2010, 12:13
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Thanks for the welcome, MetalHead. :-) I've actually been a member for like 2 years+ now, just finally getting around to seriously prepping to build one of these monsters. And I very well may do that, or have them set up back to back, with a router and spindle... Who knows? The possibilities are endless, that's why I love this design...
Reply With Quote
  #10  
Old Wed 10 March 2010, 13:26
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Eric, you've got it right; a standard 20' (+ a bit) will yield a machine of 122 X inches or so, which will cut 8' (or 97" MDF) with a large cutter and a little bit to spare.

If you go for larger, then you have to order two pieces of steel, cutting charges, etc.
Reply With Quote
  #11  
Old Sat 13 March 2010, 09:43
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Okay, so I have been sourcing steel suppliers, and the company I just called, unfortunately, does not have 3" x 7" c channel, the closest they have is 2 1/16"x7". Am I going to have issues with my main longitudinal beams being that narrow? I haven't found specific references to how this would be a problem on the dimensions yet, but since you guys have more experience with actually building these, I figured I'd throw the question out there for your feedback.
Reply With Quote
  #12  
Old Fri 19 March 2010, 10:06
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Okay, just want to run this by the people here to make sure I'm not crazy and/or missing something...

I'm planning on going with the Gecko 201x drives, they look really good, and seem to have plenty of power and some good safety features for those of us who are not so electrically inclined.

I'll be using MotionKing's 34HS9801 motors (here: http://www.motionking.com/show_produ...12&fenlei_ID=2 )

I'll be doing direct drive initially, but I have money budgeted to go up to a 4:1 or 5:1 belt reduction drive in the very near future. Are those motors going to be strong enough to handle the direct drive initially? Intuitively, I feel they are, but I wanted someone's opinion before I actually placed the order...

I also figure that the 201x drives will give me some expansion room should I choose to go to larger motors at some point in the future, and I won't be pushing their limits driving a 4A stepper.

Comments?
Reply With Quote
  #13  
Old Fri 19 March 2010, 10:27
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Have you looked at the extra features of the G203V? Might be worth your consideration.
Reply With Quote
  #14  
Old Fri 19 March 2010, 10:36
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
I have, and aside from the safety features (which ARE very attractive), I did not see a significant difference. Is there something I'm missing, performance-wise?
Reply With Quote
  #15  
Old Mon 22 March 2010, 05:48
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
I don't think the extra cost of the G203 is justified today.
Reply With Quote
  #16  
Old Mon 22 March 2010, 10:13
Codered741
Just call me: Cody
 
Lancaster (Pennsylvania)
United States of America
Belt drive max ratio

Hey eric,

I know that your are not doing the belt drives right now, but just be aware that it is not recommended to use belts for ratios higher than 4:1. At that ratio the small pulley does not have enough engagement.
And worse, if you use timing pulleys at that ratio, it can become choppy, because of the few number of teeth engaged in the belt.
Reply With Quote
  #17  
Old Mon 22 March 2010, 11:05
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
I've seen a number of comments about that, however, I'm not going to be using a smaller pulley to achieve the higher ratio, I'm going to be going to a larger one. Hopefully it'll give me plenty of engagement.
Reply With Quote
  #18  
Old Mon 22 March 2010, 11:50
Codered741
Just call me: Cody
 
Lancaster (Pennsylvania)
United States of America
In order to achieve a ratio, you need one large pulley and one smaller one. Regardless of arrangement of the pulleys, which one is driving the other, above a 4:1 the smaller of the two pulleys will not have enough engagement. The engagement of the larger pulley will of course be enough.
Reply With Quote
  #19  
Old Mon 22 March 2010, 12:23
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Quote:
Originally Posted by Codered741 View Post
In order to achieve a ratio, you need one large pulley and one smaller one. Regardless of arrangement of the pulleys, which one is driving the other, above a 4:1 the smaller of the two pulleys will not have enough engagement. The engagement of the larger pulley will of course be enough.

I assume that you're talking about the number of teeth engaged in the gear, and the concerns about it hopping out of the teeth, etc.? There are two ways I've seen of handling this problem that I think are pretty viable. One is using a tensioner, having a bearing or similar object that changes the angle at which the belt engages the smaller of the two gears, the other is increasing, if even marginally, the distance between the two gears. That, to me, is more problematic because of concerns of belt stretching, but still a possibility. Is there a particular reason why either option wouldn't work, beyond what I've mentioned?
Reply With Quote
  #20  
Old Mon 22 March 2010, 23:23
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
I had thought about this problem and the only solution I could think of was to use idlers on each side of the small pulley. The idlers could be used for tensioning the belt and making the belt wrap around the small pulley. The idler could be as small as 1/2" in dia but will need to ride on bearings.
Reply With Quote
  #21  
Old Tue 23 March 2010, 06:08
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
I would think you would need a step pulley setup to get a belt drive to 7:1

But the 4:1 stuff that I have seen looks really good in cut quality.
Attached Images
File Type: jpg Pulley Drive.jpg (15.7 KB, 1643 views)
Reply With Quote
  #22  
Old Tue 23 March 2010, 06:30
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
I like the double set of pulleys. It just makes the whole thing thicker and the motor sticks out further. If you use hubless pulleys and install the setscrews between the teeth of the pulleys it would get thinner. The pinion output shaft and motor shaft need to be offset.
Reply With Quote
  #23  
Old Tue 23 March 2010, 07:35
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
Here is a quick and dirty 9 to 1 drive. Needs belt tension method for second belt.
Attached Images
File Type: jpg 9 to 1 Belt Drive.JPG (17.0 KB, 1647 views)
File Type: jpg 9 to 1 Belt Drive 2.JPG (17.8 KB, 1649 views)
Reply With Quote
  #24  
Old Tue 23 March 2010, 07:46
KenC
Just call me: Ken
 
Klang
Malaysia
Is there any need for a 9:1 reduction in MM application?
Reply With Quote
  #25  
Old Tue 23 March 2010, 07:50
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
I already had 15 and 45 tooth pulleys to throw into a model. If they fit then pulleys for a 7:1 will fit. More of a concept than an actual.
Reply With Quote
  #26  
Old Tue 23 March 2010, 14:34
MetalHead
Just call me: Mike
 
Columbiana AL
United States of America
Yeah that's what I mean ....

I just can draw that purty
Reply With Quote
  #27  
Old Tue 23 March 2010, 14:36
Johannescnc
Just call me: John
 
Hannover, DE
Germany
Hey John, what did you use to draw these?
Reply With Quote
  #28  
Old Tue 23 March 2010, 15:21
Tokamak
Just call me: John #121
 
Monrovia (ca)
United States of America
Solidworks 9.0
Reply With Quote
  #29  
Old Sun 04 April 2010, 23:15
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Well, its finally here... I get the money on Tuesday, orders go out on Wednesday, and this thread will officially transition into the Building In Progress area....
Reply With Quote
  #30  
Old Sat 07 January 2012, 11:21
Zouave
Just call me: Eric #115
 
Sacramento, CA
United States of America
Hah, two years later...
My build is nearing completion, I will be posting some progress pics shortly, but am about 75% done with the mechanical side of things, now freaking out about the electrical...
One step at a time.
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:29.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.