Drill motor clutch slippage - HELP??!!

We have discovered that the drill motor transmission will slip even when we have the transmission turned to “drill” (past 15) as far as we can tell.

We have the drill motors reveresed from side to side in our drive train (left side motors run one way, right side run the opposite in order to move forward).

This means that we can turn easily one direction (with the drills driving in forward?) and we slip the clutch when turning in the other direction. Help?

HELP!

Thank you!

-Joseph Vanderway
Coach, Team 599
RoboDox

Just put a plastic tie or something (practically anything will work) tightly around the transmission behind the white clutch ring.

*Originally posted by Iain *
**Just put a plastic tie or something (practically anything will work) tightly around the transmission behind the white clutch ring. **

You see, it’s not the shifting part that’s slipping, it’s the output clutch: The black thing with the numbers on it. Thanks for the attempt, though.

We still need help! One solution we see is opening up the clutch assembly and replacing the springs with something solid. But we’re not sure if this will work for the specific problem, and are extremely nervous about opening it up considering the possiblilty of damage (we don’t have extras). Has anyone done it successfully? Are there other possibilities?

:ahh:

Thanks, all.

*Originally posted by Mr. Van *
**We have discovered that the drill motor transmission will slip even when we have the transmission turned to “drill” (past 15) as far as we can tell.

We have the drill motors reveresed from side to side in our drive train (left side motors run one way, right side run the opposite in order to move forward).

This means that we can turn easily one direction (with the drills driving in forward?) and we slip the clutch when turning in the other direction. Help?

HELP!

Thank you!

-Joseph Vanderway
Coach, Team 599
RoboDox **

Dave Lavery posted a Powerpoint presentation in the Chief Delphi White Papers on how to take apart the drill motor transmissions. It includes a section on the clutch.

See
http://www.chiefdelphi.com/forums/papers.php?s=&action=single&paperid=150

i can’t find this anywhere in the rules that are against this but this happened to us. We tested this with a transmission that we broke earlier on, and our slipping was no more. We welded the clutch plates together. We haven’t done it to our 2 transmissions that are on the robot yet just in case it was against the rules. The way i figure it, it teams are allowed to put in things to lock the transmission into gear then this is allowed

our drill motor has this little clicking noise every once in while. especially when you turn. we can’t firgure out what it is. i believe it is the clutch. i think it is common among all teams, also.

we have the clutch ring turned all the way to the drill bit marking and we have yet to have the clutches slip on us… and we have gone to full stall on the motors, you may want to check that the drills are actually in drill mode.

We had the same problem. All you need is a cable tie (or zip tie, depending on what you call it). Get a thick one and it holds the clutch in place. As for the clicking, we found that just marinating the motor (or so it seems) in WD-40 works.

we had the same problem but we found that the little ring that you use dosen’t always mean that it is in drill or 15 on one of ours it moves all the way back to one before it is locked you might want to try to just keep turning it

We are also having clutch slipage problems.

Background: 4WD robot, using the 2 drill motors in the low gear (126:1 i think) with no other reduction and using the 2 chiaphuas for the other wheels. We originally fabricated a spacer that we put between the clutch ring and the blue plastic drill nose that prevented the clutch from slipping. It worked great until we ended up breaking two plastic casings because the clutch still wanted to slip in high torque situations and the plastic gave way axially. Then we just threw on the nose with the spring instead (drill mode) and it constantly slips now!

Possible Solution: The publication on the drill transmissions suggests to braze the clutch and clutch ring together. We originally didn’t do this because we thought it would cause the blue nose to just twist off in high torque situations (the same way you take it off by hand). This would prevent the clutch ring from wanting to slip and our plastic casing from breaking that way though.

Question (finally): I saw how one group on this topic welded the two together and has not had a problem. . . what type of gear ratio are you using and what kind of torque is it handling? As for everyone else. . . any other suggestions?! This is really hanging us up. Thanks!

The way the spring work is the more you turn on the dial toward “drill”, the harder it press on the spring, and the harder the spring press onto the little metal balls under it.

So, one good way to lock the clutch in gear is to take the spring out, and replace with a solid ring the length of spring when compressed the most. Then the metal balls will be flush with the holes, and grab onto the ring gear with little notch completely and prevent it from slipping.

The other way is to take away the dial completely, and the metal balls as well, and tap the hole, and put set screws in instead.

Suneet,
You never mentioned whether you disassembled the clutch housing to remove the pins so I am going to assume you did just that. In all likelihood you have the clutch ring assembled incorrectly and therefore even though the outside ring is pointed at the locked (drill) position the clutch is at another spot. Open the transmission and check your orientation again and reassemble. Make sure that the clutch assy is engaged with the transmission housing correctly before rotating into the locking position. (as I remember there is only one way to correctly engage the clutch parts.)
If you have never opened the transmission then there is a possibility that you have received a defective clutch.

Thanks for everyone’s suggestions, today the clouds finally parted and I fixed the slipping problem.

For those interested I didn’t realize that the spring loaded pins that the black nose holds down actually prevent the clutch from slipping. . . I didn’t see the need for the black nose, didn’t have it on, and even though the spring was torqued all the way down, the clutch was still allowed to slip. Lack of investigation on my part I guess. Anywho, I was determinied not to change my mount set-up and just used set-screws to keep the spring loaded pins in place, where they prevent the clutch from slipping. Seems to work nicely but haven’t truly beat it up yet.

Thanks again!

*Originally posted by Ken L *
**The way the spring work is the more you turn on the dial toward “drill”, the harder it press on the spring, and the harder the spring press onto the little metal balls under it.

The other way is to take away the dial completely, and the metal balls as well, and tap the hole, and put set screws in instead. **

Are the set screws the same ones (M6 x 1.0 x 12 mm length) as last year, or are you telling us that it could be done the same as last year?

Joe P