My CNC tapering machine progess

[snipershot]

I started working on this about a year ago, and Ive built and tore it back down several times and redisgned it. Ive made more mistakes than I can count, and Ive ruined a good deal of metal along the way. Lol. Its still not done, but Im happy with the direction its going now.

Joe

 

[snipershot]

more pics.............

 

[snipershot]

Stepper motor mounted....

 

[iusedtoberich]

Nice job. Is that an Atlas headstock?

May I suggest using flexible couplers at the stepper shafts? I had a cnc with rigid ones like you have and they led to problems. You can get flexible ones from MSC for about $20 each. I had bought many different types for a work project I built and they all worked well.

 

[GBCues]

Looking good and solid to me so far.
My only comment would be on the extension you made for the stepper motor. Getting the axis of the driven part aligned exactly with the axis of the stepper motor is very difficult. Since it is a rigid design, there could be a little stress or wiggle induced there and that will have a tendency over time to loosen the set screws. I use a flexible no backlash metal extension on mine. Even so, those set screws working loose has been an occasional problem for me.
But like I said, it is looking very good!
Enjoy!
Gary

 

[iusedtoberich]

Looking good and solid to me so far.
My only comment would be on the extension you made for the stepper motor. Getting the axis of the driven part aligned exactly with the axis of the stepper motor is very difficult. Since it is a rigid design, there could be a little stress or wiggle induced there and that will have a tendency over time to loosen the set screws. I use a flexible no backlash metal extension on mine. Even so, those set screws working loose has been an occasional problem for me.
But like I said, it is looking very good!
Enjoy!
Gary

They also make the couplers with a clamp on design instead of a set screw design. The clamp on is probably a more secure connection. I believe they use two screws in tension to provide the clamping force, but I don't have one in front of me now...

 

[snipershot]

Nice job. Is that an Atlas headstock?

May I suggest using flexible couplers at the stepper shafts? I had a cnc with rigid ones like you have and they led to problems. You can get flexible ones from MSC for about $20 each. I had bought many different types for a work project I built and they all worked well.

Yes it is an atlas headstock and tailstock. I figured it would be perfect for this machine because its solid as a rock, and would be precise. Im gonna look for those couplers asap. In the pics, the stepper motor on the cross slide isnt mounted to the bracket yet, so thats why it looks crooked. I like the idea of the flexible couplers though.

Joe

 

[GBCues]

Joe,

They are readily available on eBay. They look like this (wasn't sure from your response if you knew what we are talking about)

HTH

Gary

 

[snipershot]

Thanks Gary, i was just looking at something similar on MSC's website. Thanks!

Joe

 

[iusedtoberich]

Man, I was just at the office and for got about this. I had a project a couple years ago where I needed a coupler. Since it was the company's dime, I ordered every type they offered at MSC. I still have them all and wanted to take a picture of the different types. Sometimes its hard to tell from a catalog. The type JB linked are very good for your application.

Here's the type I used for my work application in the attached pic. You can buy different hardnesses of the plastic material between the two pieces of aluminum, to allow for more shock absorption. After trying a few different types though, I would go with the type JB linked for a CNC.

 

[iusedtoberich]

Note* I never completed my machine, so the following is not proven out...

It looks like you already put a lead screw in. If you want to consider a ball screw for futre machines, you can get them new for about $1 an inch in the rolled type, but US made. This is only in the 5/8" diameter (which should be fine for this). The diameters above and below are actually more expensive. This is the "value" diameter. And the ball nuts are about $20 each. So you can buy two ball nuts to make your own anti-backlash nut, if you wanted to. I got mine I believe from Reid Tool supply.

My info is dated, 10 years, but I think the prices might still be the same. I was gung ho at the time to build a cnc lathe, but then lost interest. I bought an Atlas like yours for $100, that was 18" or 24" between centers, and then I found a 54" long bed on ebay for another $100 or so. What I was going to do was bolt the linear bearing rails to the top of the lathe bed, to build a new carriage and cross slide. Then use the existing headstock and tailstock like you did.

Anyway, I took the lathe all apart, bought all the linear rails, servos, drives, etc, and then said I'd do it later. 10 years later its all still in my crawl space! lol.

