Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: dfurlano on April 28, 2007, 10:29:21 AM
-
I am interested in buying a tabletop cnc lathe with a linear encoder. I would prefer to buy it as a complete system I really do not have the time to build one myself.
Any suggestions on which to get?
Thanks
Dan.
-
Hi, Dfurlano
Most of the Lathes out there, " I now of " need some conversion or interface work.
I'm sure others will post more info for you.
Just a start Hear, Chip
-
Hi dfurlano, take a look at http://syilamerica.com/. They have a new benchtop lathe that looks very nice, at a very good price of $3499.
Roberto
-
The Syil lathe looks good and has an encoder. I guess the one negative is that I would be one of the first people to own one. I would much more prefer something that I could find others have used so that when I run into issues there is someone else to ask.
-
MDA Precision sells benchtop Wabeco lathes that have been fitted for CNC - not cheap, though.
Mike
-
Hi dfurlano, I know what you mean about being one of the first, but I have decided to do it and have one on order. The lathes have arrived in LA and so hopefully I should get mine in a short time. I talked to Richard Lowe at Sylamerica a number of times and have been very impressed with him. He said the Chinese company that makes the lathe is very dedicated to put out a quality lathe. He has run one and was impressed. I will keep you informed after I play with mine a little and let you know what I think about it.
Robert
-
The Syil lathe, I looked at the pics, not all that impressed. The X axis stepper motor is just hanging out in mid air, and I mean WAY out there, they say about covering the steppers to protect them from "Fritters". I imagine they mean chips, yet the Z axis ballscrew is completely exposed to chips. It can't be running in closed loop, very few do. Steppers look like they might be sized right.
-
Ok DALgie, tell me what you are impressed with? I want a small tabletop system. Every system has issues the question is which ones are worth buying and which are not.
MaxNC seems to have design issues that everyone complains about.
MicroKinetics is a proprietary system that only allows you to use their software.
Most of the Sherline companies do not have encoders on the spindle, although it can be added I am back to trying to figuring out how it gets integrated into the package. Most of the companies don't care or don't know how to get it done. Additionally I have heard they are have a lot of backlash out of the box.
I don't have the time or desire to buy a lathe and convert it myself, I did that with my mill.
After that you are into a $5k system which is way beyond what I want or need.
-
Reberto,
I would really like to hear about your experience with the lathe. Please keep us posted.
Dan.
-
Understand about not having the time to convert a lathe over to CNC control. Maybe then it comes down to improving the thing as you go, make a sheetmetal cover for the ballscrew, remount the X axis motor when you have time, etc. As Dan said, I would also like to hear about your experiences with this lathe, keep us posted please.
DaveA.
-
Roberto,
Did you get your lathe yet?
Dan
-
Dan, the lathe has arrived in town and will be delivered to my house tomorrow. It will probably be a few days to
get it going and check it out.
Bob
-
WooHoo let us know... I wouldn't be able to do anything else till I got it running....
-
Yes, I will be at it as soon as I get it. I installed a subpanel so there is plenty of power available, but it will have to be wired up..,.Then I will have to get familiar with it and see how it goes. I have had the Mach3 program for a month and have written some sample programs, so it will be a matter of learning if they work as well in reality as they do on the computer screen.
-
Well, I have had the lathe a week and after getting it set up in my garage, I finally have been able to play with it. It is very solid, weighs about 450 pounds. It took myself and four friends to lift it on the bench. But having that weight it is very rigid for a benchtop. I got the very first lathe they shipped out and as such they have not had a chance to write a manual for the CNC part. There is a manual for the standard lathe. But, Richard Lowe has been extremely helpful and I have made a number of calls and he has helped me out a lot. To answer the comments of DAlgie, the ball screws are completely covered with metal covers. I think they had them uncovered just to show for the pictures. The x axis stepper does stick out a little but it is not as much as it seems in the pictures. It causes no problems. The appearance of the lathe looks every bit as good as the pictures and seems to be very well made.
One of the things I learned from Richard was that you have to be sure to take off all the packing grease off the ball screws before operating.
Again, Richard sent me a profile for this lathe that he wrote to install in Mach 3. i did a few small cuts on Aluminum and was very impressed with the smoothness of the surface. It has a 1.3 hp motor and so has plenty of power. I tried a .100" cut and it handled it with ease. I haven't tried, but Richard says he has taken .050" cuts in steel, with no problems. I then wrote a small program to cut a hemispherical surface of 1.25 " diameter. It worked well and gave a beautifully smooth hemisphere. When I went to run it again I found a little glitch. On making the fast traverse the Z stepper motor stalled. On checking with Richard he helped me to adjust the velocity and acceleration of the Z axis. It was set a little too high and also he thought I should adjust the Gibs as the Chinese tend to have them pretty tight for shipping. After playing with this a while I found good values for velocity and acceleration that worked well. Then I started checking for accuracy of cuts and found they were off a little. So another call to Richard and he told me I have to tune the stepper motors. ( I am new to this game and didn't realize this). So he helped me. There is a formula in the Mach turn manual that tells you how to calculate the values for z and x. So we calculated and tuned the motors. This gave more accuracy, but not good enough. So you can check the values by putting on a good dial indicator and then do it by trial and error. After Playing around with this awhile I again came up with good values that gave good accuracy. (Generally within .0005 to .001 inches in both the x and z movements over a 1 inch travel.) I think the reason that the calculated value was not as good as it should have been is that we were not sure of the exact value of the pitch of the ball screws.
