My MDF CNC DIY machine--bone stock till the next one :)

[menace]

So after being inspired by others here I decided to have a go at building a cnc machine--the end goal is something I can use to pop out the odd bartop or other wood projects.  Of course buildyourcnc.com was a huge resource for this.  I could post over there but frankly I'm more familiar with this board and it is arcade related, albeit in a diagonal kind of way.

Anyways on to the pictures:  I kept the table at 48"x24" since that's what the plans were and I didn't feel like modifying it too much until I see how it performs.  Here's the end piece--originally i doubled up the table thickness but am not concerned with the reported 1/32 deflection at the midpoint using only the 3/4 sheet--it also made my chamfer's easier:



I started sort of backwards, and moved to the gantry next:  here's the linear sliders--I found these the hardest part since accuracy here is very important for a smooth operation.


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I got the bearings in a bulk lot of old rollerblades--paid about $10 for about 30 or so bearings.

Here's gantry iteration 1:



After looking at it I decided that I would waste too much table space with the router sticking way out there and decided to move it back--we'll see what challenges this makes in getting everything thing else to work out--I can always move it back if it doesn't pan out.



Assembled gantry:



And last but not least a small video (if it embeds right...)

[Yvan256]

That's a really great start, you're already ahead of me! 

If flexing is ever an issue, you could reinforce by simply adding metal "L"'s underneath the MDF, it wouldn't take much vertical space and still add a lot of strength.

My problem is that I can't keep my CNC machine in my father's shop since it would take nearly 50% of the floor space, so I need something smaller than can be moved around.

What router are you planning to use on your machine? Is that a RotoZip in your photos?

[eds1275]

What do you expect the total cost to be after you are done? I see all these people coming out of the woodwork with these things... makes me want one.

[Le Chuck]

Following this build.  Keep it coming!

[menace]

Thanks for the replies!  Small update-- i ordered the electronics from ebay.  By far most expensive purchase but my hopes of finding it local are slim to none..

http://www.ebay.com/itm/200590003120?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Cost to date has been about $100 in hardware and 180 in electronics.  I'll post full hardware and costs later as i am tracking it to see.

As far as the router goes--yup the roto zip is going in--I hardly use it since ironically I find it too wild and hard to control--lets see if the cnc can tame it!  I'm hoping the 270 oz/in holding of these steppers is enough...we'll see i guess.

[Santoro]

Subscribe....

[menace]

Bit of an update--got the y-axis rolling along and test fitted the threaded rod--so far everything is coming together fairly smooth.  I did notice my gantry is .3 degrees off--I guess I can live with that 




 
A few things i have learned from this project.  Center punch every spot you want to drill and the stoopid drill won't wander--also saves you from making endless pilot holes.  Also, use the same measuring device for everything.  You'd think they would all be the same but sadly its not the case...

[menace]

Big update:  got all the electronics in one box--happy with the service from long's motor--super fast shipping--we'll see how the product quality is later i Guess.  I also got the z-axis done but am not really happy with it.  All the 1/16th and 1/32nd errors I have made so far seem to accumulate at this axis it seems. lol--dammit anyways...more pictures later

[Yvan256]

I think you won't have any choice but to move that piece back into the middle. The rod in that picture is in the same place where the Z axis carriage is supposed to be, including the rod for it.

Other than that, nice progress! 

[TopJimmyCooks]

I haven't studied CNC routers built out of sheet goods, So first let me admit ignorance.  Not to be a naysayer, but I just don't understand how that system of four bearings rolling on a piece of aluminum angle can produce desirable CNC precision results.  And yes, 1/16" and 1/32 and 1/64 and .3 degree errors will add up to major issues on the back end, unless there's some mechanism for calibration and adjustment.  combine that with the gantry having two 3/4" mdf legs to support everything . . .   I need to look up some youtube vids of this design running and see what they're cutting with it.  I'm totally into the idea of running a cnc machine and making one - just concerned about using mdf as the basic structural material. 

What happens if you get to the end of it and it doesn't do a good job of cutting?

[menace]

I think you won't have any choice but to move that piece back into the middle. The rod in that picture is in the same place where the Z axis carriage is supposed to be, including the rod for it.

Yeah I didn't think it was going to work but didn't get around to moving it back until today.  With some better planning I think I might have been able to pull it off.

