***Tav2 bolt pattern not lining up!!!*** URGENT***

[winchman420]

Is the comet 30 asymmetrical or symmetrical? When I did a mockup of the tab on the engine I did notice that the belt was not quite in line

 

[itsid]

Just to help clear up a point of confusion, symmetrical V/S speed drives usually only have the drive belt running in a straight line when the drive is ~in the middle of its range. When at one end or the other, the belt will look like it's out of alignment when it actually isn't

Its normal, and the belt's are engineered to run that way. As long as you follow the OEM's instructions on how to set up the unit you have, you should be fine. This is for symmetrical V belt drive's only. Asymmetrical belt drive's need to have the vertical pully faces in line with each other, and the belt will run in line at all times.

The belt is straight and inline between the center of the two sheaves on both, the series 30 and the series40 when mounted with an inboard driven.
And that all the time (from low to high gear and everywhere in between)

Both systems are designed, so that the moveable sheave of the driven exactly counteracts the moveable sheave of the driver.
The asymmetric series 30 can achieve that most easily by lining up the two straighter fixed sheaves.
The series 40 is less obvious.
but inboard mounted the movement of the "now inner" moveable sheave -or precisely it's travel- is exactly that of the "outer" moveable sheave of the driver.
so the belt moves towards the engine, but the asame amount on both, driver and driven (thus it remains perfectly straight!)

Or ideally it should...
that's why I'm not a fan wof outboard series40 with a non compensating float for the driven unit.

Is the comet 30 asymmetrical or symmetrical? When I did a mockup of the tab on the engine I did notice that the belt was not quite in line

30 is asymmetrical; easily to identify by the one nearly perfectly vertical inner sheave.

'sid

 

[machinist@large]

The belt is straight and inline between the center of the two sheaves on both, the series 30 and the series40 when mounted with an inboard driven.
And that all the time (from low to high gear and everywhere in between)

Both systems are designed, so that the moveable sheave of the driven exactly counteracts the moveable sheave of the driver.
The asymmetric series 30 can achieve that most easily by lining up the two straighter fixed sheaves.
The series 40 is less obvious.
but inboard mounted the movement of the "now inner" moveable sheave -or precisely it's travel- is exactly that of the "outer" moveable sheave of the driver.
so the belt moves towards the engine, but the asame amount on both, driver and driven (thus it remains perfectly straight!)

Or ideally it should...
that's why I'm not a fan wof outboard series40 with a non compensating float for the driven unit.




30 is asymmetrical; easily to identify by the one nearly perfectly vertical inner sheave.

'sid

Alex, to many people's disbelief, V belt drive's of all designs can accommodate far more misalignment than any chain drive. And I've seen more than one application over the 25 year's in industry (plus another 18 growing up on a small farm) where this type of drive will just plain work.

In a perfect world, should all belt drive's be perfectly aligned? Yes. On the other hand belt drive's are much more forgiving than any chain. I had to quote a replacement for a V/S drive set up about six years ago where the old system was dying of old age. And the pully set up was so far out from ideal I had to ask how many belts they went through a year.

The driver and driven were offset by over ~4 1/2" to 5" with a C/C distance of less than 24". They said they had moved it into that set up because they needed the clearance for what they were now doing.

It ran that way for almost 5 year's on the same belt.

 

[itsid]

They're designed to run the belt perfectly straight.. and the mounting instructions -if followed- will keep it that way.
That's all I said

Yes, the belt can be run with a slight offset,
but any offset will result in premature wear..
since belts for TCs are rather expensive (compared to general automotive v-belts)
that's well possible, but still expensive in the end to run a non perfect belt alignment.
And do not forget we talk about one belt width of offset with maybe 8" distance to compensate said offset.

I don't know what abuse that setup you're talking about has seen in the five years the owners claim it ran with one belt.
But seeing that you can easily fray a belt into uselessness within minutes on a go kart on a less than optimal ratio or setup....
*shrugs*

I say: "as intended by the Mfg" or don't... at least that's a safe bet

'sid

 

[winchman420]

Ok, I got everything re drilled and bolted on. On some instructions it says there is supposed to be a brass bushing that slides on, but mine did not come with one so I assume it doesn't need it? Mine is the 30-75. Also, the belt is tight going on. Is that normal?

---------- Post added at 11:32 AM ---------- Previous post was at 11:10 AM ----------

Besides belt alignment( I'm going to cut down the spacer) does this look right? Or should there be a brass wedding ring? It didn't come with one

 

[itsid]

the brass bushing is ONLY on 3/4" shaft versions of the TAV, not on your 1" shaft version.

yes, remove the spacer and see how much offset you would get;
it looks like you might get away with a simple washer.

'sid

 

[winchman420]

Wow thank you so much you have been very helpful!

 

[machinist@large]

They're designed to run the belt perfectly straight.. and the mounting instructions -if followed- will keep it that way.
That's all I said

Yes, the belt can be run with a slight offset,
but any offset will result in premature wear..
since belts for TCs are rather expensive (compared to general automotive v-belts)
that's well possible, but still expensive in the end to run a non perfect belt alignment.
And do not forget we talk about one belt width of offset with maybe 8" distance to compensate said offset.

I don't know what abuse that setup you're talking about has seen in the five years the owners claim it ran with one belt.
But seeing that you can easily fray a belt into uselessness within minutes on a go kart on a less than optimal ratio or setup....
*shrugs*

I say: "as intended by the Mfg" or don't... at least that's a safe bet

'sid

Have you ever owned a riding lawn mower with a ground tracking/hugging mower deck? I don't know about Europe, but their fairly thick on the ground here in the USA.

And that drive V belt just take's the rolling in three axis constant misalignment in stride. If the technology couldn't handle it, the North American lawn care industry wouldn't exist.

 

[itsid]

I've seen long belts doing the nastiest things (including a 180° flip)
but that doesn't mean that I think it's a good idea for a reliable and "least abusive" go kart setup

Simplified:
Anything non ideal means additional stress and cause additional wear;
additional stress means it's more likely to fail and additional wear means shorter lifetime...
none of that is actually wanted I guess.

'sid

PS you're currently adding a single disc to a diff housing, you're aware of that, aren't you?

 

[winchman420]

me?

 

[itsid]

me?

hehe, no, not you; Pat... (machinist@large)

'sid

 

[geewally]

itsid and machinist@large you are both correct!

thank yous!