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View Full Version : Ladies and Gentlemen we have steel! Melbourne,Australia


chunkychips
Thu 19 August 2010, 18:57
Hi everybody.

After much lurking and reading I have finally decided to take the plunge and build my own MechMate.

I have been enamored by cnc and the capability it presents to the perpetual tinkerer for many years. Consequently, I have spent many hours over the last couple of years reading everything I could find on the web.

I actually came across the MM site early on in my research but was frightened off by all the metal and the $$. I needed a cheaper option and so I focused on mdf based machines. Wood is cheaper and less scary :)

Late last year I took the plunge and built my first mdf cnc machine. A relatively small machine with a cutting area of ~700x700mm. For a hand made machine that uses skate bearings, althread drive screws and generally cheap bits and pieces it works surprisingly well.

However it does have problems.
- It's slow. I can only run it at max ~500-600 mm/min (not inches/min) before it starts to lose steps.
- Although impressively rigid it still has some flex at the router bit.
- It has backlash problems which are mainly evident when trying to drill small holes.
- At 700x700mm it is way too small (for my ego) :p

This was a fantastic experience but I did it without any direct support and made many mistakes. Still I learned a LOT.

One of the most important lessons I learned was that the most expensive part of the machine is not the structure, but the electronics and the linear drive system. Unfortunately any decent set of motors, bearings and rails required to run the larger machine I want are going to cost money. The saving is not going to be made by using MDF! In fact the few dollars saved here will only compromise rigidity, which defeats the purpose of spending money on the rest of the bits.

Initially I spent a few weeks trying to design my own steel machine. I quickly realised how much work that is and any mistakes here were going to be expensive and (with the weight of steel) possibly dangerous.

So here I am about 2 years later back at the MM site. This solution looks very reasonable now that I have spent (wasted?) countless hours and money doing it the hard way. Though I have no regrets because of what was learned, it's time to stop mucking around with toys and build a REAL machine.

I hope you will all be patient with me as I pick your brains on the various issues that are bound to arise.

I have been watching some of the local builds with particular interest as I am currently trying get my list of materials together and source them. I hope some of the Melbourne guys will be able to help me with some good local sources when I get to ordering local materials.

I promise I will read first before asking for hand outs.:)

As a final note I just want to thank everybody in advance (especially Gerald) for this fantastic resource. I look forward to my own serial number soon (what are we up to now?)

There ... it's done... I've introduced myself publicly ..... now I'm committed :)

smreish
Thu 19 August 2010, 19:02
Nick
Welcome to the pool. Come on in...the water is fine!

We're gentle - really.

Ask questions when your stumped, ask questions if your not....

Good luck,
Sean

chunkychips
Thu 19 August 2010, 19:46
Thanks Sean
Excited to be on board.

Ask questions when your stumped, ask questions if your not....


That's inviting trouble you realise. To paraphrase the great Bart Simpson..."What I don't know could fill a warehouse"

You may have to quit your day job ;)

Nick

Red_boards
Thu 19 August 2010, 19:57
Hi Nick,
Nice to see another build in Melbourne. Now we are 3. Plus 2 in Geelong. We can start investigating "bulk" orders for a few things (I have my electronics and steel, but am still shopping for racks, pinions, springs, Z-plate and a couple of the custom parts).

Contact Rick Nixon about the laser cut parts (he had extra sets cut when he built his machine) and to see his well built and functioning machine.

I paid around $1200 for steel from Moorabbin Steel for steel for an "overbuilt" 1200x2800 table with 350Z option (the BIG 300x95 beams were a bit more $ than the smaller ones) and this was a pretty good price when I compared a few quotes. More importantly the steel arrived and it was cut right and looks straight.

I've been shopping for 2 months now and it ain't over yet. Luckily I have full support from the minister for finances!
Good luck
Red

domino11
Thu 19 August 2010, 20:35
Welcome Nick! :)

AuS MaDDoG
Fri 20 August 2010, 03:37
Welcome Nick !!

Sing out if you have any questions mate!! good luck with the build.

Cheers
Tony.

riesvantwisk
Fri 20 August 2010, 05:37
Welcome to the club Nick! You won't regret it, the MM is a wonderful machine.

Looking at your past experience, the MM build would be relatively easy for you, and you have some people over there to go to...

good luck with the build, keep us posted!

chunkychips
Fri 20 August 2010, 18:03
Thanks guys. With such a great reception, I might just have to stick around :)

I have to say that, looking through the various threads here I am gobsmacked at the high quality of your builds. I clearly have a lot of learning to do when it comes to working with steel. Hope I can achieve similar results with your guidance.

