2-axis ghetto cheap

[blades]

I've mentioned that I'm doing a super-cheap 2 axis conversion on my HF 44991 mill, and this thread shows my progress so far. But first, a word about my project.

I very much admire the conversions that Hoss, skmetal, Adam, and others have done or are doing. They are done right, and done with a very high level of quality and expertise. In fact, they're done the same way I would have done it myself a few years ago when I was machining for a living, and had almost unlimited resources for materials & machine access. Hat's off to you guys, keep up the great work and updates on your machines!

When I got my mill a few weeks ago, I had no immediate plans of CNC-ing it, until I saw what can be done. I decided to take my project in a different direction: how cheap & easy can someone do a 2-axis conversion? 2 axis is perfect for me, as I only plan on doing limited 2D profile machining on plastics or occasionally aluminum. The way it sits right now, I have about $140 into it. $100 for the complete 2 axis setup I got off ebay, and $40 for the timing pulleys & belt.


Pic 1 shows the incredibly simplistic components I made to complete the stepper mounting. The Y mounting brackets are 1" angle iron, and are mounted to the Y axis hub using the M5 tapped holes that go thru it. Note that NO modifications needed to be made to the machine. I may decide to do some minor mods when I mount the controller and run the cables. I presently have the timing belt tension just about right. If and when it stretches, I'll have to add a belt tensioning device to it. The X axis drive is a simple aluminum shaft that engages the slot in the end of the leadscrew. I opted to use Lexan for the mounting plate because it was readily available and easy to work with. I may at some point make nicer aluminum mounting brackets for both X & Y axis, but first I'll see how it works. Next phase of the project is getting the controller mounted and the cables run neatly. If all works well, then I'll come up with something to shield the belt & motors.

Pic 2 shows the timing pulley: the I.D. was bored out to 20mm, and it simply replaces the number dial.

[epineh]

I like how you used the angle iron, I have "filed" a few pic's for future reference. Keep the pics comin

Russell.

[DogWood]

Very Nice, sweet and simple. I love it!

[hoss2006]

I can't say I like your setup there blades, I love it.
American ingenuity at it's best.
I love simple designs that get the job done with the least hassle.
That would be a pretty easy kit for you to sell.
Hoss

[Oldmanandhistoy]

Hi Blades,

Your Y axis set up is almost identical to what I did as a temporary set up for a power feed on my mill (not an X2). The difference was that I made a new bearing block to add two radial bearings between my thrust bearings. The hand wheel was removed as I didn’t like the idea of catching it when at full tilt under CNC control.

So how do you think your thrust bearings will cope with the side load from the belt tension; do you foresee a problem over time? Reason I ask is if it’s not going to be a problem I may do the same on an X2 that I already have, to use for a CNC drilling machine.

Thanks for sharing btw

John

[Mr.Chips]

Did you install more precision ball screws? Didn't notice a mention of that. But then my wife says I can hardly find anything.

Thanks
Hager

[kanton]

Neat! What can you do with the Z axis?

[blades]

Hey guys, thanks for the kind replys! Wasn't too sure how well this ultra-simplistic setup would be received.

Hoss: thanks man! I definately developed it with an eye towards kitting it.

oldmanhistory: I don't have any thrust bearings on the Y axis, only the OEM setup, and yes, I do forsee problems on a long-term basis, due to the fact that there are no bearings. This is definately on-deck for future improvements. For now, I will just keep it well greased.

Mr. Chips: no, no ball screw for now (part of my ultra-low-cost design). I originally thought about using some new 10 pitch acme screws, but decided with the smaller motors to see how it works with the OEM 16 pitch. Ball screws would have required machine modifications, which I wanted to avoid at this time (part of the KISS principal again)

kanton: no plans for Z axis conversion. There's a lot you can do with 2 axis, but it requires more "hands-on" when running a program. Years ago I ran a 2 axis Tree CNC mill, and absolutely loved it. Was especially nice for drilling hole patterns. You could quickly traverse to different hole locations without concern of Z axis programming. Can't really do any true 3D machining though. Since I'm not looking to get that fancy, the 2 axis will suit me well.

More to come later. Next step is to hook the controller up and see how everything moves, and what kind of power I have at the handles. I already know with the 16 pitch leadscrew that I won't have blazing fast jog speeds. Also have to come up with a CAM program that will recognize the controller board.

Wish I didn't have to work all weekend!

[kanton]

This project is so neat I may want to copy it, but I want at least a three axis machine. Does anyone know if two of these packages could be used together to get a three or four axis machine?

Also, does anyone know which "Two powerful high quality 12 volt 600maH, 1.8 degree, 200 step per revolution motors custom manufactured by Shinano Kenshi" come with this package?

Thanks,

[blades]

kanton, the motors may not be up to the task of raising the head, unless you have a really good counterbalance setup that minimizes the required lift force. The website that is associated with the ebay sale strangely no longer lists the package on their website. When it was on there, they said the steppers were "... over 100 oz in torque". I know this is well below what most guys are using.

Maybe it would be possible to use 2 of these motors on the Z axis? I guess you'd have to do the math and see if it's financially worthwhile to pursue it.

[chukkie]

My 1st post – so bear with me.

Has anyone tried installing a Stepper Motor to the Z-axis fine wheel feed using the same method as blades did with his Y-axis and the timing belt?

I know this would not be the best way but would be a cheap way and you could simply use the stock mechanism to engage and disengage for manual use.

Also the low power motor should turn Z-axis fine wheel feed – I think.

[Harryman]

Blades, that's an awesome, quick and dirty way to get up and running!

Love it!