Not ideal for the helical gears but in our apps acceptable
Edited as the penny has dropped
[Edited on 8/1/11 by ReMan]
im looking for 2 identical gears. around 2-3 inch in diameter and about 1 inch wide. I'm wanting to make a small gear box to change drive
direction.
A bike engine will be mounted backwards so the drive needs to be changed so i have 6 forward gears and not 6 reverse ones. This is going in a mini so
space is tight. One of the gears will be attached to the engine and the second gear will have a sprocket with a chain going to a chain diff.
Any help will be great.
Craig.
Why has the engine got to be installed backwards?
because if i install the other way there is no space for the diff as it will need to go directly behind the engine. only other way i can think is to mount the diff above with a chain going up the two coming down to the drive shafts but this is too complicated and time consuming.
MNR or Quaife reverse box would do it.
You can't use any old gears driven at 11000 rpm with 100 ft/lbsgoing through them
The oil pick up is also at the rear end of most bike egines. Could cause a few problems extending the oil pick up if your not useing a dry sump!
Also the gears wouldent last two minutes without a supply of oil to them.
oil pick up wont be a problem.
The gears will be in a casing with oil.
Just need a source or the gears/where to look.
They need to be able take the abuse from the engine with out chewing each other up.
maybe butcher a scrap gear box,
or
build a small 2 cog offset box (like a 4x4 transfer box with splash lubrication or even a small circulating pump with an oil cooler if heat is a
problem.
HPC Gears are very good for the cogs
Check in the technical section for all manner of info linky
[Edited on 7/1/11 by liam.mccaffrey]
i have an idea don't laugh! mount the diff upside down this will change direction .you will have to change the oil drain to other side of the
diff though. your right wheel will become your left side and your left wheel will become your right.
its an easy fix and save a load of hastle.
[Edited on 7/1/11 by chunky2772]
[Edited on 7/1/11 by chunky2772]
quote:
Originally posted by chunky2772
i have an idea don't laugh! mount the diff upside down this will change direction
Hi
Type 9 5speed 5th gears maybe.
Cheers Matt
"i have an idea don't laugh! mount the diff upside down this will change direction "
yes this would work
Think harder! get a diff turn it upside down with input drive shaft still faceing the same way watch what happens!
Your diff still turns the same direction but you will move backwards i aint jokeing! This is your problem solved you may have to put a little more oil
in the diff and change the drain plug but its a much easyer fix. CAN SOMEONE PLEASE TRY THIS AND BACK MY IDEA UP.
quote:
Originally posted by SPYDER
quote:
Originally posted by chunky2772
i have an idea don't laugh! mount the diff upside down this will change direction
Ha ha ha!
No it won't.
Think about it.
NO A CHAIN DIFF WONT WORK UPSIDE DOWN
Not ideal for the helical gears but in our apps acceptable
Edited as the penny has dropped
[Edited on 8/1/11 by ReMan]
Diff is to be chain driven, wont matter which way up it is, will still turn same way
Look at www.r1manx.com may give some inspiration
Its a CHAIN driven diff.
Go and think about it again.
Geoff
Do you think the penny will drop Geoff
hahaha
if you don't have a pinion, you can't run it upside down.
surely enough people have done successful mini conversions now that you could follow their example and save the faff of making a box?
i assume you'll be using helical rather than spur gears? a car gearbox would be my first choice if i were to be making a box.
quote:
Originally posted by SPYDER
Its a CHAIN driven diff.
Go and think about it again.
Geoff
ha, ha, I love this!
Yes it will still be a chain diff and not a normal diff so mounting upside down wont help.
There are kits etc for doing this like from pro-motive but its 3.5k which i dont have.
Will have a look at some gears from a gearbox. see what i can make lol.
engine longitudinal, sprocket pointing forwards, direct driving a (normal car, with pinion) diff pointing the "wrong way" and turned
upside-down.
This is what we looked at doing on the supercharged Blackbird engined fiat 126 we're building before we went for the current plan:
open chain drives are nasty and I really don't like them! (yes I do say that based on experience! )
[Edited on 8/1/11 by NS Dev]
[ tongueincheek] Could you use a Mobius strip chain? Mounted inside out.
Or put the front wheels on the back.
That would work wouldn't it? [/tongueincheek]
On a serious note, something like this maybe....
Found it HERE
apparently that short a run of chain will overheat in very little time, approx 15 mins according to Muffet eng
quote:
Originally posted by blue2cv
apparently that short a run of chain will overheat in very little time, approx 15 mins according to Muffet eng
ROTFPMSL
quote:
Originally posted by SPYDER
[ tongueincheek] Could you use a Mobius strip chain? Mounted inside out.
That would work wouldn't it? [/tongueincheek]
quote:
Originally posted by T66
quote:
Originally posted by blue2cv
apparently that short a run of chain will overheat in very little time, approx 15 mins according to Muffet eng
That is exactly why the Fiat 126 doesnt have my Quaife atb fitted -
What car is this going in do we know ?
Most of the Italian mini car series of autoslalom cars are 126,500,600 Fiats, are very small in the wheelbase, but their runs tend to be less than 2 minutes, they use chain driven diffs, with the engine mounted across the chassis, so overheating chains are not a big deal.
The engine could also be mounted behind the rear axle, with the sprocket facing forward. there is an autograss guy got a Sunbeam Stilletto with this setup. Weight distribution would be fairly wild on a wet road I would imagine.
post us some pictures ?
Not sure how well the Zcars guys get on with their chain driven diffs, but my Fiat has only 10" or so between centres, the mini has quite a bit
more wheelbase than the Fiat 126 , which is tiny...
If they can get along with them, then why are you trying to do different ?
Have you tried the Miniforum ? there is a Zcars section there with lots of pics etc.
Food for thought, get yourself to the Autosport show at the NEC this weekend, there will be a stack of autograss cars there, and they are a really
helpful bunch.
Get some pulleys and use a supercharger drive belt instead of chains, less noise and wear. A few bikes use belt drive.
quote:
Originally posted by Peteff
Get some pulleys and use a supercharger drive belt instead of chains, less noise and wear. A few bikes use belt drive.
was going to say, putting a bike engine in the middle of a mini is not exactly rocket science, and certainly doesn't require gear cutting. As I said, there are two ways to do it without open chains, and without too much expense.