CraigJ
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| posted on 7/1/11 at 08:19 PM |
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need help with gears
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.
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dilley
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| posted on 7/1/11 at 08:26 PM |
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Why has the engine got to be installed backwards?
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CraigJ
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| posted on 7/1/11 at 08:29 PM |
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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.
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snapper
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| posted on 7/1/11 at 08:37 PM |
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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
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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chunky2772
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| posted on 7/1/11 at 08:40 PM |
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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!
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chunky2772
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| posted on 7/1/11 at 08:44 PM |
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Also the gears wouldent last two minutes without a supply of oil to them.
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CraigJ
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| posted on 7/1/11 at 09:02 PM |
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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.
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liam.mccaffrey
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| posted on 7/1/11 at 09:13 PM |
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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]
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chunky2772
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| posted on 7/1/11 at 09:20 PM |
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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]
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SPYDER
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| posted on 7/1/11 at 10:30 PM |
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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.
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procomp
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| posted on 7/1/11 at 11:05 PM |
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Hi
Type 9 5speed 5th gears maybe.
Cheers Matt
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steve m
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| posted on 8/1/11 at 05:44 AM |
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"i have an idea don't laugh! mount the diff upside down this will change direction "
yes this would work
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chunky2772
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| posted on 8/1/11 at 09:17 AM |
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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.
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adithorp
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| posted on 8/1/11 at 09:55 AM |
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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.
Oh yes it will!
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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ReMan
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| posted on 8/1/11 at 09:56 AM |
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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]
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blue2cv
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| posted on 8/1/11 at 09:59 AM |
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Diff is to be chain driven, wont matter which way up it is, will still turn same way
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blue2cv
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| posted on 8/1/11 at 10:03 AM |
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Look at www.r1manx.com may give some inspiration
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SPYDER
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| posted on 8/1/11 at 01:19 PM |
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Its a CHAIN driven diff.
Go and think about it again.
Geoff
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blue2cv
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| posted on 8/1/11 at 01:22 PM |
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Do you think the penny will drop Geoff
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indykid
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| posted on 8/1/11 at 01:31 PM |
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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.
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phelpsa
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| posted on 8/1/11 at 01:32 PM |
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quote:
Originally posted by SPYDER
Its a CHAIN driven diff.
Go and think about it again.
Geoff
How about if you mount the chain upside down as well?
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chunky2772
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| posted on 8/1/11 at 02:02 PM |
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ha, ha, I love this!
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CraigJ
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| posted on 8/1/11 at 02:44 PM |
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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.
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NS Dev
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| posted on 8/1/11 at 08:19 PM |
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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]
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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SPYDER
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| posted on 8/1/11 at 08:25 PM |
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[ 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
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