Production Tolerances...

johnrtse · #1 12-12-2002, 11:21 PM

My first MicroSizer was a 49Mhz Lancer. I noticed a lot of gear slop/gear noise in it. I put in a white 7-tooth Hot Wheels K.I.T. racing pinion gear and reduced the gear noise and improved top speed considerably, of course (I also installed the KIT 2.6 orange motor).

I tried to install the white 7-tooth pinion (along with another orange 2.6 motor) in my new 27 Mhz Blue Impreza and got SERIOUS gear bind! The car wouldn't even move.

Anyone else had similair experiences installing parts in supposedly identical cars??

John

MTL · #2 12-12-2002, 11:28 PM

yep ive had that problem too...
although with other motors, ive noticed that the white pinion makes it "seem" like its spinning faster, and youd think it would go slightly faster with an extra tooth, but i couldnt tell when its moving...

Mr Freeze · #3 12-12-2002, 11:47 PM

I posted something along these lines myself... but nobody seemed to come to this same conclusion.

http://tinyrc.com/forums/showthread....&threadid=4420

One of my cars is as loud as h*ll no mater what gears are in it and another is super quiet. I would bet that this would probably make two "supposedly identical" cars run at different speeds. I've come to the conclusion that my loud car has a less than idea gear meshing due to production inacuracies(sp).

Readers Digest Version:
I agree with you 100%

ryanhook · #4 12-13-2002, 11:31 PM

I've noticed the same variances in quality. I now have 3 Bits and there's highly noticeable differences in gear noise, performance with different motors, varying antenna lengths on the chassis and varied antenna lengths on the transmitters.

Needless to say, I'm not too impressed.

Mr Freeze · #5 12-14-2002, 12:33 AM

Slot cars seem to have the same probs even in the high end cars.
The gear miss-meshing(new word) on the bits doesn't seem like it can be fixed. Just sell the warped cars and buy new ones hoping to get one that had a better release from the mold.

Ryanhook:
Have you tried some of the mods??? They really make a difference. www.questformaddness.com has most of the best ones.

Mr Freeze · #6 12-14-2002, 12:34 AM

...that should have been www.questformadness.com ...

johnrtse · #7 12-14-2002, 07:57 AM

I actually wish my Subaru had the gear slop that my Lancer has- then I could use the white 7-tooth pinion gear (versus the black 6-tooth gear they come with).

The white 7-tooth gives a very noticable increase in performance, and just gives me one more component/variable to play around with in my quest for speed!

John

Mr Freeze · #8 12-14-2002, 11:10 AM

I imagine that more gear slop means less efficient. Properly meshing gears don't rattle and bang around wasting energy by creating alot of friction. With larger RC cars we used to mesh the gears with a piece of paper stuck between them. When the paper came out the mesh was just right.

ryanhook · #9 12-14-2002, 03:10 PM

Quote:

Originally posted by Mr Freeze
Ryanhook:
Have you tried some of the mods??? They really make a difference. www.questformadness.com has most of the best ones.

Actually, QFM is how I came to find these forums. I've read through all the mods many times over. Last night I removed the cripple capacitor on my Skyline GT-R set's transmitter but it hardly helped with the range.

As for problems with the gears, I've used graphite-in-oil based lubricants but all they've done is quiet down the noise. The car still doesn't go any faster/smoother.

Which mods would you suggest I try?

Mr Freeze · #10 12-15-2002, 12:22 AM

Hmmm...

-The telescopic antenna did a bit for me in range increases... more in coolness factor.
-The crip cap in the car was a huge boost. I'f you haven't tried that one I think you should seriously consider it.
-Independant front suspension seems to me to be a coolness thing but as a result I can lower the bodies further without having a sabilizer bar.
-Haven't done the batt mod but I will when I can get ahold of some.

I tried graphite myself on my "Bad" car and it just didn't seem to make a big difference. The biggest boost was to take a piece of paper and jam it between the motor and the back of the chassis. When I clamped the heatsink down it forced the motor and pinion closer to the big? gear and really made it quiet. I did have to file off a bit of plastic to alow the motor to move foreward like that though. Kind of a band-aid solution untill I fix it for good... maybe some plastic shims.

The tip about putting the metal tab on the back of the motor to the back of the car also helped tighten the gear mesh for me too. Translation: the car runs quieter with it at the back than it does at the front.