My background is in software development. I have always been confident with wood as we did woodwork in secondary school, but steel is a whole other science.

A couple of years ago I took a weekend course in welding (stick). This gave me the confidence to consider steel for future projects.

Soon after that I bought a small (cheap) arc welder (see here) (http://www.ozito.com.au/productinfo.aspx?prodid=AWG-964). Figured I would only ever do small square tube stuff.

The question I have is will this be big enough to handle all the welding I need to do for some of the monster steel in this project. If not I may have to get a 15Amp power point and a bigger welder (more $$:()

I noticed Tony had to call in the big guns for some of his welding. Yikes!

chunkychips
Fri 20 August 2010, 18:16
Hi Nick,
Nice to see another build in Melbourne. Now we are 3. Plus 2 in Geelong. We can start investigating "bulk" orders for a few things...


Good idea Red. You are way ahead of me with your build but let me know if you are going to order something.

BTW I noticed you live very close to me. I am in Bentleigh. This could serve us both well.

Contact Rick Nixon about the laser cut parts ...

Thanks...will do

I paid around $1200 for steel from Moorabbin Steel ...

I have dealt with Moorabbin Steel the couple of times I bought any. I am glad you recommend them as I have been very happy with their service (and patience!)

I also use Cost Less Nuts and Bolts (in Moorabbin) for any fixings. Also very helpful and well priced.

tarlo
Mon 06 September 2010, 01:57
I too have dealt with Moorabbin steel on other projects, and have been very happy with their service and quality of work. I too live in Melbourne and will be looking at taking the leap into building a mechmate (or very similar) so if your looking into bulk ordering parts/components and saving on shipping, let me know.

chunkychips
Mon 13 September 2010, 17:44
PM sent to Tarlo

chunkychips
Mon 13 September 2010, 18:19
Update.

I have finally decided that the right size table to build is a 1220x2440. That took a lot of measuring and remeasuring of garage space (and a subsequent clean out ;))

After a bit (meaning a LOT) more reading I have come up with a design that allows me to better utilise the space under the table for storing long materials and sheets. This is a hybrid of a few ideas I have seen on the forum.

I was hoping that the structural engineers amongst you might cast an eye over it an let me know if this is likely to stand up to normal MM abuse. I am about to order steel and would hate to get it wrong at this early stage.

Some explanantions (all in millimeters):

1. Main x beams (dark blue) are 200x75 channel
2. Legs (red) are 75x75x3 box
3. Leg supports (green) are 50x50x3 box
4. Table surface supports (yellowish) are 75x40 channel
6. The two blue supports at the far end are for an indexer (some day)
7. I have added two little legs (green) to the bottom frame to provide additional support (ie prevent bowing) under the weight of sheet stock. This helps keep the sheet stock flat. Do I need these?
8. All legs will have leveling feet
9. Though I haven't drawn them, I intend to add wheels like Tony's here (http://www.mechmate.com/forums/showthread.php?p=45129&postcount=249). This may mean I bring the bottom frame down further to avoid having to use extension rods like he did.
10. All welded

My main concern is that I have deviated from the original brace design and was wondering if I am significantly weakening the structure in some way.

Thanks in advance for any help :)

domino11
Tue 14 September 2010, 16:30
I think you would want those braces to come right down into the corner and then extend at a true 45 Deg for the best result.

chunkychips
Tue 14 September 2010, 18:01
Thanks Heath

I agree that the longer bracing is better...BUT...what I am hoping to achieve is a good middle ground solution that allows for more wide sheet storage (upwards as well as across) and general access under the table without sacrificing table stability.

Scot mentioned here (http://www.mechmate.com/forums/showthread.php?p=45706&postcount=71) that he has no stability issues with his table and he uses no bracing. So I figured if I use "some" bracing I could get the best of both worlds.

He does use thicker steel though. Maybe if I go 4mm instead?

smreish
Wed 15 September 2010, 04:16
Build it like you need it and if you have an issue - adjust accordingly. You should be fine

AuS MaDDoG
Wed 15 September 2010, 04:40
Nick,

I reckon your bracing will be just fine. I would imagine you would be sliding your boards under the table from the end, so you could extend the side braces to the lower rail and leave the others as shown.
I also think that the 50 x 50 x 3 would be more than enough to take the weight of the boards placed into the table without the smaller legs under.

Cheers
Tony.

chunkychips
Wed 15 September 2010, 20:36
Thanks guys,

That gives me a lot more confidence to go ahead.