Have you thought about the cross slide yet? You can make a plate that is drilled and tapped in many locations, that you can then mount multiple QC tool posts to. If you only use the lathe for tapering that probably won't gain you much. But if you end up using it for turing metal (for fun, or for your cues), you can mount multiple tools at the same time, one in front of and one behind the center axis.

What about the spindle drive? My Atlas had a huge belt drive train hanging out the back. I was planning on junking it all, and just driving the headstock with one belt and a VFD controlled motor.

Best of luck to you! Keep us posted of the progress.

 

[snipershot]

Note* I never completed my machine, so the following is not proven out...

It looks like you already put a lead screw in. If you want to consider a ball screw for futre machines, you can get them new for about $1 an inch in the rolled type, but US made. This is only in the 5/8" diameter (which should be fine for this). The diameters above and below are actually more expensive. This is the "value" diameter. And the ball nuts are about $20 each. So you can buy two ball nuts to make your own anti-backlash nut, if you wanted to. I got mine I believe from Reid Tool supply.

My info is dated, 10 years, but I think the prices might still be the same. I was gung ho at the time to build a cnc lathe, but then lost interest. I bought an Atlas like yours for $100, that was 18" or 24" between centers, and then I found a 54" long bed on ebay for another $100 or so. What I was going to do was bolt the linear bearing rails to the top of the lathe bed, to build a new carriage and cross slide. Then use the existing headstock and tailstock like you did.

Anyway, I took the lathe all apart, bought all the linear rails, servos, drives, etc, and then said I'd do it later. 10 years later its all still in my crawl space! lol.

Have you thought about the cross slide yet? You can make a plate that is drilled and tapped in many locations, that you can then mount multiple QC tool posts to. If you only use the lathe for tapering that probably won't gain you much. But if you end up using it for turing metal (for fun, or for your cues), you can mount multiple tools at the same time, one in front of and one behind the center axis.

What about the spindle drive? My Atlas had a huge belt drive train hanging out the back. I was planning on junking it all, and just driving the headstock with one belt and a VFD controlled motor.

Best of luck to you! Keep us posted of the progress.

I bought a linear stage off ebay last year and thats what I used as the base. It already had the leadscrew and carriage installed. I had to make a bracket and press in a bearing to hold the other end of the leadscrew up, but other than that, its perfect. I had a buddy make me a thick bracket to mount my router to, and thats mounted on a cross slide I also got from ebay. The hard part about all of it was getting it all aligned and perfect. The headstock I bought had a V-belt pully on it, so I used an old motor from my wood lathe and used some 80/20 to build a brace and mount for the motor. All thats left to finish this machine is to finish mounting the stepper motors, which im gonna re-do and use those couplers Gary told me about, and enclose it. Hopefully I can get it done and try to run it in the next week or two.

Joe

 

[Dave38]

If you don't mind a little shipping time, I bought mine off of ebay from this seller (in China) cant beat the price.http://www.ebay.com/itm/120931952335
I bought extra incase they fail and still saved money compared to buying from cataloge companies.
Dave

 

[Mc2]

Well this is the best attempt at a cnc lathe I have seen on here for a while. Other than the couplers the only issue that I saw was the stepper motors. Do you already have a stepper controller? I notice that they are not standard 4 wire bi-polar motors.

Jim.

 

[snipershot]

Well this is the best attempt at a cnc lathe I have seen on here for a while. Other than the couplers the only issue that I saw was the stepper motors. Do you already have a stepper controller? I notice that they are not standard 4 wire bi-polar motors.

Jim.

Thanks Jim. I took your advice when I was asking about how to go about building this a year ago or so. I dont know if you remember me bugging you. lol. I bought a cnc kit from ebay and if all goes well, and I figure out how to run it, Im gonna upgrade to a gecko controller and whatever stepper motor you tell me to get. lol.

Joe

 

[snipershot]

Well, I finally got the enclosure finished and my new flexible couplings came in, so now its time to get the motors turning.

Joe

 

[snipershot]

I got the motors wired, but im not able to move them. Still some bugs to work out. Lol.

Joe