rctori

Hi,

I have just installed a plastic spur gear in my Revo 3.3. I did the paper thing and it came through smooth with a little pull. There is also barely any play in it.
I pushed the truck across the floor and it sounded normal....to me (I'm still new at this).
I do have a steel spur gear to install, but I thought if I'm going to screw up something I'd rather it be a gear than transmission, etc.

Is there any other ways to check the gear mesh or should I start her up and go from there?

Thank you rctori

stoya789

hi rctori, i have done the paper gear mesh thing for years. I recently read an article in car action magazine (might have been xtreme rc cars magazine) basically saying that the paper way to set the mesh is wrong. the mesh is too loose from using paper to set the mesh.  it reasoned that modern gears have proper spacing "built into" the tooth design itself such that the teeth can never bottom out. it mentioned the proper way to set the mesh was to use no paper at all, to gently press the gears together and tighten. I will try to find the article and scan it for you.

rctori

That would be great! I'm just trying to avoid stripping it continuously.

Thank you

stoya789

Shabbernigdo

i duno. ive done the paper trick for about 16 years now and have never had an issue from it.

The only time ive striped a spur is when the set screw on the motor / engine came loose or somthing found its way in between them. rock / stick / finger

Argess

I never liked the paper method, but I do adjust mine for the lash (free play) that paper would achieve, if the paper method was more consistent. I find with paper, you can't tell if the CB/pinion to spur has any pressure on it. Once you remove the paper, the lash can tighten up.

I don't agree with the article as the lash will change during operation. In a Savage, the lash becomes less when the engine torques as it moves towards the spur gear a bit due to flex in the assembly. Other vehicles might need a tighter lash if when the engine torques, it moves away from the spur.

In the article, the pic shows what looks like an electric vehicle with a very rigid pinion to spur mounting system. In that case, minimum lash is likely the best, but I would still have some lash.

For my vehicles, I just gently snug the engine down and use a flat bladed screwdriver to move the mounting screws slightly back or forth in their slots (with a twisting action) until I get the lash I want. Then I tighten the mounting screws and the lash usually doesn't change as everything is already snug. Then if I want to use blue loc-tite, I just take out one screw at a time, apply a drop of loc-tite, and re-install. If I feel I can be quick, I just loctite all the screws from the get-go, make the adjustment, and then fully tighten.

I admit, it's a "feel" thing. To check, I just hold the spur from moving and then rock the CB. I'm checking for just a bit of free play. I then rotate the whole thing a few times, and if there are any tight spots, I widen the lash so that no spot is tight.

Automan

Never used the paper method, just going by feel and look and how it sounds.

rctori

It sounds normal to me. I rolled it across the floor (with engine off of course) and it was smooth and I didnt hear anything catching or inconsistent. I'm going to start her up tonight and see how it goes.

Thanks everyone for the input.

rctori

ThunderbirdJunkie

My Feedback: (3)

Since ThunderbirdJunkie has nothing of consequence to add since Argess' post was so good, he will simply state that as soon as he read "rock the CB", he instantly thought "Rock the CasBah".

Never Enough Toys

My Feedback: (11)

+1 For Automan! You took the words right out of my mouth..Especialy how it sounds under load/power.

rctori

I started her up last night and it was perfect! ran great. Now when I hit the thottle on the remote the truck goes backwards?? I tried looking it up on google and the traxxas site and it didn't help much. 

Eman77

Might have to reverse the transmitter throttle setting?

rctori

Is that the throttle trim?