Tony, you make a good point about the longer side braces so I will do that. As for the smaller legs, more than happy to get rid of those. They're just ugly ;)

Will order steel today!

chunkychips
Tue 21 September 2010, 07:47
I have been accumulating materials ...

Just received my shipment of steel today. I know this stuff is heavy but those x beams are killers!
I'm going to have to find me some pipe-bending gorillas to lend a hand ;)

Also picked up some "Tony" wheels and feet from www.richmondau.com (Thanks for the supplier Tony (AuS MaDDoG)). My feet are 90mm wide with an M12 bolt. The wheels are the S4448 model. See the catalog for specs.

Got my laser cut parts from Rick (rnixon) a couple of weeks ago. Nice bloke Rick. He was good enough to show me the monster MM he built. Great job. The photos don't do it justice.

I now have enough bits and pieces to start building. Just thinking about the best sequence to follow.

So much steel...

AuS MaDDoG
Wed 22 September 2010, 03:26
Hi Nick!!

Looks like you have plenty of work to get on with now :D

Cheers
Tony

Regnar
Thu 23 September 2010, 10:46
Nick those beams might kill you but they sure will break and squish your toes. Just speaking from experience :) If you dont have some I highly recommend some steel toe boots.

smreish
Thu 23 September 2010, 12:01
...and a gantry crane to move them.

chunkychips
Fri 24 September 2010, 01:01
Let's see now..

1. Heavy steel ..... check!
2. Steel toe boots ..... check!
3. Gantry crane ..... hmmmmm ..... there must be forum for DIY gantry cranes somewhere .... :D

smreish
Fri 24 September 2010, 06:50
talk to Greg in AZ, he built his! *and it's really nice*

Greg J
Fri 24 September 2010, 13:16
I bought these plans. $13 (USD).

http://www.synthx.com/shop/product_info.php?products_id=4

A necessity for a one man shop. Good design and after its built, all the back pain goes away. Image that. :)

chunkychips
Tue 18 February 2014, 05:20
Well it's been a little while since my last post. Been busy with life, child No.3 and many other excuses.

All the while the steel I bought back in 2010 has been patiently waiting on the garage floor, taking up space and forming a nice layer of surface rust.:mad:

Well just before the new year I made a pact with myself (and with the Mrs) that I would finish this thing by April. So I have cleared my schedule and I'm back with the program.

If you see me slacking off feel free to poke me with a sharp stick.

lonestaral
Tue 18 February 2014, 05:58
Good for you mite.
Welcome back.
I have built mine and very happy with it too.
Prod, Prod !

darren salyer
Tue 18 February 2014, 06:10
Welcome back, Nick. Show the Mrs. some cool stuff you can build her, and she'll keep you motivated. :)
Good luck with your build.

chunkychips
Sun 23 February 2014, 06:56
Thanks guys.

Have been busy over the last month. Here is where I'm at.

The base (blue part) is all welded and I have done a loose assembly of the x beams and the cross bearers. Seems to fit together and is pretty square.

I guess the rail drilling/grinding is next.

darren salyer
Tue 25 February 2014, 06:24
Looks like you need to be moved to the "Construction Started" area.
Great job!!

pblackburn
Tue 25 February 2014, 19:28
Congratulations on your new home for your thread.

chunkychips
Wed 26 February 2014, 06:02
Thanks. Feels great to be here.
I guess I'm committed now.

chunkychips
Wed 26 February 2014, 06:14
Ordered my racks and pinions from TEA Transmissions in Queensland today.

In total I ordered 4 x 2 metre Module 1 rack and 4 x 20 tooth pinions with custom bore (14mm) to suite the Motion King steppers I have. I'm going with direct drive for starters and will add belt drives later if needed.

All this, delivered to Melbourne cost ~$670. A local supplier up the road from me wanted over $1600 to do the same thing (without delivery) !!! I guess it made the choice simple.

chunkychips
Sun 02 March 2014, 05:34
Started cutting the rails down to size.

It took me hours!. Still haven't finished. Have to wait till next weekend. Hours of noisy tools and good neighbour relations seldom go hand in hand.

Did the Y rails first. They are a little uneven. Any tips for bringing them in line would be appreciated.

I found that if a used washers to keep the section i had cut through, open then I avoided the nasty binding and kick-back caused every time the blade pierces the through the steel.

