All Gave Some,
Some Gave All.
My computer configuration and software used:
Gigabyte GA-990XA-UD3 Motherboard, AMD FX 6-core Processor Black Edition, 32 Gig DDR 3 Ram, Gigabyte HD 6450 Video Card with 1 Gig DDR 3 ram, Windows 10
Designer 2.007, Designer 3.102, Pattern Editor, Centerline, Conforming Vectors, 2d Tools, 3d Tools, DXF Importer, STL Importer and Rotary Jig.
I am sorry but this was a thread I started on the senior's member forum last year to see if any senior members might want to experiment with this drive rail idea. I did not want, at the time, to post this on the open forum. So far, Steve is the only one who has taken on the experiment. The following is the original post:
CW Rotary Jig Direct Drive Rail
I have experimented quite a bit trying to find out why calibration of the CW rotary jig is so dependent on head pressure. I have put rails under the jig. I have added other pulleys. I have driven just the belt on the wheel and so on. My conclusion is that the toothed belt rolling on the smooth idler pulleys is where it goes wrong. Differing amounts of head pressure cause differing amounts of distortion to the belt as the teeth are pressed against the smooth idler pulleys. If the idler pulleys were sprockets instead of smooth pulleys, I think it would be better. It is a very sensitive thing where small errors really add up.
In any case, I will show you what does work. I bought some 72 tooth HTD 3M 216 belts to fit right on the drive wheel. I got 10 mm wide ones as two fit across the wheel. I took off all of the pulleys and put a simple wooden rail under the drive wheel. I added a thin strip of grip tape around the two belts. The resulting setup does not have the calibration issues.This was just an experiment for me since I use my own rotary jig. I just thought someone might want to give this setup a try.
Last edited by bergerud; 04-21-2016 at 12:18 PM. Reason: Fixed pictures
I for one would like to know more, the pics do not show up for some reason.
This is a copy of my last post on the Senior Members Forum about the modifications
I still haven't received the belts from AliExpress so I just went with 2 layers of non-skid tape on the geared wheel. Everything seems to be working great. My first project since the modifications was the candle holders and I posted them on the regular forum. They were both about 6 hour carves and they carved perfectly. The rail was made as thin as possible so the end plate was very close or actually touching the alignment plate after compression. On my machine it turned out to be 1" exactly. Anything less will cause the rail to slip on the belts. The shim on the other end ended up to be 5/64" to make the jig level. It was made out of hard maple but hasn't been glued on the jig yet. The shoe was made out of hard Maple also. I traced your outline so it could be made it into a pattern. It could then be pushed to the bottom of a 3/4" board so it didn't have to be planed to 1/4" thick. This also made the use of a sled unnecessary. After carving, the shoe was too wide to slip through the space between the belts without splitting it in half and sliding the two pieces back together under the sliding plate lock. It still worked great though.
I can't thank you enough for making the jig truly functional.
After removing all belts, idler pulleys and bearings, the jig actually rests on the alignment plate on the left and the sliding plate on the right. The shim refers to the spacer between the sliding end plate on the jig and the sliding plate on the machine and levels the jig. The shoe refers to a spacer Bergerud made to slide under the sliding plate lock to keep the sliding plate from flexing and rubbing on the belt. I used a small wedge on a couple of test runs and it worked fine.
Last edited by SteveNelson46; 04-21-2016 at 11:24 AM.
Steve
Steve, I really like your candle holders. The minor issues that I've had with the rotary jig have prevented me from tackling a project that extensive. Always had difficulty in getting the end of the carve to meet. Always have about a sixteenth of an inch uncarved. Somewhat awkward when carving bar-tread tractor tires.
Like Normrichards I would like to see the modifications to upgrade my fixture also. Dan has designed some fabulous fixtures to assist the rest of us. If you would please post the pictures, I would make the modifications to my rotary. Thanks to Steve & Dan for their work.
Jerry
Having fun with my CW now!
C Machine spring of 2013, CarveTight, Rotary, designer 3.102, probe/PE,
vector 2d, 3d advanced, conforming vectors, STL. Photo Explosion 4.
HF 2hp dust collector. Headquartered in West-Central IL.
I fixed the pictures. (Copy and paste did not work before.)
Last edited by bergerud; 04-21-2016 at 12:29 PM. Reason: sp
There really isn't much to take a picture of that Dan hasn't already done. The only thing that I changed was to use 2 layers of non-skid tape instead of a belt that fits tightly around the geared wheel and one layer of non-skid tape. If you are willing to sacrifice your existing belt you can cut it to fit around the geared wheel and just use one layer of non-skid tape. Just make sure the seams are on the opposite sides of the wheel. I will go out to my shop and take some pictures of the jig in the machine. It may help.
The geared wheel needs to make 3 full revolutions for calibration and only one revolution for carving. So the calibration rail needs to be about 36" long and the carving rail only needs to be about 14". Both rails are exactly the same except for the length. You could use the calibration rail for carving. It just sticks out of the machine.
After calibrating the jig the first time successive calibrations are not necessary. I did it about 10 times because I just couldn't believe it would be that accurate. But it was. Even after turning the machine off and removing the jig between each calibration test.
The modifications also fixed the incomplete carving revolution problem.
Last edited by SteveNelson46; 04-21-2016 at 01:10 PM.
Steve
I saw that but wasn't sure that was what you were talking about. That puts us back to the old home made jig I just put in the firewood pile. The biggest problem I see is that it reverses everything.
Clint
Clint,
I'm not quite sure of what you are referring to. The modifications only amount to removing everything on the jig that moves except for the geared wheel, adding some non-skid tape, adding a shim under the jig's sliding end plate, adding a spacer under the sliding plate lock and, of course, the rail.
Last edited by SteveNelson46; 04-21-2016 at 03:21 PM.
Steve
Here is a picture of the jig, with the modifications, installed in the machine. The left end of the jig is on the squaring plate and the inside edge of the jig is flush with the inside edge of the squaring plate. The rail is against the squaring plate and against the inside left end of the jig. The shim is sandwiched between the top of the sliding plate and the bottom of the sliding end of the jig. The inside face of the jig is also flush with the inside edge of the sliding plate but it's hard to see because the shim is 3/4" wide. It was intentionally left that way so it would be easy to grasp and adjust. The shim was also notched to fit a little deeper around the mounting screws of the sliding plate lock (not shown). The shoe that slides under the sliding plate lock is also not shown.
Notice the small amount of space between the inside left end of the jig and the geared wheel. This was accomplished by adding a washer between the end plate of the jig and the geared wheel bearing. Also, while the wheel was off, I made the counter-sinks for the mount screws on the inside face of the wheel a little deeper so the heads of the screws don't rub on the inside face of the jig. This was another modification by Bergerud awhile back.
All of the modifications shouldn't take more than one to two hours and if you are willing to spend the time to make them I think you will be amazed at the difference in performance of the jig.
Last edited by SteveNelson46; 04-21-2016 at 05:14 PM.
Steve