Mi1 Belt - Quite stiff
 

Hi all

I am just in the middle of building my Mi1v2 (its a slow process as I only get the odd hour here and there)

I have just added the diffs, belts , spur and layshafts etc and bulkheads / upper deck and the running of the belts feels quite stiff, say if I turn the spur gear everything doesn't move very freely when turning it all tightens up at one point through the turn, any ideas if this is normal or what it could be?

Here is the manual I am on page 12 if that helps

http://www.racing-cars.com/images/Te...-V2_manual.pdf

Thanks Roo

Make sure your belt tension isn't too tight. There needs to be a decent amount of slack on the belts, just make sure they're so loose that they slip. Also as for the belt being stiff, belts do need to break in a little so after a couple runs they will be fine.

-Jeremy

We had a similar issue with my sons one, the belt had a slight kink. We solved this by warming the the belt a little with a hairdryer then running the transmission through an old 540 brushed motor connected to a 1.5 volt battery

Also check that the belt is tensioned the same on both sides

Excellent, thank you.

The belt tension feels pretty loose so far, it's the diffs seem to stick at certain points, with it not being run maybe it is as you said just needs running in. How freely should it all move if i try to turn the spur gear by hand it's all relatively stiff, (stiffer at some points)

Thanks again

Hi,
I have just built one of these and found the hub / wishbone kingpin was binding on the driveshaft. Back off the screw in hub / wishbone end and try again. I think the manual says 0.5mm gap.....I now have slightly more than this and its very free.

Thanks
Darren

Hi, thanks for replying,

Are you talking about the bit on page 14?

everything seems okay there, and also the sticking was there before the driveshafts went in.

So by the end of page 12 when i turned the spur gear everything moves (belts diffs etc) but is quite stiff and at certain points it's really stiff.

Again thanks for helping out, i'm confused to where the tightness is coming from or if it's just because it's new

A simple thing to check is that the layshaft supports are in the right orientation, (these are the supports that hold the shaft for the spur gear) part no. U2449

I have a Mi1 V2 (only got it at xmas) and an original Mi.1 , I got the older one secondhand last week as car for my daughter to run at our local club.

It too was very stiff and notchy, decided to strip it all and have a look at everything, turns out one of the layshaft posts was the wrong way round, the little hole needs to be at the front on both sides, so now a smooth a silk, i was scratching my head for sometime before spotting this, worth a look.

Plus back all the screws off a bit on the top and bottom decks let it all settle and then nip it up across diagonals and then everything should find it's natural home.:woot:

Thanks,

Yes i checked that part, I was overly cautious with the instructions around those parts and luckily they highlighted it in the manual.

I've finished building it now and still can't work out if it's right, it's a rolling chassis now, so can anybody tell me roughly how freely it should roll if say i give it a push on the floor.

it's fairly tight it will move a foot or two with a push.

I know this is really hard to explain, but thanks for all the advice so far.

Take it all apart, build it again. If it's still tight then it may just be a case of the transmission needing to be run in, I doubt if that's the case though.

There's the option to pull it all apart, which will check everything, nothing like getting to know a car inside out, but you shouldn't need to pull everything off the chassis.

Are the diffs in the right way round? worth a check as they do only go one way (that's if you've not checked them) removing the diffs isn't a huge task not all parts need to come off, antiroll bars etc can stay on as can shock mounts etc if you look at is closely a lot of these can stay screwed together so not a complete strip down.

Use a sharpie or some sort of marker pen to highlight the text on the side of each diff so it can be read easily save you pulling it to pieces for no reason.

Another quick check will be to take out the layshaft, then you can see if it's a front to rear belt problem or layshaft to rear problem, pretty quick to whip it out just undo one of the layshaft bearing mounts 3 x screws and make sure u don't loose the little pins that the spur and pulley locate wit.

The front to rear belt should have some movement in it, if its as tight as a drum then there's a definite issue. The layshaft to rear diff belt will be a little tighter but not rock solid.

If all else fails give the chaps a Schumacher a call, they will be more than helpful and give you some pointers, with most belt driven cars they don't run anywhere as free as shaft driven vehicles, it won't roll forever with or without a motor and pinion in it but should be fairly smooth with a push mine do about 3 or 4 feet. the new MiV2 is the most smooth.

The front to rear belt in my cars have about 5-6mm of movement and the tensioner pulley is really used as a guide rather than putting undue tension on the belt.

Hope it helps, when you get it sorted look to set 2 deg of camber all round 2 degree rear toe and 1 deg front toe, 5mm ride height and away you go!

(others will have many variations on this but its a good starting point)

:thumbsup:

Thanks again,

Milesallen - I started to take things apart like you suggested, I have taken the spur and layshaft out and when doing this and turning the rear wheels I notice that as the rear diffs to a complete turn they get slightly stuck at the same point every rotation, it moves freely and then gets slightly stuck at one point and so on.

So I guess this means it's something to do with the rear diffs or the diff mounts or something?

Thanks again, for all the help

Ok, strip the back end down look how the diffs are seated, and bearings etc then slowly tighten things back up, see if the diff is the wrong way round, it should have been pre-built to slot in. the diff should only go in one way but see if the bearings run free etc.

Hope you get it sorted, it will be something and nothing in the end that's causing the problem.

Cheers

Miles
:thumbsup:

Hi thanks,

I have basically taken the whole back end to pieces, the diffs are the right way round, they sit in the house fine but then when you attach the diff mounts is when it starts to run smoothly, so I assume it can only be either the diff holders, the diff mounts or the diff itself?

Maybe something could be bent, as the stiffness comes at the same point of rotation every time.

If you have any more ideas please do let me know, thanks again