So I wrote another more complicated program that bores into a 1.1 Inch piece of Al and has a 20 degree taper inside that goes in from x=.902 for about . .350 and then makes several steps going to smaller and smaller diameters. It came out really nice. The surface on the very inner steps was a little rough because I was using a small diameter boring bar and took a little too big of cuts to do the finish.
So, overall I am very pleased with the lathe so far. I found out that this price of $3499 was an introductory price for this first shipment and after that the price will go to $4495. As I use it some more I wrill write in and let you know how it goes.
As an aside I got a call today from a company I had checked in with several months ago on getting a Dynamite lathe. He said it was only $45,000! When I told him I got a new CNC lathe for $3499, he didn't believe me. Of course mine is not nearly as sophisticated as the Dynamite, but I think it will do erverything I want to do.
-
All sounds very nice! As a bit of caution, when you get a quick change tolpost and toolholders, be careful to take the time to learn how the lathe too offsets work on Mach3. It's not that straightforward at first and you can cause a crash if you're not sure how it's set up. A bit more complex than Mach3 mill I'd say, reply back here when you're ready and I can help if needed.
DaveA.
-
OK, Dave, thanks for the offer. I will take you up on it in a couple of days. I just got a series 0 KDK tool post and 5 holders on ebay. This morning I had to modify the top slide to take it, but everything worked out OK. The nice thing about it is that the tool holders will fit the 100 KDK which I have on my big lathe, so I can just switch tool holders from one lathe to the other and just have to adjust the heigth.
Bob
-
Dave or someone, I do need some help. I edited a program that I wrote and when I went back to auto, the display showed just a horizontal line. After playing a little and enlarging I could see a tiny place with some red that I guess are the lines for the cuts made in the program. It is so small it can berarly be seen. It looks like the scale on the screen is about 1/50 of the size it should be. I can't find a way to get the size of the object large enough to see the individual cuts so I can watch he program run to see if it is working ok. Any help would be appreciated.
-
Post the program on here and we can take a look at it. if you click on the graphic display partion of the screen you can then zoom in, use your scroll wheel on the mouse, and also pan the view if needed, try it and you'll see it's very nice to use. I use the "Silverblue" screenset available on here, same controls but a much nicer display.
-
Dave, it is not the program as I have run it several times before. I also have two other programs that used to work and now do the same thing. I know about clicking on the display and zooming in. When I do this the horizonal line (which represents the cylinder to be turned) goes from a line to a cylinder of about 1/16 in diameter! I tried another tack. I had originally programed these programs on a laptop, so I copied the program on a USB memory stick and the put it into the lathe computer and loaded the program from it. At first it showed the same horizontal line, but when I hit the regenerate toolpath button, voila, the screen showed the tool path full size. Why? I don't know. I had tried the regenerate button on the program loaded from the lathe computer and nothing happened.
I guess I will just trash the programs on the lathe computer and reinstall them from the laptop. I plan to always write the programs on the laptop so I have a fall back in case this happens again. I am sure though that there must be a way to change the scale on the screen, but I can't find it.
-
Hi, Bob
Run the Mill a few time's, Load some other files, Then run lathe again.
I've had this happen several time's, Haven't been able to trace it to anything except when edditing G-code Files.
It will sometimes do it in mill with a view screen Error Msg., Wth blank screen.
No real answers Hear, Chip
-
I'll have to admit, the toolpath display is not ALWAYS correct, you can get some quirky stuff there at times, but quite often it is an arc that has the wrong IJ, or direction, etc. If the part you are trying to machine is quite simple then the toolpath display will probably be right, but if it's complex, just trust your code and go with that. On another point, have you tried the wizards yet? These are great for 75% of the parts you might need to machine, you can combine different ones into the same code as well. You'll find the one thing missing is a G71 roughing type canned cycle, this will rough out an arbitrary shape you call out. You can post a DXF into it and it will post out the code for the profile, but it's not much use without some way to rough it out first.
-
Roberto,
Any further updates on your lathe? Still happy with everything? How has it been running?
Thanks
Dan.
-
Dan, I am very pleased with the lathe. I had one very minor problem, the controller would not turn on consistantly. I have to wiggle the switch to turn it on. After a little playing around I found that it was the power on switch. I called Richard at Syilamerica and he has a new switch on the way. I have been doing a lot of playing around to learn the best way to do things as this is my first CNC lathe. I did a lot of checking on the accuracy and playing with the tuning of the motors, but Richard called the company that makes the ball screws and found out the exact TPI of the screw. ( We weren't sure before.) So then we could calculate the number of steps in the tuning. And lo and behold it was exactly the same number I came to by doing a lot of trial and error measurements. That was very comforting. I have turned out a few parts and I am really pleased with the very smooth finish on them. I checked them and found the dimensions were all to within .0005 inches or as close as I could measure them. When I made these parts by hand, it took about 15 minutes to do one operation. The CNC does it in 3min 19 sec. I could push it a little faster but there is no need to do so.
I still do not understand exactly how to set up the tool offsets. I try to follow the instructions as best I can, but it is still not correct. I am leaving for a 2 1/2 week trip to the Ukraine on Sunday and so do not have time to try until I get back. I will contact you then and see if you can help me out.
Thanks, Bob