7.2 upgrade, now 1 X moves faster than other...

[harryball]

I installed my upgrade (wow, it arrived much quicker than expected) and used the information online including Franks installation guide. note, I didn't get new ribbon cables but I did get everything else on his list. http://www.talkshopbot.com/forum/messages/7/23261.html?1186921040


I have the motors installed as indicated by the X1, X2 or Y markings. The drivers are set on F / 8 and all the dip switches are set to the left when facing in the control panel. I set my unit values for X and Y from 1273.2395 to 2482.8171 and was careful not to mix up any cables by marking them all before removing anything.

On initial power up things seemed very good, I nudged it around using the keyboard and it seemed good. Then I began running down the length of the table and the gantry jumped its track! To make a long story short, I dropped both X motors off the racks and when I'm running them one motor is running faster than the other.

I double checked all my numbers but I don't see any settings that treat the X motors differently. I also verified all the drivers switches are set the same. It is very obvious they are running at different speeds when running at jogging speeds with the keyboard. When running slower than 2 ips, to be honest, I can't verify if the speed is different and I did make it half way down the table without a problem... I'm not sure what that means.

Ideas of what I should check now?

Robert

[richards]

Robert,
Check the dip switches again. Make sure that all switches are 'firmly' pushed to the correct position. A dip switch that is not firmly pushed to the correct position will sometimes act as if it is in the opposite position. Because the problem seems to be between the two X-axis motors, I'm guessing that a dip switch on one of the stepper controllers is not firmly seated.

Also, did you change the multiplier from 4 to 5 with the VU command?

[harryball]

I switched all the switches to the other position and back, verified my numbers again and yes, I did set the multipliers from 4 to 5. I can't understand what would be causing the X motors to run a different rates.

Robert

[harryball]

I engaged one X motor and moved to 48" and back, then I engaged the second X motor and did the same, the measurements were the same, except for the speed at which they move it seems they are traveling the correct distances.

Robert

[harryball]

I traced the wiring again to make sure, X2 is correct and it is the faster motor. X1 is moving slower.

Robert

[Brady Watson]

Call SB 1st thing in the morning. It sounds like you've done everything correct on your end. Let us know how it goes.

-B

[harryball]

I even double checked to make sure that somehow I didn't get a driver confused with an old one etc... everything is as it should be.

I did go ahead and move my stops or limit switches (whichever was required) and finished all the physical tweaking. I only had to move the X stops on the X=96 end and the Y stop on the Y=48" end.

The only dumb thing I did was re-shrink wrap my connectors and tie everything back up before powering up for test moves... I've now pulled all that back off until I figure it out.

Robert

[richards]

Robert,

Good luck. I've spent the last little while scouring the Oriental Motor web site and the SB3 command manual looking for any clue. Until now, I've never even looked into how the X1 and X2 motors are slaved. The VI command has no provisions (as far as I can tell) to reassign the X-axes indepently (and no way to adjust one axis against the other). I believe that even the cabling between the motors and the drives is furnished by Oriental Motor, so the possibility of miswiring one of the coils is almost non-existant. (If this were a 4g upgrade, my first suggestion would be to verify that both X-axis motors were wired identically - Bipolar Series or half-coil, because that kind of wiring mismatch would cause exactly the kind of problem that you're experiencing.)

Anyway, let us know what you learn from Shopbot.

[ted]

Robert,

As indicated in my note to you. Given all your and Mike's careful diagnostics above, it must be an incorrectly programmed drive. We'll get a new one off to you tomorrow.

-Ted

[richards]

Robert,
Believe it or not, it's fortunate that the gantry jumped its tracks. If the faulty stepper driver (or even a loose or wrong-sized spur gear) had been on the Y-axis, you would never have been able to cut triangles with straight sides or circles that were true circles. In fact, it probably wouldn't hurt to sacrifice a 48 X 48 inch piece of MDF or particle board whenever spur gears, motors or drivers are replaced to verify that everything is working properly. By cutting a large square, a large triangle within the square and a circle within the square and by drilling a hole in the middle of the circle, it would be easy to visually verify that the X-axis motors and the Y-axis motor are working properly. If one of the motors or one of the spur gears or one of the stepper drivers had a problem, the square would not be square; the circle would have an oval shape, and at least one side of the triangle would be bowed. Even slight problems could be detected by by using the simple method of stringing two pencils together, placing one pencil in the hole drilled in the middle of the circle and tracing the edge of the cirle with the other pencil, similar to the way we used to draw large circles back in geometry class.


3696

[harryball]

I believe it must be the X1 drive. I did a little more diagnostics early this morning. I swapped the X1 and Y drive and the problem went with the drive. My X axis is now working perfectly.

The Y axis is curious though... it seems to move below advertised speeds but is accurate when making Moves. Even at a requested 12 ips move rate it clicked off 24" and returned to 0 accurately. For Jogs (JY 24) it moved exactly 12" and indicated it had moved 24".

I'm confident I've isolated the drive as the problem.

I appreciate the great support from Shopbot, I'd not expected to receive an email until later today from anyone, much less from Frank and Ted before midnight. Thanks guys!

Mike, thats a great suggestion, I will definately devise a diagnostics cut that will check everything. Doing so now can only help in the future.

Robert

[harryball]

New driver received and installed, problem solved! I ran my bat house kit file after the upgrade and tuning the bot to all the new numbers and it ran more than 2 MINUTES Faster! Much more than I expected. The best time in the log previous was 18m 43s and it ran in 16m 34s post upgrade.

Thanks for the quick ship and support.

Robert