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Gears Stripping Like Crazy...

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ohmygahitscoby

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Okay. So about to weeks ago I bought a new 1st gear. Then it stripped. So did my 2nd gear, but I figured out I mounted the engine wrong. So today I buy a set of gears. I fit them onto the car and today when I got it running, they stripped... So I'm not sure if it's how my engine is mounted on (It says to make them parallel to the chassis, which I did. They engine doesn't move while I throttle and brake, the space between the CB and gears are fine, etc.) or it's because the engine is too fast that it strips spurs. Can someone help me?
 
After many gallons of fuel through my Tmaxx, I never had a trans problem. What kind of engine do you run?
If it's stock then your slipper is probably too tight, and landings send the shock to the next weakest link, your gears.
 
I run a Mugen/Nova MT12 (or MR12, still trying to figure out). It's the engine that Mugen recommended for the MTX-3. I guess you can say it's stock. I've never had my car jump, so I guess it's not that. Maybe it's the slipper, I'll check.


Edit: I don't think the MTX3 has a slipper.
 
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I'm not familiar with that particular ride, just going for the obvious, for starters. Hang in there, some of the Mugen guys will show up with advise for you.
 
the only things i can think would either be:

improper mesh
wrong # of teeth between spur/cb(some spur/cb gears wont mesh because of the teeth)
bad cb bearings
bent chassis
 
I think it's wrong number of teeth and spur. Mugen suggested a 46, 47, or 48 for the 1st gear, I got a 43. Same for the second gear, I got a different number. I guess that's why.
 
But even when I had the right recommendations, they still stripped. I am currently trying to find it made in harder material, but no luck =(.
 
I am currently trying to find it made in harder material, but no luck =(.[/QUOTE]

IMO, If you are strippng plastic gears I would hate to see what would break if you used metal gears. What would be the weakest link?
 
When working with a 2-speed you do have to keep in mind that only certain gear combinations will work. That's because you have to make sure that the overall distance from the center of the crankshaft to the center of the shaft that holds the spur gears is the same for both 1st and 2nd gear ratios. Think about it this way. If you have an ideal 2-speed setup and then you decide you want more top end. So you install a smaller 2nd gear spur without changing the 1st gear setup. The diameter of this new 2nd gear will be smaller. That automatically pulls it away from the clutch bell and will ruin your mesh. Bang. Stripped gears. So make sure you're using appropriate clutch bell/spur combinations on both gears. There should be some documentation that will outline which ones are appropriate for Mugen.
Also be diligent about your mesh setting. Use the paper method and take your time. There should be a tick of play between the gears, but not much. They should frankly be just short of binding. It takes some practice, and would help if you had 3 hands, but it becomes easy after a while.

ADDED:
http://www.hpiracing.com/graphics/instr/a297.pdf
Here on the HPI 2-speed it gives a rule of thumb that the # of teeth in the sum of the spur/pinion on 1st gear should equal the sum of spur/pinion teeth on 2nd gear. That may be true of the Mugen, too.
 
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I see what Candyman is saying..

-- --- 1st gear
--- -- 2nd gear

-- --- 1st gear
--- --- 2nd gear (doesn't line up, can't change one w/o changing the other)
 
Oh okay. I get it now. The guys at the LHS said the gears I bought will work, NOT. I'm not going there anymore. Haha. Thanks everyone!


Oh, I also found Mugen's gear ratio for the MTX-3.
 
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Why do ALL the guys who are wizards of R/C freely give out their knowledge here, on RCNT, while SO MANY dorks get paid to work in hobby shops pretending to know what they're talking about.

That's an excellent bit of info, Candyman. Learn something new every day.
 
Rolex said:
Why do ALL the guys who are wizards of R/C freely give out their knowledge here, on RCNT, while SO MANY dorks get paid to work in hobby shops pretending to know what they're talking about.
Click to expand...

Because they are smart enough to use their vast knowledge to make more than $7/hr. I think that's precisely why you rarely find REALLY good people at hobby shops outside of owners.
 
Lessen said:
Because they are smart enough to use their vast knowledge to make more than $7/hr. I think that's precisely why you rarely find REALLY good people at hobby shops outside of owners.
Click to expand...

DING DING DING...We have a winner folks.....now remember that next time you ask a kid sitting behind a counter thinking he is god in his little hobby world...and remember how you felt when at 16 you had the attention of adults that hung on every word you would tell them because they trusted you and the shop you represented...now realize you live in the year 2008 and all the crap about being honest and doing a good job and actually having to KNOW WTF you are saying is a sad long lost idea and the reality is this kid probably has NO R/C cars that run, he hates you and the "Stupid" questions you ask of him and he really doesn't care if you screw your rig up because he still gets his 100 bucks of party money at the end of the week.......I used to like my LHS until they started hiring low knowledge couter jockeys instead of people that actually know the hobby......a good LHS is hard to find now, if you have one near you I say support it as best you can so you can keep it.....
 
I was just going to say what everyone else said, so I will say something funny and enlightening

...you don't need a parachute to go skydiving, you only need one to go skydiving twice.....


and all the smart hobbyists don't work in hobby shops because they are to busy working on their cars. These are crappy hourly jobs for these people, people with real know how want to get paid for what they do.
 
Candyman said:
When working with a 2-speed you do have to keep in mind that only certain gear combinations will work.
Click to expand...

As explained in an Ofna manual, the total number of teeth need to match for both 1st and 2nd gear sets.

Example:

1st gear
15 pinion + 48 spur = 63

2nd gear
18 pinion + 45 spur = 63

So if you make changes to either the pinion or spurs, they need to add up to the same total tooth count. This will keep the gear mesh correct. Sometimes people will say you can get away with 1 tooth off on a pinion as the size doesn't change that much, but there is a change in mesh.

Here's changes that would work
1st gear
17 pinion + 48 spur = 65

2nd gear
20 pinion + 45 spur = 65

or
1st
18 pinion + 47 spur = 65

It's pretty easy if you break it down this way.
 
Thanks danketchpel, that made it a lot clearer. Unfortunately I won't be running this car for a while anyways due to my piston and sleeve turning into junk.
 

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