In the end I was left with a nice 20mm wide strip of offcut steel. This could probably be used as the clamping strip in 10 20 235. To bad I actually bought a separate strip for this. Oh well.

racedirector
Sun 02 March 2014, 06:20
Finished that job a while ago, hated every minute of it. I intentionally cut mine a little tall so I could sand them down to close to 28mm. I used 1/2 the skate and set it for slightly taller than 28mm with a 2mm 115mm cutting disc plus a 24 grit sanding disc on board. Took friggen ages to get them sanded but the finish is nice and smooth plus they are alot more consistent in height than I could ever get by cutting only. As long as your lowest height is above 28mm you should be fine to use a similar sanding method to get them close to even.

Cheers
Bruce

parrulho
Sun 02 March 2014, 08:56
You are in the good track. To do it more precise, in my opinion, you should use a piece of MDF between the rack and the base, like in my photo: http://www.mechmate.com/forums/attachment.php?attachmentid=13659&stc=1&d=1355120867

parrulho
Sun 02 March 2014, 09:14
To correct the rails use a sanding disk (80 grit) on top of a grinding disk, it must be stiff and sand the rails down to 28cm.

your grinding machine should be more in the middle of the wooden base to have more stability. and when cutting do light passes from start of the rail to the end and repeat till finish... it took me about an hour per rail, without forcing.

chunkychips
Sun 02 March 2014, 14:59
Paulo, I think both points (move grinder further back on the mounting block and use gentle passes) are both valid. Initially (see first photo above) I was doing it gently and it was very straight. On the second peice I got impatient and I think a combination of disk flex and possible tilt of the grinder (because it is not further bach on the mounting shoe) caused my problem.

The angle on the right is my first cut. The other is my second.

As for placing mdf under the angle, I don't think it's necessary. I marked my angle iron at intervals along its length and using just the xbeam as a reference it was right on.

parrulho
Sun 02 March 2014, 17:41
Yes, you are right. The first rail is much better. A tip from my mistakes, only advance to next step, grinding the 45 degrees, only after you are sure the cut surface is uniform... :)

chunkychips
Wed 05 March 2014, 09:15
I have spent many evenings reading over the electrical threads as I need to start pulling the control box together. While I now have a better idea of how things go together than when I started I am still a little confused so I am hoping somebody can check over my calculations and let me know if I have understood.

I have
- 5x Motion King 34HS9801 motors - The extra one is for an indexer some day.
- 5x Gecko 203V Drivers
- PMDX-125 BOB
- 2.2kW Chinese Spindle

Trying to figure out the power supply I get:

Power Supply Voltage (DC) = 32 * SQRT(4.1) = 65V

While I have 5 motors, if I use the 5th as an indexer then at any point in time I won't be using all 5 (4 motors for a 3 axis router, only 3 for an indexer since the x axis is stationary).

If this assumption is correct then I only need to consider current draw for max 4 motors which gives:

Max Current = 4 * 4A * 67% = 10.7A

Based on that I need a power supply rated at 65 x 10.7 = 696VA

Looking at the 800W range from antek (http://www.antekinc.com/800w/) (since there are no 700W) I assume I would go for a PS-8N63?

Is this enough or do I need to apply Gerard's 1.2 voltage multiplier rule and get a PS-8N77? Or one of the other values in between (66, 67, 68, 70)?

Also for any Aussies out there is there a cheaper local PS alternative (other than building my own which quite frankly scares the hell out of me)?

isladelobos
Wed 05 March 2014, 16:58
I have the same motors but now i wired in bipollar parallel, use the 8 wires, and now i changed the power supply for another with more Amperes.

You can size up to a posible parallel consumption.

chunkychips
Wed 05 March 2014, 19:28
By Gerard I meant Gerald ... Sorry. That's what I get for posting after midnight :o

chunkychips
Sun 16 March 2014, 20:41
Did nothing MM related this weekend because I spent all my free time removing tiny particles of rusted angle grinder dust from our cars :mad:

Was stuck on there pretty good (including windows). Had to use 'clay bar' and a LOT of elbow grease to remove. Fortunately I was able to remove it.

Note to self (any everybody else who doesn't know) DON'T EVER USE AN ANGLE GRINDER CLOSE TO YOUR CAR.

Lesson learned .... I move on.

Tom Ayres
Mon 17 March 2014, 02:45
You need to start a thread on the main board as a warning or something. Very unfortunate.

chunkychips
Mon 17 March 2014, 15:41
It wasn't all bad. I learned about clay bars and the car came out of it with a showroom finish... :)

MetalHead
Tue 18 March 2014, 03:56
I just never wash my truck so if I get over spray or "stuff" on it, I can just wash it off !! :) !

Tom Ayres
Tue 18 March 2014, 04:06
Why bother? Wash it before you sell it...lol

KenC
Tue 18 March 2014, 04:14
Wash? Let the rain do the job. LOL