Unique machine challange

[cabinetcraft]

Well here is a unique project that I am thinking about, converting a quilting machine to cnc. There are a few ones offered on the market but that would be no fun, I would rather build it myself.
Here are the parameters the x-axix is 120" long and the y-axis is 24". There is no z-axis to worry with. Resolution needs to be in the range of 1/100 of an inch. Sounds easy, right? Ok well to be productive it needs to sew at 3 to 4 ips and possibly 4 that's 180 to 240 ipm, with indexing moves above that. The biggest issue I see is inerta, The machine itself is about 35lbs and the y carriage will be another 5 to 12 lbs at least (it has to carry the complete y-axis system). For instance when running into the point of a star the last stitch is the last stitch before direction reversal, there is no radius or room. Been thinking about belt drive on the x-axis as it would be cheap, easy and give the required resolution, probably rack and pinion on the Y as it would be compact. So how does one calcuate how large of a motor will be required? Either stepper or servo. It there acc and dec on steppers? Does Mach3 read ahead and allow you to slow down when necessary?
JUst a bunch of questions and an Idea that I am dying to try, I know its being done, but I wanna do it my self.

thanks guys

[Al_The_Man]

For motor sizing etc, check out the Kollmorgen free graphic sizing, most servo manufacturers supply one, there are many out there.
You may not want to go the 'exotic' route of motion card, but here is a Galil Demo of quilt machine. http://www.galilmc.com/support/motio...t_stitcher.swf
Al.

[Larry Lamb]

I've been following this thread and others at other sites, and I have been wondering, why on earth would you want to convert a computerized quilting machine to a CNC system? Just for the thrill of doing it? Sorry, but I can't see the logic here. I built a CNC quilter using two NEMA 17 steppers and a Peter Norberg controller for both X and Y axis. So far the whole has cost me a sum total of $7.00 for the motors, $78 for the controller, about $30 for flexible braided wire cable of 1.5mm size and a handful of screws. My biggest issue is the Visual Basic software control. The class files that come with the Norberg controller are written in VB6 and I have VB.Net from the VB.net 2008 freeware from MS. I think instead of tearing something down to build something new, you might want to consider building what you want out of inexpensive parts, you may get more pleasure out of it.

[lmlamb]

Cabinetcraft,

What quilting machine do you have, which sewing machine rides on it? As I said earlier, and I probably misread what you said in your post, as it appears that you are wanting to computerize a manual quilting machine. That is exactly what I have done. My wife has a Husqvarna Viking machine on a Grace Quilt machine frame with a 24 inch width. The table is 112 inches long. I am driving the system using two NEMA 17 1.8 degree steppers bipolar. I designed a cable system using 35 pound test polyethylene covered stainless steel fishing wire that I picked up at the local fishing store. It works very well and pulls the carriage very smoothly on the table. I am using Mach3 for the controlling software, set at 1/8 step, 800 steps, with a resolution of .05. It may be possible to get better resolution by changing the pully wheel on the stepper on the x-axis to a smaller wheel. 1/1 would be the best but you know how that goes, you use what you can get and then do the math to change it. How is the project going now?

Larry

[supertechster]

Larry,
I understand tat you did the x (long axis) with wire. Did you use a pulley or wrap ut around the shaft 2-3x?
How did you do the Y?

Thanks1

[lmlamb]

Originally Posted by supertechster Larry, I understand tat you did the x (long axis) with wire. Did you use a pulley or wrap ut around the shaft 2-3x? How did you do the Y? Thanks1

I am using a couple of pulleys that I picked up at Conrad Electronics here in Wiesbaden, Germany, they are 13mm with a 6mm shaft hole, hub with 2 set screws. I wrapped the wire 3 turns on the pulley, so that it won't slide when torque is applied. I also did a setup using 3/8 mxl belt for the X-axis and it works really well also. There is a little bit of stretch to the belt, so I'll be trying a different type of stainless steel cable for 50lb test to see if I can overcome the stretch.