Motor height setting problems

[SeniorSpaz87]

Hello,

So I've fixed most of the issues with my M4. But now the motor won't settle in place. The slightest turn of the tightening piece will make it go from just touching to locked up... Any advice?

 

Oh, and the "sweet spot" changes every time I unlock the motor...

[RR01]

Have you remembered to put the metal plate spacer between the motor and the baseplate/adjuster screw?

[SeniorSpaz87]

Have you remembered to put the metal plate spacer between the motor and the baseplate/adjuster screw?

Maybe... O_o

[SeniorSpaz87]

Ok, some pics of the two parts. I honestly can't see / find anything matching your description there...

[Samurai]

This plate has the big adjusting screw, it doesn't need that intermediate part.

[SeniorSpaz87]

This plate has the big adjusting screw, it doesn't need that intermediate part.

Ok then, back to square one...

 

Any other ideas? It's so close....

[Sitting Duck]

Daft silly question.........

 

When replacing switch and working on wiring inside

did you mess about with gears/shimming - were they removed/knocked and not refitted correctly ???

coz a bevel gear set too low will put greater strain on motor as you wind the motor inwards

and pushes the bevel gear very hard into bushing/bearing creating stress for motor/box & heat too for motor

 

I started to follow very bad out of date instruction at first and know first hand what can result if bevel is shimmed to low

[SeniorSpaz87]

Daft silly question.........

 

When replacing switch and working on wiring inside

did you mess about with gears/shimming - were they removed/knocked and not refitted correctly ???

coz a bevel gear set too low will put greater strain on motor as you wind the motor inwards

and pushes the bevel gear very hard into bushing/bearing creating stress for motor/box & heat too for motor

 

I started to follow very bad out of date instruction at first and know first hand what can result if bevel is shimmed to low

Quite possibly...

 

I've taken this M4 apart enough that I can put it together in the dark. So it's perfectly reasonable to assume I put a gear in wrong. Guess it's time to take the damn thing apart again...

[Sitting Duck]

As a very very very ROUGH guide......

 

Box open, no spring/cylinder/tappet plate etc....

Start with big middle or Spur gear & bevel gear....

 

bushings: require much less shims than bearings

thin shim under spur gear & few shims on top

bevel gear few shims underneath & thin shim on top

 

bearings - similar but will require say 2 thin or a medium shim under spur & on top of bevel - then a tiny bit more to take up "slack"

 

Sector is done last after those gears and shimmed as what is required - but after spur/bevel

 

The bevel gear is shimmed a tiny bit higher than a tiny bit too low - coz as motor is wound inwards it forces the bevel gear up

a bit - more so if bevel is too low being forced upwards to get a good "mesh" between motor/bevel

if bevel is way too low it is forced tight against bushing/bearing and really strains the motor and box.....

 

NB: please note this is a very very rough guide and please seek out a few videos on how to shim - watch a couple at least with good reviews/comments

I only put this rough crap description together to try and describe where I was going wrong on my first lot of gearbox tinkering......

It really was a bad set of guidelines I was following on a repair kit instruction that only after I googled and watched stuff I realised what bollox I was doing

 

you should check and really take your time in shimming and aim to get it as best as you really can, don't aim for perfect zero play shimming

a little isn't bad when holding box together by hand - but should test by tighten - NOT MEGA TIGHT the box up, coz when screwed up that

little play by hand halves itself when screwed up....

The way the gears lay/sit, a tiny gap as gears lay in box but don't cross etc.... - sounds simple but can take 6, 12 or more attempts

to acheive the best possible shimming results you can get or get within your own skill/patience/ability etc....

 

The better it is shimmed the longer it will last - fit the best possible bits in there but if they are just chucked in even a

crap box with pi$$ poor bits but properly assembled box will last longer