New DIY CNC (not MPCNC)

So I wasn’t really going to post about this here, since there really isn’t much MPCNC left in it, just the controller really. However since I have now posted 3 other threads asking for help and got exactly what I needed each time, I figured I’d share. I had been posting on the OpenBuilds forum a little bit, but didn’t get that same sense of community…in fact my threads were often just a dialog with me and one other person.

Coming back here and seeing so many familiar names still posting, helping, and being generally awesome just reminded me why I built my original MPCNC and got me just browsing the forum again for fun.

As I mentioned in some of my other threads, I had built a Burly back in, I think 2020. I loved it. Wasn’t my first exposure to CNC as I do some for work now and then, but to have one that was MY toy was awesome. I made alot of cool stuff, learned alot, but also wanted MORE.

My Burly was built large, as I wanted 1/4 sheet of plywood capability…but I also couldn’t resist the call of aluminum. I think you all know where this is going. I developed tolerance issues that were unacceptable to me, even in wood.

I made one half-hearted attempt at upgrading the machine, replacing my short axis with linear rails. It worked a little, but still didnt get me where I wanted to be, and it was almost impossible to change tools. So I decided to start from scratch.

I thought even about buying a ready made machine, something like the FoxAlien Vasto…but the price tag was high and the working area was half of what I wanted. I KNEW I could DIY something good, but I just didn’t have a concept I could wrap my head around.

Thats when I found OpenBuilds. It was a revelation…not their machine designs, as thats not what I ended up with, but as a supplier of aluminum extrusion. I always thought large 2020 style extrusions were prohibitively expensive (and if you go to say, McMaster-Carr, they are!), but after I priced out what I needed, I realized I could get what I wanted at a price I could swing.

Now, mind you this machine so far has cost me 3x what I paid to build the burly, but I am at a point in my life where I can swing it, so why not. What I DONT like about the OpenBuilds design are the use of 8mm lead screws for ALL axes, and using Delrin V-wheels for motion. So, my machine is the marriage of an OpenBuilds style C-beam frame, with import linear rails on all axes, and ballscrews on X/Y. The spindle is an import 1.5kw 400hz ER16, air cooled with VFD drive.

I tried to keep custom parts to a minimum, but what needed to be made was cut from 1/4" and 3/8" thk MIC6 aluminum tooling plate on my manual knee mill (I know, I had a builder’s advantage there). I am nearing the end of the build, all that is left is endstops, spoilboard, an enclosure (maybe, its big), and dust collection. I may also consider the RapidChange ATC since you fine people on this forum helped me get reverse working on the spindle.

Anyway, enough talk. I have’nt taken ALOT of pictures, so I can snap more if anyone is interested. Thanks for being a GREAT community!

11 Likes

2 Likes

Spindle in

8 Likes

So far that build looks great, I honestly do not see anything I would change at first glance.

Please keep an eye on the costs I am very interested in that. I am at a point where I might make a few “upgrades” optional if the juice is worth the squeeze. Looking at this build I would have guessed more than 3X but if that is really the case I need to do some price shopping again.

2 Likes

Thanks for sharing this. I think some of us aspire to get to this, but aren’t there yet, so it is nice to see what goes into it and provides at least me some idea of the details. What size are those NEMA’s on the Y axis offset by the belts… why not go direct drive rather than belt-offset (is there a gear ratio in there)? In that last photo, they look larger than 23, but it may just be the perspective.

Came for the CNC, stayed because of people!

3 Likes

I just so happen to be keeping an accounting of this project cost to the penny. I am doing this both to prevent gross overspend (death by 1000 cuts type of thing), and also to ensure that I come in UNDER a turnkey machine. The FoxAlien Vasto with spindle and laser was $2800. This is my target to stay under, which doesn’t even take into account the fact that a table, enclosure, and dust collection are NOT included in that price.

I am CURRENTLY at $1,628.43. Give or take some considering there are always things you have on hand (limit switches, nuts/bolts, a mini-rambo, etc). But this number is a good encapsulation of the cost so far. This leaves $1,100-$1,200 or so to finish the spoilboard (im going to incorporate T-track), build an enclosure, dust collection, and buy a laser head. All in all, I think I will get close to the $2800, but have a machine with twice the working area.

4 Likes

I would have thought you would be a lot higher than that. This is awesome! Thanks for sharing!!!

All of the motors are NEMA23. I WAS going to incorporate a gear ratio in the Y motors, but I had problems with skipped steps during jog. Turned out I didnt need it when I found 10mm lead ballscrews, so the belts are driving the Y 1:1. I still like them though, as I feel the belts make the motor mount more convenient for footprint and servicing.

The X motor DOES incorporate a 2:1 ratio…why? Because I bought the X-screw during my half-baked MPCNC “upgrade”, and was a dummy that bought a 5mm lead ballscrew. The Y screws are 10mm lead, so the ratio on X makes it so my speeds and steps/mm match on X/Y.

Now, I know I am not getting the max performance on the NEMA23s with the mini-rambo. These motors are rated for 2.8A max, and are being driven at 1A. Once I start cut testing, I will learn very quickly if it will be up to the task or not. I haven’t decided on a replacement board yet. Cross that bridge when I get there.

Me too! Like I said at the start, I thought a metal frame machine was out of reach, but the OpenBuilds extrusions for a machine this size are pretty reasonable, and the build flexibility afforded by the extrusions and off-the-shelf hardware made design and build MUCH simpler than I expected. It was like the creative floodgates opened.

Of course, the import rails, slides, screws, and spindle really help manage the cost too…we’ll see how long it all lasts, haha.

1 Like

Don’t laugh, you were one of them! I was glad to still see you active.

Even when I was more active, I was always somewhat of a lurker, but always enjoyed your posts.

4 Likes

This place has so many great people. My biggest pet peeve is that I’m located very far from everybody else! Not easy to visit the maker faires and hangouts. I’m currently trying to get a makerspace community growing here in Tromsø. I don’t think it’ll be every as active and full of knowledge as this forum, but I hope to find people IRL as well. But I’ll never leave this place, at least as long as I keep tinkering!

2 Likes

That’s a great looking build, and thank you for sharing your details and build experience.

I would have guessed that you spent a fair bit more than you did so far.

Yeah. But on the other hand

4 Likes

Haha, well, usually I would admit that I’m kinda happy living far away from all the heavily populated areas, conflicts and bigots. But you guys are not such! :smiley:

2 Likes

A very compelling argument…but on the other hand I can wear shorts nearly every day of the year!

Norway looks like the most beautiful place on the planet…but man I don’t know if I could deal with THAT cold! I connected through Oslo on my way to Italy once, sadly didn’t have enough time to leave the airport…

1 Like

The area around the airport of Oslo is very boring. Flatlands and forests.

But yeah… the cold… on one hand you get used to it, on the other hand… sigh

So how do we think the jackpot would get on with NEMA23s? I think the 2209s go up to 2A, with a 2.5A burst? Doesn’t sound too far off my motor ratings.

Why do you do belts to your Y axis instead of motor directly into the ballscrews?

For the possibility of gear reduction and ease of mounting.