As far as CNC precision goes, if it cuts to within a 1/16" I will be happy--I'm not using it for circuit boards or anything like that--the plan is just flat wood stuff.  If I like it, then once its dialed in, you use the cruddy one to build the next iteration--yes machines building machines--the apocolypse is coming!  The mdf is very rigid and the only deflection i get is 1/16th at center span.  If it becomes an issue, I can double up the deck to make it rigid.  The bearings on aluminum work amazingly well with no appreciable slop so I'm not too concerned about them for occasional hobby use.  If it doesn't do a good job==oh well, i can tweak it.

[TopJimmyCooks]

Cool, keep us apprised of how it's going. 

[Gaaargh]

If I like it, then once its dialed in, you use the cruddy one to build the next iteration--yes machines building machines--the apocolypse is coming!

The real challenge will be to have it build a 4' x 8' cnc.

[yaksplat]

I really want to build one of these, but i have to wait until i build the new house and have room

[mcseforsale]

Subscribed..

AJ

[menace]

Cost breakdown to date (90% complete)

wood--free left overs from other projects--to buy would be 12$ per sheet for 2x4 x 3/4" mdf
roto zip--free as in I already had it.
electronics - 183
couplers         10
hardware         6
hardware and angle 52.34
angle              19.20
cross dowel nuts  19
hardware        36.84

Total = $326.38 including 13% tax

Not that bad considering i could sell the electronics and recoup a good chunk of that...not that I would just sayin...

[eds1275]

Is MDF the best material for this? Doesn't it sag or warp? It's looking great and unfortunately making me want to build one really really bad... but I have a list of 6 other things to do first and money for none of them

[Yvan256]

Any updates?

[menace]

As it so happens--I finally got my couplers in the mail and got them installed.  I had a bugger of a time on the y-axis due to some bad bolt placement but made a work around.  I have also been building scale floats for our city christmas parade--rather than go full siz--we are doing a 1/10th scale entry with mini semi-truck etc.  should be fun..  anyways pictures...





I also built the pc that will be running it but might rebuild it into a smaller case.  Next step will be wiring the whole thing up--just need some 22ga. bundled wire to keep it neat.

[Yvan256]

I'm happy to see progress on that project. I also can't wait to see it completed and see what projects you'll be doing with it!

Be careful, I think one of the bearing is planning an escape with the help of the screwdriver.

[DaOld Man]

DaOld Man likes this project!

[maffewl]

Funny I'm seeing this project on here now.  I just told my wife a few nights ago that building a CNC will be my next project after the arcade, and I was looking at buildyourcnc.com's website.

Can't wait to see how this turns out and very interested in your progress and learning from someone who is building their own the same as I would be.  Nice job so far, keep the pics and comments coming! 

[Yvan256]

Bump?

There's a lot of dead pictures at the beginning of the thread, which is what happens when people use external websites for hosting their photos. 

[griffindodd]

Ahhh poop, I was hoping for a fully documented CNC build thread as I really want to make one. Moving into a new house this year and if ever i could justify the cost of a CNC machine this would be it with all the projects and improvements ahead.

[menace]

LOL - its been so long I got a "necro-thread revival" warning ! I also updated all the other pictures--I forgot I had made an album and moved the pictures there after this thread was made...Anyways, after blowing all the dust off I decided to get this beast going under its own power!  Not much of an update mechanically other than I finally got the router attached but the electronics are working!





The driver board is a TB6560 based 3 axis driver board and is very noisey electronically and has a tendency to miss steps under load.  Fortunately cnczone.com has plenty of advise on how to repair that so that's next.

A small (poorly done) video to show it in action:

http://s388.photobucket.com/user/menace6983/media/MDF%20CNC/20131019_155215_zps764dc6a6.mp4.html

[Rick]

Watching this! Love reading about CNC builds!

Edit: Just watched the video. What sort of lead/ball screws did you get with the kit? (Or did you get them separately?) Is it the screws, or your settings, that cause it to drive so slowly?

[matt4949]

This is Great.  Please post more vids. I'm loving it.

[menace]

the speed is software controlled and im running at 75% power as well.  Figured this way I wouldn't kill it so quickly.  Still have a alot to learn about mach3.

[Rick]

the speed is software controlled and im running at 75% power as well.  Figured this way I wouldn't kill it so quickly.  Still have a alot to learn about mach3.

Cool.

Check out the videos by BuildYourCNC and Joe's CNC 2006 for more inspiration. I'll be honest, I'm addicted to CNC after designing my own a couple of years ago.



I'm since refining my design, moving towards a rack and pinion system... ...likely from CNCRouterparts.com.

Keep up the great work! Can't wait to see yours in operation.

