Plywood CNC Build

[Stu.]

I never know how to start threads cleanly, so here goes with spiel.

I have a couple of guitars that are ready for fingerboards, which I would usually break out my tiny CNC for. It’s been playing up recently and I basically don’t trust it anymore, therefore it seemed like a good time for an upgrade! Being a hobbyist, I can’t afford to spend thousands on anything off the shelf - instead, I purchased some plans from BooTec for about £6 and got to work.

The frame is 18mm ply, with Nema 23 steppers and SFU1605 ballscrews for linear motion. DM556 drivers and Arduino UNO with CNCShield inside. I painted it blue because Wickes plywood is ugly. 

Anyway, I finished the wiring yesterday and worked out the final gremlin this morning.

 

 

 

 

 

 

 

 

 

 

[MiKro]

Good for you on this build, at least you used decent linear rails and ball screws to start with. The Ply frame will give good service for wood working and also will give you a chance to really evaluate the CNC need and usage.  The accuracy may suffer some  due to the ply but with wood should be of no real problem. Make sure the Ply is sealed well even though it is painted.  Kudos!!!

ps I would move the electronics though as wood dust will get to it where they are  now.

MK

[Stu.]

6 hours ago, MiKro said:

Good for you on this build, at least you used decent linear rails and ball screws to start with. The Ply frame will give good service for wood working and also will give you a chance to really evaluate the CNC need and usage.  The accuracy may suffer some  due to the ply but with wood should be of no real problem. Make sure the Ply is sealed well even though it is painted.  Kudos!!!

ps I would move the electronics though as wood dust will get to it where they are  now.

MK

Thanks, man. I do have a piece of ply to place over the top before adding a spoilboard, but you’re right and I will be monitoring the dust. Cooling might be an issue too.

 

The 775 motors and ER11 collets in my inventory have awful runout, so I’ve ordered the equivalent of a Makita RT0700C with an ER11 on the armature. Speeds up to 30k RPM, no need for a power supply, and an accurate ER11 system with warranty.

 

 

Edited March 2, 2023 by Stu.
Adding photo

[henrim]

Looking good. I think I have found a neck shape I like the most and I just would like to repeat it in different woods/materials. I have been thinking about building a cnc myself but when I choose components the cost always creeps beyond commercial entry level systems (shapeoko and likes). Plywood frame could be the thing to get me started. Quick, inexpensive and most likely accurate enough to rough out necks. Although lately I have been thinking about just building a router sledge for that purpose.

[Mr Natural]

wow. seriously impressed. I dont really know much about CNC- but I am impressed with this so far. Cant wait to see what it can do. Great job so far man.

bravo. 

[Stu.]

7 hours ago, henrim said:

Looking good. I think I have found a neck shape I like the most and I just would like to repeat it in different woods/materials. I have been thinking about building a cnc myself but when I choose components the cost always creeps beyond commercial entry level systems (shapeoko and likes). Plywood frame could be the thing to get me started. Quick, inexpensive and most likely accurate enough to rough out necks. Although lately I have been thinking about just building a router sledge for that purpose.

Thank you! Check out the BooTec video series for some inspiration: It's a really straightforward design and definitely DIY/hobbyist ability level.

The real cost here is from the linear motion parts - the linear rails and ballscrews are quite expensive, but they're very solid. The ballscrews are very smooth and have absolutely no backlash, which is a huge upgrade compared to the T8 leadscrews I was using before. I did some research on stepper drivers and went with a slightly more expensive unit (DM556) for each motor, because I'd read about the cheaper drivers missing steps, overheating, and whining. I also didn't both with limit switches. I tend to just zero near my workpiece and then execute within a small area.

1 hour ago, Mr Natural said:

wow. seriously impressed. I dont really know much about CNC- but I am impressed with this so far. Cant wait to see what it can do. Great job so far man.

bravo. 

Kind words, thank you!

Hopefully I can run the first operations after mounting the spindle tomorrow. I calibrated yesterday, so should be good to go and fingers crossed!

[MiKro]

@Stu., I do have a question for you. Did you use metal inserts in the wood to screw down the linear rails and bearing blocks?  I have a friend, whose son  is wanting to build a Plywood CNC after seeing yours. Something I told him about last year was an option and keep cost down for now. DUH!! LOL!!

MK

[Stu.]

7 minutes ago, MiKro said:

@Stu., I do have a question for you. Did you use metal inserts in the wood to screw down the linear rails and bearing blocks?  I have a friend, whose son  is wanting to build a Plywood CNC after seeing yours. Something I told him about last year was an option and keep cost down for now. DUH!! LOL!!

MK

Ha! That's always the way.

The linear rails are just held in with 3x20mm wood screws - I'm hoping that with screws every 25mm, there will never be enough weight on a particular area to pull them out. I guess we'll seen how that goes! The bearing blocks are just held in with 10ga screws. I didn't go too crazy, because they're supported well in Z and Y, and then both sides of X are supported by the gantry and linear rails. It all seems to be holding for now, but threaded inserts might be needed in the future.

[Stu.]

We have a spindle/router and test runs are good! I don’t have any means to measure the runout, but it looks very stable and cuts like a knife through butter. The other motors had at least 0.5mm of runout.

 

 

 

The working area is enough for a normal guitar body (non-spiky) and 25.5” scale fingerboards.

 

[Stu.]

This CNC is working well so far! I’ve managed to get my fingerboard mounting jig sorted, started cutting some MOP, and finished by adding some personality.

 

 

[curtisa]

I see you've...vandal-eyesed...your machine.

[Stu.]

22 hours ago, curtisa said:

I see you've...vandal-eyesed...your machine.

This response made my evening yesterday. Cheesy little puns and jokes are the best!

[woodfab]

Wow very nice.

[ScottR]

Yeah, I'm stunned. This has gone way past your blue jeaned guitar.

SR

[Stu.]

15 hours ago, ScottR said:

Yeah, I'm stunned. This has gone way past your blue jeaned guitar.

SR

Thanks, Scott! My favourite thing about it is that it works!

[mistermikev]

Damn... look at you son... built your own cnc and making cool stuffs right off the bat.  Impressive.  Looking fwd to you breaking a champaign bottle over your first cnc build!!  "you go boy"