New Machine Build- CNC Recycled Machine

[amishx64]

I have been planning out my machine for just about a year now. Through the allotted time of planning, purchasing parts, and planning some more, my machine design has changed dramatically. In fact, the machine design is still changing based on what problems I am having with my various parts, new ideas, and with what resources / tools I have available to me.

When reading about other people's builds it strikes me that others seem to have a substantially lesser amount of problems than me. Either that, they choose not to write about them. Either way, the sheer amount of problems I have already encountered in the designing and building of this machine is so significant it can probably be classified as some sort of phenomena.

The goal of this built was to design a very cheap, smallish machine capable of cutting thin metals, Plexiglas, and wood materials like MDF.

The whole machine has gone through many design changes thus far. The first was to use drawer slides as the primary method of linear motion. This was not bad except they didn't run smoothly and any prayer of precision didn't exist. The next was to use skate bearings and aluminum rails similar to the common gas pipe design of this forum, where the bearings would ride on top of the rails. The problem here was cost, the bowing of the aluminum rails, and that the bearings kept slipping and were misaligned. The third was to use skate bearings and cold rolled steel square for movement. After a bit of experimenting, the idea fell through because of cost, complexity, and the lack of precision tools on hand. The current design I am experimenting on utilizes a stainless steel hardened rail design and seems to be promising.

Currently I have a fairly solid box-shaped frame with two rails and x-gantry mounted inside. The rails are 8mm in diameter by about 13" long. The material holding the rails to the insides of the box is remolded HDPE #2 plastic. I also used two pieces of HDPE on the gantry as slides for the x-axis which is bolted to a piece of MDF. With the aid of some WD-40, the x-axis gantry slides very easily. This is my first break of luck thus far in the project and I am very pleased.

For the stainless steel hardened rails, I scavenged for old ink jet printers. Thanks Craigslist. 8mm is the common rail size for ink jets from what I have seen. For the remolded plastic, I saved cleaned out milk cartons. I took a paint stripper, heated the milk carton up and forced the molten plastic in a 3 inch tall by ~ 1.25 x 1.25 piece of cold rolled square steel tube. I let this cool in water then forced the two materials apart (with a hammer). This yielded very good results with very little (completely negligible) air pockets, and a very solid piece of plastic - all for free.

For now, I am working on the y-axis and some couplers I am not having a fun time with. The all thread rod is bent coming out of the aluminum coupler and the coupler is not at fault as far as I can see, as I didn't make it.

Pictures in a bit.

[amishx64]

Alright, here are some pictures of the x-axis setup. This thing moves very easily and smoothly with almost no wiggle at all.

[amishx64]

I've built my y axis stage but it is not as I had hoped. The Z axis mount thing wiggles back and forth like crazy and the Y axis doesn't slide quite as well. I am going to need to make some more plastic blocks as sliders or rethink the Y axis design. Perhaps with steel and bearings? Pics on the current setup in a few.

I am probably going to go out and get a cheap drill press form someone on Craigslist or Harbor Freight. Any word on how the drill presses are at Harbor Freight quality wise? Do I need to be worrying about the speed ratings I see with the drill presses?

I really like the article on how to make your gantry rock solid and I may implement that on my X axis and also Y axis once I rebuild it. I am thinking v-grove bearings and some steel wire similar to that of bike brakes.

[FandZ]

I have the harbor freight drill press. I got it for around 60 I believe. It gets the job done. 0 complaints there. Just get a punch and punch where you want drill and it'll drill true. It has belts so you can change the speed for different metals. I do wish I would have waited for the one with the key less chuck to come in stock. It can be a pain when you are drilling up to size.

[CarveOne]

Originally Posted by FandZ I have the harbor freight drill press. I got it for around 60 I believe. It gets the job done. 0 complaints there. Just get a punch and punch where you want drill and it'll drill true. It has belts so you can change the speed for different metals. I do wish I would have waited for the one with the key less chuck to come in stock. It can be a pain when you are drilling up to size.

You can remove the chuck and install a keyless chuck on it. There is a wedge shaped tool that is used to pop it off the spindle arbor. A key type chuck will grip a drill tighter, but keyless works well for most things. Do a web search on drill press chuck removal for other info.

http://www.jacobschuck.com/drill-chuck-install.asp See illustrations B and C.

CarveOne

[amishx64]

Here are the said pictures. I only have one plastic block sliding on dual 8mm and 7 mm rails with a center hole for 5/16" all thread. The wiggling / stability problem is most likely due to the fact that I have only one block on the y axis. I am probably going to end up making two new HDPE blocks with hopes of better stability.

If you take a look at the first image, you can see how the hole on the bottom 7mm rail is severely warped. Bad drilling on my part. That needs to be fixed.

[amishx64]

Going to Harbor Freight to hopefully pick up a cheap drill press and mounting vice tomorrow. I will keep you guys posted with pics.

[FandZ]

Originally Posted by amishx64 Going to Harbor Freight to hopefully pick up a cheap drill press and mounting vice tomorrow. I will keep you guys posted with pics.

Yay power tools. They give a build so many more options.

[amishx64]

Originally Posted by FandZ Yay power tools. They give a build so many more options.

Yes that is what I am intending to have happen. That and more precision.

I got the drill press yesterday. I haven't put it together yet but here are the pics so far. I got the drill press for a great price at Harbor Freight - $43 with a coupon. Pics after I put it together today.

http://www.harborfreightusa.com/usa/...o?itemid=44506

[FandZ]

Originally Posted by amishx64 Yes that is what I am intending to have happen. That and more precision. I got the drill press yesterday. I haven't put it together yet but here are the pics so far. I got the drill press for a great price at Harbor Freight - $43 with a coupon. Pics after I put it together today. http://www.harborfreightusa.com/usa/...o?itemid=44506

I have a feeling you are going to be investing into some skate bearings soon.

[amishx64]

Originally Posted by FandZ I have a feeling you are going to be investing into some skate bearings soon.

HAHAHA FandZ, you are correct, I already have invested in skate bearings and I may be getting some more if I can't get this DIY recylcled HDPE plastic slide stuff to work correctly. I am working on an alternate linear rail design in case the plastics don't hold up, and yes, it uses skate bearings. Oh, by the way, thanks for the info on your Harbor Freight drill press. Mine is a keyed chuck also. :-\

Here are some pics of the assembled drill press. I have to say it's not the best quality, and it is a tad small, put it's great for only $43. The vice I bought for it is only for bigger drill presses I guess. The material holder on the drill press has holes for mounting things (like my said vice) but the slots are much closer together that the ones in the vice. See pic.

The drill press drills very well, and I found that a 1/16 pilot hole is necessary for any hole, otherwise the thing is always a bit off mark.

[CarveOne]

Look at the stampings on the drill chuck to see which taper it has and find a new key less chuck with the same JT number on it. HF sells them. Then check that link I posted earlier about how to remove and install the chucks. Lowes and Home Depot sells Jacobs brand chucks. You can install a 5/8" chuck if it has the same Jocobs taper. Some 5/8" chucks won't fully close on a 1/16" drill and smaller, so make sure it says 0-1/2" or 0-5/8".

CarveOne