BTW: this car is my test dummy for all mods. If it can't keep up with the pack...

ryanhook · #11 12-15-2002, 01:24 AM

I'll take your suggestions into consideration. I'm using my original Skyline as my "test car" you could say.

Unfortunately my biggest complaint in variances in production have to do with the varying performance that I have experienced with my Bits.

I posted this in another thread in regards to motors not performing well:

Quote:

I recently purchased a 2.6 and 3.0 Tomy motor for my first Bit and I experienced the same problems (well, not THAT slow but slow).

My car at the time was the white 27MHz Skyline that shipped with a 2.2. After burning-in the new 3.0 I gave it a run and found that it was slow — not only accelerating, but in the top end. To say the least I was very disappointed in the performance of the 3.0.

Last week as an experiment, I dropped the 3.0 in my friend's Bit and we both couldn't believe the difference! It ran as it should have initially — VERY quick!

Since that time I picked up a used yellow 27MHz Lancer and put the motor in it. It too ran faster than my Skyline but not as fast as it had ran in my friend's Bit.

This week I received my Skyline GT-R set in the mail and put the 3.0 in it. Finally! In this car it performs exactly how it performed in my friend's unit.

The 2.6 also runs great but my original Skyline Bit is a slug no matter what motor is in it. I have no idea why there would be such differences. I've even noticed that my roommate's blue 35MHz Skyline was faster when we first received our first Bits.

It starts to make me wonder about the consistency of quality with each of these cars. As another example, my new Skyline GT-R set came with a super long antenna on the car and yet a much shorter (about 6" shorter) antenna on the transmitter (this has resulted in a very short range) in comparison to all the other Bits I have. Very odd!

So what am I trying to say? I'd suggest trying the motor in another Bit before jumping to conclusions about it. You may find that it's something to do with the chassis and not the motor.

More than anything, I'd say that the varied performance I'm getting between cars that are sharing the same 3.0 motor is my biggest disappointment. It's taken up to my latest car to get one that actually performs the way a 3.0 motor SHOULD perform! THAT is really unsatisfactory.

Mr Freeze · #12 12-15-2002, 02:00 PM

I noticed another post regarding Microsizers and their excellent customer service. It sounds like Hobbico is really trying to please by handing out new chassis and cars when there is a fault in workmanship. I can't remember the thread but you could find it with a search. I suggest at least sending them an email to see if you can at least score a new chassis

Another thing to note:
If you are brave enough to take the pcb cover off and risk knocking the little copper wires loose...
I took a look inside my cars and the little copper wires were touching both the battery terminals and the leads on the pcb where the wires go to the motor itself. Now I'm not an expert but I think that any conductive metal touching these points and crossing conections should be detrimental. I took some time to move these copper wires so that they don't touch anything they aren't supposed to. I wonder if something like that could cause shorts and permanent damage to the circuit?!?

A question for you:
With the motor out of your problem car, how freely does it roll???

I'm not making excuses for poor workmanship I'm just trying to help you get your moneys worth out of your existing bits.

ryanhook · #13 12-15-2002, 04:43 PM

Thanks for the advice. Unfortunately all my Bits are true Tomy Bits shipped straight from Hong Kong so I don't think Hobbico would be of much assistance.

As for your suggestion regarding looking under the PCB cover, since the tabs on my first one have broken off, maybe I'll investigate that on it (it's also the one that's the slowest).

In regards to the motors, they move quite freely. And as I had said, they work wonderfully in select cars (i.e. my Skyline GT-R chassis, my roommate's Skyline, and my friend's other Bit).

It's a mystery that I can't solve just yet.

Mr Freeze · #14 12-16-2002, 09:07 PM

Ahhh... I was looking at Ryanhooks post regarding Microsizers.

To rephrase my question

With the motor out of the car how freely does the car roll???

mjb · #15 12-17-2002, 08:36 AM

Quote:

Originally posted by Mr Freeze
I took a look inside my cars and the little copper wires were touching both the battery terminals and the leads on the pcb where the wires go to the motor itself. Now I'm not an expert but I think that any conductive metal touching these points and crossing conections should be detrimental. I took some time to move these copper wires so that they don't touch anything they aren't supposed to.

These are enamelled copper wires -- unless you've scratched them, or attacked them with solvents, they are insulated, so the shouldn't upset anything. They touch all over the place, especially where they go into the front housing ...