n00b question about a RAGB

[A.Baker]

So, I can find them all day. And I don't mind paying a bit. However, I cannot seem to find one with much more than an 1800 rpm rating. Torque breaks things more than rpms. My thoughts are, that if a RAGB can handle 32 HP than higher rpms shouldn't destroy it. So, this is what I'm looking at......


http://www.surpluscenter.com/Power-...1-1-32-HP-RA-GEARBOX-BOTH-KEYED-13-1423-K.axd



Any thoughts?

 

[itsid]

higher RPM may destroy this RAGB even on lower HP ...

Think about it this way: the ball bearings supporting the in- and output shaft have a certain rpm rating (mainly a reason of heat dissipation) , those might fail on higher rpms,
no matter what torque is applied or not, which might cause a leak, running the gear box without oil and it'll fail too.

Just a thought.

'sid

 

[A.Baker]

higher RPM may destroy this RAGB even on lower HP ...

Think about it this way: the ball bearings supporting the in- and output shaft have a certain rpm rating (mainly a reason of heat dissipation) , those might fail on higher rpms,
no matter what torque is applied or not, which might cause a leak, running the gear box without oil and it'll fail too.

Just a thought.

'sid

I thought about that. But I see people using snow blower gearboxes and I can't imagine those being rated any higher. BUT, point taken. So, is there any recommendations for a place to buy a "proper" one for a go kart application?

 

[itsid]

RAGB on a go kart...
I've seen that on a steering shaft, but I'm afraid you want to mount it to your engine for some reason...

No, I'm sorry, I have no idea;
the only thing I would think of is reducing your rpms befor getting to the gear box (a 2:1 wet clutch for example) that would double the torque but that shouldn't be an issue with any engine below 16HP

'sid

 

[A.Baker]

RAGB on a go kart...
I've seen that on a steering shaft, but I'm afraid you want to mount it to your engine for some reason...

No, I'm sorry, I have no idea;
the only thing I would think of is reducing your rpms befor getting to the gear box (a 2:1 wet clutch for example) that would double the torque but that shouldn't be an issue with any engine below 16HP

'sid

So, for instance, what would the guys building race mowers with 20+ horse engines use?

 

[mckutzy]

I think it is also meant for use with an electric motor for a big machine that why the rpm's are low.

Here is another choice though, a little ways down. This look pretty good for what is is, id almost buy one if it were close and I had cash.

http://www.surpluscenter.com/Power-...-001-PEERLESS-RA-GEARBOX-794335-13-1514-A.axd

 

[OzFab]

Hang on, it seems you're all assuming to run the RAGB at engine speed, what if it runs at axle speed which is, give or take, 6 times slower so, more torque (which it can obviously handle) but lower RPM...

With 6:1 gearing, an engine running at 6000rpm will only be 1000rpm at the axle, well inside the RAGBs tolerances...

 

[itsid]

So, for instance, what would the guys building race mowers with 20+ horse engines use?

well.. the guys here on the forum use the gearboxes that came with the mower mostly.

something like this:


but take a look around, to see for yourself

'sid

 

[landuse]

well.. the guys here on the forum use the gearboxes that came with the mower mostly.

something like this:
View attachment 42482

but take a look around, to see for yourself

'sid

AFAIK, the Peerless 700 is a popular choice. Race prepped of course....

 

[fowler]

Yea as Fabroman said

Run the ragb as the final drive

 

[A.Baker]

Well for an insight of why I'm looking into this at all, is because I have a spare craftsman riding mower. 20.5 HP everything works except it snaps belts. And I have a 2 sweater go kart frame. I've built cars and trucks but I'm new to the small engine/drive train world and its quite a bit different from what I've discovered.

So I was planing on running it straight off the engine crank. I really don't know how to run it as a final drive. However, I'm willing to learn.

 

[fowler]

The final drive is the final peice in the drive chain

Ie diff
Or gear reduction in Hubs of powerful freight trucks


So really it wouldn't be the final drive
But u would run the ragb at a reduction from the engne
Them work out the ragb reduction and take it into account
when selecting the ratio from the ragb to the axle

So run the ragb like a jack shaft

U can convert the engine to horizontal shaft by rotating the carb and modifying the oil slinger
But if u are willing to pay for a ragb I'd go that way

 

[zbuck]

Go to heymow.com, I am sure they can help you out.

 

[A.Baker]

I do have the lawn mower read end. What ratio are they usually? Is the low gearing only due to the engine shaft pully to rear axle pully ratio?

 

[OzFab]

Is the low gearing only due to the engine shaft pully to rear axle pully ratio?

It's a combination of things: The unit itself has internal gearing (usually in the ballpark of 11:1), add to that the gearing between the engine & axle assy (around 2 or 3:1) & you end up with compound gearing in the vicinity of 25:1.

By replacing the axle pulley with a much smaller one & the engine pulley with a slightly larger one, you reverse the engine to axle ratio &, therefore, reduce the final ratio.

But, here's the tricky part: you need to get a clutch in there somewhere...

 

[A.Baker]

It's a combination of things: The unit itself has internal gearing (usually in the ballpark of 11:1), add to that the gearing between the engine & axle assy (around 2 or 3:1) & you end up with compound gearing in the vicinity of 25:1.

By replacing the axle pulley with a much smaller one & the engine pulley with a slightly larger one, you reverse the engine to axle ratio &, therefore, reduce the final ratio.

But, here's the tricky part: you need to get a clutch in there somewhere...

Which is why I figured a ragb would be the best route. I'll figure it out I guess. Or just go with plan B which is yet to be determined.

So how does an 11:1 ratio stack up again st typical gearing in these things? Normal ?

 

[OzFab]

There's no such thing as "typical gearing", it varies from kart to kart depending on size, weight, tyre size, engine output & a whole bunch of other variables but, 11:1 is really low; a small yard kart with a 6hp engine & 15" tyres would have around 6:1 gearing...

FWIW, I have plans to use a vert engine with a riding mower transaxle & a belt tensioner clutch; if you look at a typical riding mower, the clutch mechanism isn't that complicated but, does require pedal operation...

 

[A.Baker]

There's no such thing as "typical gearing", it varies from kart to kart depending on size, weight, tyre size, engine output & a whole bunch of other variables but, 11:1 is really low; a small yard kart with a 6hp engine & 15" tyres would have around 6:1 gearing...

FWIW, I have plans to use a vert engine with a riding mower transaxle & a belt tensioner clutch; if you look at a typical riding mower, the clutch mechanism isn't that complicated but, does require pedal operation...

Will it be clutch and shift or will it stop like a mower before you shift? I thin,k this stuff is cool. Like I said I'm new to this. In a car, for instance, typical gearing would be between 3.27 to 3.73. I figured there would be a common ratio.

 

[fowler]

That's just the diff ratio though

A car is a good example

Every car will have a differant ratio

A car may be 3.2 to 3.7 but a 4x4 may be 4.3

 

[Doc Sprocket]

Go to heymow.com, I am sure they can help you out.

Go and sandbag, but beware of posting. The are VERY serious about their sport, and have a tendency to chew up and spit out anyone NOT building a legit racer for sanctioned racing. As a rule, they HATE "BYB's" (Back Yard Bashers).

As for what the racers use- some use a lawn tractor transaxle, some use a 700 transmission, and some use actual RAGB's. A lot of it depends on the race class they are in.

I do not know what make/model RAGB's they use. I didn't pay any attention to that, as I'm using a Peerless 700 (race-prepped) on mine.