[Yvan256]

Hurray, progress! 

You may want to buy a smaller router bit to reduce the amount of dust generated. 

[Rick]

You may want to buy a smaller router bit to reduce the amount of dust generated. 

Dude, he's using that to resurface his spoilboard so his vacuum table works efficiently!

[Yvan256]

You may want to buy a smaller router bit to reduce the amount of dust generated. 

Dude, he's using that to resurface his spoilboard so his vacuum table works efficiently!

Oh, it's a resurfacing bit, my mistake. Mine's going to be a Dremel #115, I'm working on a smaller scale. 

[menace]

Dude, he's using that to resurface his spoilboard so his vacuum table works efficiently!

Nailed it!  I'm building a 1" thick vacuum board to act as a sort of spoil board as well--hard to explain so once I get it done I'll put up some pictures..The regular bit is a 1/8" bit that came with the spin saw--The bloody thing tears through wood, steel, bone..at 30,000 rpm--i am concerned that it will burn the wood but this is all an experimental thing anyways so i'll play it by ear 

[macattack]

Yeah 30k is way to fast, depending on how fast your axis is moving it should more in the 5-10k range


WWW.Xtremepinball.com

[menace]

What I would love to have is the machine feed setting be maxed out to the steppers specifications and the router rip through the wood like a hot knife through butter    It's important to dream before reality crashes back in LOL

[Rick]

What I would love to have is the machine feed setting be maxed out to the steppers specifications and the router rip through the wood like a hot knife through butter 

Now, that's possible! If you replace "router tip" with "cutter" and "wood" with "fabric". (Or, consequently, just replacing "wood" with "butter".)

[SgtSlaughter]

This project looks great.  I'm interested in building my own, but lack of space right now (currently house shopping, and trying to make a a priority to have the space).  Not sure if you've guys seen the mention on buildyourcnc.com regarding the vertical CNC machine (http://buildyourcnc.com/tutorials/example-cnc-machine-greenLean).  That may be a little more do-able for most people.

[Rick]

Not sure if you've guys seen the mention on buildyourcnc.com regarding the vertical CNC machine (http://buildyourcnc.com/tutorials/example-cnc-machine-greenLean).  That may be a little more do-able for most people.

DAMN IT! That's the exact same idea I theorized, and was toying with three years ago!!! It's almost like they grabbed my design right out of my brain!!!

 

Ah well. I certainly can't fault anybody for it. I mean, I didn't actually build it yet. But, it'll be great to see the idea in operation, and I'll certainly be an early adopter if they put out the plans.

The only challenge I could see is programming the cuts so all of your pieces don't systematically drop out, or worse, drop down onto your bit and cutting into a part you didn't want damaged. That means a strong (!) vacuum table solution, or (evil) tabs, which are the bane of most CNC'ers existence.

[mountain]

Dude, he's using that to resurface his spoilboard so his vacuum table works efficiently!

Nailed it!  I'm building a 1" thick vacuum board to act as a sort of spoil board as well--hard to explain so once I get it done I'll put up some pictures..The regular bit is a 1/8" bit that came with the spin saw--The bloody thing tears through wood, steel, bone..at 30,000 rpm--i am concerned that it will burn the wood but this is all an experimental thing anyways so i'll play it by ear 

Ideally, you will want a variable speed router to dial it in based on the material you are cutting and the speed your CNC is cutting. I used a chip load calculator similar to this one when I was first starting out. I cut everything; MDF, acrylic, aluminum, plywood, sign foam, etc. Acrylic is where you will run into problems the most if you just wing it. You'll either bond the bit to the piece or just have an awful finish on the edges. MDF and wood are a lot more forgiving on the surface, but if you run too fast the heat will dull your bits quickly.


Eventually you will know just by the sound, but that takes time. I landed on a cutting speed (CNC - 120 IPM) that I am comfortable with so the only change I make is with the router's speed.

[Yvan256]

The only challenge I could see is programming the cuts so all of your pieces don't systematically drop out, or worse, drop down onto your bit and cutting into a part you didn't want damaged. That means a strong (!) vacuum table solution, or (evil) tabs, which are the bane of most CNC'ers existence.

That happens all the time when I cut parts on the old Roland MDX-3. If you look at the close-up of some parts it has cut so far in the CNC64 thread, you will sometimes see a weird notch near a corner, that is exactly what happened. I still need to add a "tabs" feature to my own CAD program.

One way to easily clean those tabs is to use a flush routing bit.