Low speed roughness - normal?

[terryp]

After reassembling my HT in Chicago I noticed a slight 'rumbling' at slow speed that I hadn't noticed before. The frequency is close to that of stick shake, but it's much less pronounced. It's more than the gear play that you hear when standing still. It's often rhythmic, like one second of vibration alternating with one second of smooth running. Above a certain speed it seems to go away.

This could just be a product of shipping paranoia - maybe it's always done this and I never noticed. It won't bother me unless it gets worse. I'm just looking for some assurance that it's not an indication of bearing damage due to rough treatment. Has anyone else noticed this?

Practicing Safe Segs in Seattle

[edh]

TerryP-

I've had the same issue off and on, and Doug Field was nice enough to spend time at SegFest looking at mine. The problem (on mine anyway) was a combo of dirty shafts and wheel nuts not tight enough. The rumble is because the hex pattern is driving the wheel some - instead of the cone shaft itself. The hex is desigined as a backup, not the primary drive, the rumble is slight slipping from the hex drive, since it has a loose tolerence for easy wheel removal.

This fixed mine:

1) Clean the drive shaft (not the threaded part) and the mating surfaces on the wheel with rubbing alcohol. Use a rag & qtips to get it all clean. Allow time to dry (5 minutes)

2) Make sure you are using a torque wrench and putting the nut on tight enough - I wasn't. Went to Sears as soon as I got back, and invested in a good qualty torque wrench. Make sure you crank them to 50 N-M.

Seems like minor fixes, and when Doug told me what he was going to do, I thought it would never work. Thought for sure I needed a new gearbox etc. as my rumble was really bad - My Seg also pulled really hard to the left as well, which was corrected too. Anyway these two simple steps fixed it.

I must say, I am also surprised I have not seen these mentioned in a FAQ anywhere, as I would think anyone who removes their wheels for travel would run into this sooner or later.

Hope this helps you

-Ed

[terryp]

Thanks Ed.

I just took off my wheels, and sure enough there was a little crud on the mating surfaces of each. I'll find out tomorrow if it made any difference.

I've always torqued to spec, and didn't have a pulling problem, so this may be something different. Or it might be so minor that it's nothing to worry about. In any case, the cleaning can't hurt.

Practicing Safe Segs in Seattle

[q]

quote:Originally posted by terryp

Thanks Ed.


__snip__

In any case, the cleaning can't hurt.

Practicing Safe Segs in Seattle


//

agreed. at least once/week, i
take off the wheels, pick out
(gently) the pebbles in the
tires, which are then washed,
clean the fenders, and then
reassemble, torquing to spec.

ahh...

kthxbye.

q.

http://www.pcisys.net/~qwhew/segway/jpg_segway_sfest_08312003_sunday_3g.jpg

//

[pam]

Terry, there was originally some locktite on the threads, it's possible that the locktite has affected the read on the torque wrench.
Pam

quote:Originally posted by terryp

Thanks Ed.

I just took off my wheels, and sure enough there was a little crud on the mating surfaces of each. I'll find out tomorrow if it made any difference.

I've always torqued to spec, and didn't have a pulling problem, so this may be something different. Or it might be so minor that it's nothing to worry about. In any case, the cleaning can't hurt.

Practicing Safe Segs in Seattle

[terryp]

Good point Pam, but I'm pretty sure that they're torgued tight enough. I still noticed the slow speed 'rumble' today, but it's faint enough that I don't think it's worth worrying about.

Practicing Safe Segs in Seattle