Derek, visited your web site d3cnc.com. Are the videos operational. Can't seem to open them for viewing. Any estimate when you'll have the gecko's installation complete and comparison info available?
Regards, Doug
As for steppers vs. servos. I have a Tormach PCNC and am VERY happy with it. It has steppers and I've never had any issues whatsoever with them. Servos, in my opinion, are required if you are doing hardcore production. For what I do (and what most small shops and home machinists do), I think servos are an unnecessary complication just to get fast rapids. Remember, on a lathe of this size, you may be cutting at a whopping 2-10 inches/min. rapids of 60-100 inches/min won't slow you down too much. I've got a Gecko coming tomorrow so I can compare the speed of it to the Xylotex -- I've read they increase the high-end speed a lot becuase of the current/voltage you can push through them -- and the switch from microstepping to full stepping at higher speeds.
BTW: The one thing people might have trouble with in converting this lathe is turning the ends of the ball screws. If you are going to do this yourself, buy the lathe but don't take it apart. Turn the ends of the ball screws FIRST and then take your lathe apart. Make sure you have the bearings in stock too so you can test fit them onto the screw.
Derek
Derek, visited your web site d3cnc.com. Are the videos operational. Can't seem to open them for viewing. Any estimate when you'll have the gecko's installation complete and comparison info available?
Regards, Doug
Sorry, no, the videos are not operational. It is more of a rough template of a website right now. When I'm at home on the weekends or at night, I don't have any machines so am getting the website content and design complete.
The preliminary test I did with a Gecko was quite the "WOW" moment! Remember, I was getting 60 IPM with the Xylotex -- 70 was causing it to stall. All the tests were on the X axis.
A little background on the current seutp. I don't have a proper power supply for the Gecko and the steppers. It is 27 volts. I set the current at 2 amps on the Gecko because I'm not sure how much my current power supply can handle. Now, I do have a 36 volt 8.8 amp power supply on the way and these steppers will take 4 amps each so... I think I can get more upper end torque and faster speeds.
I started the Gecko at 100 IPM just to try it, which worked great. Then I figured, what the heck, I'll try more. 150 IPM this time. Okay, if it was this easy, how about more. 200 IPM worked great, too. This thing is FAAAASSSTTT. The issue, though is that at 200 IPM, I gave the slide some pressure with my hand and could stall the motors. I need to do more tests to see where the point is that this machine can move fast but still has the torque to keep going. Maybe steppers with more torque. I have one that is approx. 370 oz/in instead of the 270 I have in there now -- plus the new power supply on the way. I'll let you know.
Derek
If you are still using the Zylotex 269 Oz steppers, then they need 60V for best speed, and 2.8A for best torque. If you are setting the Gecko at 2A, then you are only getting 2/3 of the torque available.
You would get faster rapids from the Geckos with the Keling 48V 7.3A PS. This is enough amps to power FOUR 269S.
CR.
Derek, just orderd a G602 today. Looking forward to your drawings update and mods.
I just finished setting up my 10x22 lathe this weekend. Been playing with it to learn the features. I would also like to see a set of drawing for your conversion. Right now I have a step motor mounted on the end of the bed and a timing belt to the end of the lead screw. I made an adapter that threads onto the end of the screw and mounts the pulley. Works fine but the backlash is excessive with the split nut on the slide.
I am making a plate that will mount to the front of the cross slide and will power it with a belt and pulley. I just need to figure out how to mount the pulley as the end of the screw is not very long.
I was wanting to keep things as stock as possible for now so I can learn just what this thing can do. I expect that some point down the road I will want to ditch the drive gears and stock lead screw and go with ball screws and a more finished design for CNC. I still need to set up the encoder for the spindle so I can synchonize moves for threading. If I can get that working like I want, then the X and Z axis will be next.
Thanks for sharing.
Ron
I got this power supply mainly because I plan on using different steppers. The two I've found are 1.9V @ about 4 amps. I'm experimenting with 270oz/in steppers and 370 oz/in steppers. Both are 1.9V.
If current=torque then that's what I need most -- I've got PLENTY of speed, but more is better
I think you'll like it. I was impressed. We had the tiny MicroMark lathe in house and a huge lathe in house. There is little comparison between the baby lathe and this one. Though, a stock variable speed spindle would have been nice!
Once I've completed the updates, etc. I'll be posting more information, drawings, etc. on my conversion. It was fairly straight forward to do a conversion for a hobby machine... it is an entirely different thing to make a machine I can sell. Just sourcing all the right components is a task in and of itself. I was going to draw this in Alibre CAD (because it is free) but after putting about 5 parts in an assembly, it wouldn't let me move on unless I paid them... so that's out.
If you program the machine properly, this might not even matter. Most software, unless you tell it otherwise, will only cut toward the spindle like a "normal" lathe operation would. Ball screws will let your machine move much faster because there is a lot less friction on the screw and thre are fewer leads per inch (5 for mine).
I finally made a video!
The Z rapids are 150 ipm.
http://www.d3cnc.com/shop/custom.aspx?recid=6
Also, you can see some of the modifications I've done in the picture attached to this post.
