gearbox issue

[SSTSparkz]

I had an issue to day where a bb made its way in the the rear of my gearbox and got lodged where the sprind sits, i was told about what i believe is called "shrimming" where you take the last tooth out of the piston so it stops gen lock ups. how ever once i grinded this tooth down I can no longer get a full cycle and it seems like even tho my gearboxs look like its in good shape there are about 4 teeth still trying to push the sping back when it is all the way. Ill attach a picture.. but any ideas? should of i done this at all?

heres the gearbox.
[IMG]www.southsidetribe.com/downloads/gearbox.jpg[/IMG]

[tisane]

Re: gearbox issue

That pic dont work.
It sounds like youve put the sector gear in wrong.
You need to make sure the smooth part of that gear is towards the piston not the teeth.
And "shimming" is nothing to do with teeth removal if that is what you meant.

[SSTSparkz]

Re: gearbox issue



hoping that this image works this is how I have the gearbox set up as I would close it. with terms then forget what i had said but i removed the last tooth on the piston which apparentlly stop jams?

[richardy]

Re: gearbox issue

Its not about stopping jams its about preventing premature engagment of the second tooth as the piston returns, in tests the "second" tooth would always be in the way of the gear from picking up the first tooth. You simply "lower" the hight of this tooth so as the gears come round they dont catch it as they try and pick up the first tooth. Its a common misconception that you need to completely remove the whole 2nd or 3rd tooth. After all every tooth you remove is more pressure on the first tooth of the piston becuase there are no other teeth in the early high strain stage to take the pressure.

ok lecture over, in your case it wouldnt cuase jams unless somehow there was now material where it sholdnt be and usually in that case, gears would mash right through the problem.

Testing, remove the spring guide and spring, and tappet plate and spring. Holding the anti reverse latch in its spot, and pushing the piston slightly forward simulating the spring, turn the gears and simulate the inital pick up and pulling back of the piston.. your looking and feeling for anything that is stopping asmooth operation.

was you getting lock ups before the mod, more than likely theres an underlying issue, this mod shouldnt cuase lockups

[TB-Stalker]

Re: gearbox issue

Your sector gear is aligned wrongly, the knob on it in your picture looks almost at 12 o'clock, it should be at 1, rotate the gears a full cycle minus 1 click on the anti reversal latch.

[richardy]

Re: gearbox issue

it doesnt need to be timed or any thing as long as the tappet cam on the gear isnt touching the tappet plate. 1 - 3 o clock is just a good guide to make sure people dont mis align the tappet plate or piston and sector gear. A neutral position.

[tisane]

Correct me if im wrong guys but could that now be missing the first couple of teeth out on the gear causing it to try pushing the piston back and having 2 or 3 teeth left at the end of the cycle causing the lockup??


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[SSTSparkz]

Re: gearbox issue

Correct me if im wrong guys but could that now be missing the first couple of teeth out on the gear causing it to try pushing the piston back and having 2 or 3 teeth left at the end of the cycle causing the lockup??

thats what im thinking as when i opened it while the spring was in that postion it had about 3-4 teeth left to push it back futher, which makes me think why did i bother with cutting the tooth of the piston.

[tisane]

I still might be corrected here but unless you have double fire issues with it id just go out and get a new piston and start again without taking anything at all off the teeth.
If yoy still have probs ask the question on here at least before you go butchering it again, could save you a lot of time and money.


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[richardy]

Re: gearbox issue

The sector gear looks fine, as much as you can tell with out inspecting all the teeth closely.

The gear will move the piston back enough to go from piston tooth 1 too 4 even if you removed 2 and 3. So it woudnt cuase the lock up that way...

You need to do what i said to check for a smooth opperation.. dont just guess at it...

[SSTSparkz]

Re: gearbox issue

If i take the springs off and test the cycle it does nothing wrong. infact in practise it looks like the first tooth on the gear will pick up on the bump bit on the end of the piston and then cycle through and realese the piston. but as soon as I put the box together I see the spring compact and then lock and act as if there is little battery power. and I know the battery work as I have tried both of them and there fully charged.

I will post a picture tonight of the spring compact in the gearbox and with another of where it is locking.

[richardy]

Re: gearbox issue

please try changing the spring guide for a different one and test again.

[SSTSparkz]

Re: gearbox issue

here is the pic of when i open it as its jammed, take note this isnt exsact but the piston fell forward a sooon as the gearbox opened. but a demo of what it looked like...

[mrpugster]

Re: gearbox issue

It's often very difficult to diag problems like these from just a picture but it does sound like where the tooth has been removed it now hasn't got enough to pull the spring back to a point where. I had this only the other day, didn't work till I replaced the piston with a new one - could be wrong though.

Just going to dump my brain :-)

Sometimes you get lockups if you motor isn't aligned properly, make sure you seat it correctly in the grip and attach each spade connector in the right way otherwise the plate doesn't go on correctly.

Maybe have a look at mechbox.com for their decent V2 video - worth a look in just to make sure you have everything where it should be.

Oh and check you haven't damaged any of the gears, no missing teeth...

[richardy]

Re: gearbox issue

16 teeth on the piston, 16 on the sector gear, in the picture youve misaligned it yours self, i dont think thats a true representation of whats happening in the gearbox.

like i say remove the tappet plate and spring and the main spring, push the piston all the way into the cylinder, and hold it there with pressure on the rail guide, now cycle the gears and simulate the piston moving back with slight pressure on it.. what the gears as there move from tooth 1 to 2 to 3 to 4 all the way to 16 and release, and becuase your applying pressure the piston will now slide back into its resting position.

If all the works without you seeing or feeling any jamming then i daubt very much the issue is there with the piston.

for your own peace of mind just buy a new piston, the guarder ones good.