MadModder

"Interesting upgrade project", yes indeedy.

I got the 400 x 600 x 30mm base cut to size, and all the sharp edges taken off.  There's a lot stuff that needs to be bolted to the base, I'm thinking drilling & tapping will be best.  I'll just use longer screws for more thread engagement in the plastic.  It's HARD plastic, but it IS plastic.  I knew there was a good reason that I bought that push-pull power tapping attachment.

My 12mm rails arrived a couple days ago.  I first ordered the rails about 3 weeks ago, when they showed up I lifted the box I thought "My God, this is an awful heavy box for 12mm rails."  Turned out they were 20mm rails, I checked my order and sure enough that's exactly what I ordered.  When I contacted the seller about returning the rails, he made a counter offer.  He offered a 40% refund and I just keep the rails, saves both of us the hassle of returning them.  So now I have a pair of 20mm diameter, fully supported linear rails that are 1m long for some future project - with 2 sets of bearings.

I got the X axis 12mm rails cut to length yesterday.  I needed 450mm of rail for an exact fit, I cut them to 430mm so I could move them around a bit if needed.  The rails are hardened so I had to use the spinning wheel of death in an angle grinder to deal with them - I don't want to have to cut them more than once.  When I started mocking things up I discovered that by some happy coincidence the bottom of the bed is exactly 1/4' above the top of the bearings - talk about dumb luck!  And I just happen to have a couple of short chunks of 1/4" x 2" aluminum flat stock laying around. The bed will be in the original location, so no mucking about with the X axis leadscrew.  I think I can keep the Y axis leadscrew in the same spot, but when I print the replacement Y axis carriage I'll most likely need to move the lead nut location.  The new 2040 extrusions for the Y axis rails should be here in the next day or so, then I'll have a better idea what things could/will look like on the gantry.

Well, one nice thing about them (I don't own one btw) is that they are cheap and accessible. A heavy machine with powerful motors and spindle is out of reach for many. And they make an interesting upgrade project, which sounds like what we're in store for here! 

Yes, glad to see you working on it, too, Andrew. Though it also looks like a pain! Reminds me of a giant scale version of my little plastic welder's problem -- which I never did fix, BTW. 

I recently purchased a small CNC router, fully intending to heavily modify it and turn it into a more respectable machine. This machine started out life as a Vevor 3018, the previous owner had upgraded it to a 4030 and upgraded the spindle to the high speed spindle motor. As built, these machines are real lightweights, the frame is made of 2020 and 2040 aluminum extrusions. But, Awesome CNC Freak has shown that with some TLC these little guys can be used to do useful work. He's machined a lot of the parts for his DIY 5 axis CNC using his modified 3018.

These are some of the cons that I see and what I plan to do about them:
1) It's a lightweight, it has no mass to it, and no base. I plan on adding a substantial base to this little guy. The first plant I worked in made laminated plastic sheets, I saw them make sheets anywhere from about 20 thou, up to 11 inches thick. In the years that I worked there, I accumulated several of their rejects. I'm going to use a 400mm x 600mm part of one of those 30mm thick sheets to make the base that every thing else will be bolted to. That 400 x 600 x 30 mm piece weighs over 20 pounds, and I can bolt that to the bench if needed.
2) They only used 10mm guide rails, those things will flex like crazy. I'm going to up-size the 10mm unsupported rails, to 12mm fully supported rails. Just going from 10mm to 12mm rails would be an improvement in rigidity, but using the fully supported rails should make that an orders of magnitude improvement. The X axis rails will be bolted to the base, further increasing their rigidity. The new 12mm Y axis rails will also be fully supported, and bolted to new 2040 extrusions - instead of being just a 10mm rail hanging in space.  I also plan on bolting those new 2040 extrusions together, which should also help to stiffen up the gantry.  If I have to, I can use this guy to mill out new gantry side-plates out of some more of that 30mm stock.
3) The Vevor control board leaves much to be desired, it's being replaced with an ESP32 control board with MUCH better stepper drivers.
4) They used about the cheapest, lowest torque Nema 17 steppers possible. There's no ID on them at all, but they're about the right size to be the 40-ish oz.in version. I already have MKS42 closed loop stepper controllers for these guys, If I need to upsize the steppers, I can go to 84 oz.in or 92 oz.in steppers in Nema 17, and still drive them with the MKS42's.
5) The stock Z axis just plain sucks, it's made out of injection molded plastic and it's only got 40mm of travel. It also has 10mm rails, but they're a LOT shorter that the X or Y axis rails so that alone makes them much stiffer. I can 3D print a temporary replacement that will give me more travel while working on a permanent solution.
6) The spindle, where to start, it's a GS-775M , 20K rpm, 75W motor. But at least it's got an ER-11 collet adapter on it. I can't complain too much I guess, my Unimat's motor is 100W, my Sherline's is about 125W, and my first CNC - back in the late 90's -  had a whopping 60W spindle motor. Awesome CNC Freak used a 200W motor with a speed reducer in his 3018, might do something like that. And then there's always that 1KW water cooled spindle and VFD that's been sitting in a box waiting for me to finish its' project.
7) This thing is drip-fed g-code through a G-code sender, I've got a used Tiny PC coming that will do just that. I've accumulated a DDCS stand alone controller and stepper drives over the years, which are also a possibility.

This and my other unfinished projects will keep me busy over the winter.

Don

Haas use electric cooker elements (the spiral ones) stacked to give the required resistance