Notice:
- The X screw is covered with a tube and slide
- The X stepper & spider is covered with sheet metal
Nice video. Looks to run smoooooth.
I read through this thread and maybe I missed it, but what are you using to sync the spindle to the steppers? To do threading, you need some kind of index and signal from the spindle so the software knows where things are.
I have encoders that I use and they seem to work fine but I have not figured out how I want to mount one to my 10x22 lathe. I still have a lot of other things to do first but this is on the list. My first thought is to use timing pulleys and mount the encoder below the spindle. This allows things to stay under the covers and not get in the way of the gears. If I do what you've done, I can remove all of the gears and use that space. I could even us the gears to drive the encoder but I'd be a little worried about backlash. I'll just have to see.
Thanks for the info and great job so far.
Ron
I use the C3 - Index Pulse Card from cnc4pc.com for $23 on their site. I was having trouble with it at first but that was because the hole in my disk was too small.
I just took the pullys off the back of the spindle and put a disk there. I didn't want it to be in the way of the chips, etc. on the spindle. It is small enough that it doesn't interfere with belt changes. I used a piece of .030 styrene.
I thought about an encoder but this was so cheap and easy...
Derek, what lathe cam software are you using? My 10x22 will be delivered Thursday. Also Enco has the PhaseII QCTP on sale for $89 with free shipping, code WB8JUP. Just ordered one.
The QCTP I got is actually model # 505-2172 which is a -200 series that holds larger tools (5/8" instead of 1/2"). All I did to mount it was to make a thick aluminum block, tap a hole in the middle for the threaded rod that came with the Phase II and drill two holes to line up with the threaded holes on the cross-slide that hold the taper. Basically, I removed everything -- who needs a taper with a CNC lathe?
Warning, sales pitch: I'm using Dolphin CAD/CAM Lathe. I have worked out a reseller deal with them and will be selling it on my site when it opens. Download the demo and take a look http://www.d3cnc.com/shop/item.aspx?itemid=17. Make sure you go through my walkthrough: http://www.d3cnc.com/shop/custom.aspx?recid=8. The software is confusing at first. The HUGE advantage it has over all the others is that it is 1/2 the cost of the competition (call me, I can hook you up if you decide to buy).
On the other hand, if you have the money, check out Visual Turn from MecSoft (quirky, but easy to understand and use) for about $1,200 and OneCNC which I have not used, but have heard good things about (approx. $2,000). I chose to purchase and now resell because I needed something I could afford to make qty. 1-10 parts and not for production.
Thanks, reason I went with the AXA is that I already have lots of tooling for AXA QCTP on my larger Clausing 1300 lathe. As for sale pitch, will keep you in mind when ready for the lathe cam. The video was great.
Hey Derek,
This is awesome. I got the G0602 about 4 months ago and I was just starting to look around to find out about converting to CNC when I ran into your thread here - looks really nice what you've done.
Have you done anything with the motor to make it variable speed or are you still running the stock motor via the belt drive arrangement?
Are you planning on selling conversion kits or only the complete lathes? If the former any idea on pricing for conversion kits yet? I'd like to weigh options before buying parts if there is a viable packaged solution.
Thanks!
Originally Posted by derekbackus
"BTW: The one thing people might have trouble with in converting this lathe is turning the ends of the ball screws. If you are going to do this yourself, buy the lathe but don't take it apart. Turn the ends of the ball screws FIRST and then take your lathe apart. Make sure you have the bearings in stock too so you can test fit them onto the screw.
Derek"
When I converted my mill to CNC, I used a 2" belt sander to grind off the hard surface then put in lathe and turned down to dia. with carbide insert. Finished with HSS. Turning and threading no problem once hard surface removed.
G0602 arrived today. Starting CNC conversion soon.
Thank you!
No, I haven't done anything with the motor yet. I'm not sure how important it is to have a variable speed motor... I don't mind changing the belts. But, if I did, I'd probably look at http://www.cnc4pc.com/Store/osc/prod...roducts_id=155 because it is cheap and easy.
I think there is interest so I may sell a kit or, at minimum, the metal bits. I originally didn't plan on making a kit... When I make the initial parts, I'll probably make 5 or 10 at a time so I have them in stock and can sell kits or do the conversion. I've designed it to be VERY easy to convert. There is no modifications to the original lathe any more except to countersink a single existing hole for the X slide. As for the electronics, there is some work -- for example, re-wire the e-stop.
I got the electronics box designed and am almost done putting it together. After that, I'm going to get a kit from caswellplating.com so I can anodize the parts. I'm thinking purple or blue... any opinions? Maybe I could offer a choice of colors!
Here's another video. This is tooling board @ 10 ipm Feed, 210 ipm rapids. I can get 300 ipm rapids, but Mach 3 has trouble with my computer sending that much information to two steppers at once so it is set as fast as it can go for the current output settings. So, I guess I'll have to live with 210 ipm rapids for now!
Turning the outside of a pipe: http://www.d3cnc.com/shop/custom.aspx?recid=10