# Tech Help on Drive



## balmoralboy (May 22, 2004)

Hi,

I have been having problems with the plastic gears and belts on my Husqvarna Bio-clip deck, so I took them off and replaced them with American standard HTD belts and sprockets with taper-lock bushings. 

I need the HTD cogged belts because the deck is a timed deck.

I selected the sprockets and belts based on the center distance so that the theoretical belt length is within 4 thou of the actual belt length. All sprockets are the same pitch and number of teeth, so all spindles should rotate together.

When I installed them this afternoon I found a curious thing. The left spindle has the belt snug, while the right spindle has some slack, not enough to jump a cog, but still slack. When I rotate the centre spindle, the left blade stays aligned, while the right one gains on the centre one, until the belts clash. This requires that the right spindle gains about 10 minutes (out of 60 per revolution)or 10 to 12 cogs over eight or ten revolutions. When I drove the assembly with the right spindle, there is no gain or loss. Unfortunately, the tractor drives it with the centre spindle.

DOES ANYBODY UNDERSTAND THIS????????

Can you explain what is happening?

At this point, I see only one serious option - Take a quarter of an inch off each end of the right blade. Then shift the right spindle over enough to tighten the belt without having the blade hit the deck wall. Hopefully, when the belt is tight I won't have the problem!!

I hope there's a power transmission guru on here who can explain this to me. Thanks to all of you for thinking about it.


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## memmurphy (Sep 18, 2003)

I think you may have just created a new law of mechanics! :lmao: 

That just does not sound logical without jumping cogs or the gear or blade sliding on the shaft. Just for fun, could you exchange positions of the center and right cog gear to see if that changes anything? I wonder if you run them in reverse rotation the problem would move to the left side? Maybe the center and left is loosing 10 minutes instead? :winky: 

Lot of help I am. It would seem that the belt teeth have to be working their way over at least one of the cog gear's cogs.

Mark


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## balmoralboy (May 22, 2004)

Thanks Mark,

It makes no sense, does it. I did a check count on the number of pitches on the gears, but I didn't do any reversing of gears yet. I guess the next step is to trade the left and right sprockets. I can't trade the centre ones because I got them Tig'd together.

The other job for this morning is to get every last bit of room on the spindle mounting to get the belt as tight as possible.

Jim


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