"Long Shank Pinions" still too short - RC-Monster Forums

himalaya · 03:58 AM

I have a Tekno Conversion Kit for 8-T. I prefer direct motor drive than the clutch. But I found my motor seems too far apart to the spur,

even I have bought optional "long shank" pinions and "motor plate for long shank pinion". I have to pull the pinion out for a few mm to make the pinion have good couple to the spur, and thus the outter set screw(the one near the teeth) is completely loose, no use at all, only one set screw is actually tightenning the pinion to the motor shaft.

I tried Novak HVpro, Feigao XL, Align 600XL and many other motors, all the same, they use a standard shaft length of 16mm.

For stock mod 1 pinions from Robinson or Novak, no way, they are just too short to touch the spur!

So my questions are,
Is there any way I can move my motor a few mm closer to the spur?
Would Tekno have a "LONGER shank pinion" coming out for those using standard motors? or at least
Does Tekno recommend any other motors that have longer shaft ?

For future coming kits, would Tekno make more choices for customers to choose from? such as a kit includes NO clutch, and move the motor mount holes forward for 10~20mm so that I can use standard stock pinions.......

Thanx.

teknorc · 12.05.2008, 04:10 AM

Quote:

Originally Posted by himalaya

I have a Tekno Conversion Kit for 8-T. I prefer direct motor drive than the clutch. But I found my motor seems too far apart to the spur,

even I have bought optional "long shank" pinions and "motor plate for long shank pinion". I have to pull the pinion out for a few mm to make the pinion have good couple to the spur, and thus the outter set screw(the one near the teeth) is completely loose, no use at all, only one set screw is actually tightenning the pinion to the motor shaft.

I tried Novak HVpro, Feigao XL, Align 600XL and many other motors, all the same, they use a standard shaft length of 16mm.

For stock mod 1 pinions from Robinson or Novak, no way, they are just too short to touch the spur!

So my questions are,
Is there any way I can move my motor a few mm closer to the spur?
Would Tekno have a "LONGER shank pinion" coming out for those using standard motors? or at least
Does Tekno recommend any other motors that have longer shaft ?

For future coming kits, would Tekno make more choices for customers to choose from? such as a kit includes NO clutch, and move the motor mount holes forward for 10~20mm so that I can use standard stock pinions.......

Thanx.

Hello,

Strange, this is the first we've heard of this. Either way, one set screw will still work fine especially considering the tight fit (close tolerances) on the pinion gears. The clutch assembly is longer and heavier and only uses one set screw without any issues. I'm pretty sure the Neu and Medusa motors have slightly longer shafts (19mm-20mm).

Semi Pro · 12.05.2008, 01:53 PM

Quote:

Originally Posted by teknorc

Hello,

Strange, this is the first we've heard of this. Either way, one set screw will still work fine especially considering the tight fit (close tolerances) on the pinion gears. The clutch assembly is longer and heavier and only uses one set screw without any issues. I'm pretty sure the Neu and Medusa motors have slightly longer shafts (19mm-20mm).

dont you feal that extending the pinion out that far will put alot of stress on the front motor bearing?

and lead to failure?

MetalMan · 12.05.2008, 02:38 PM

Quote:

Originally Posted by Semi Pro

dont you feal that extending the pinion out that far will put alot of stress on the front motor bearing?

and lead to failure?

That's what I was gonna say... I can forsee some extremely fast-wearing front motor bearings with a long-shank pinion that's hardly attached. Not to mention greater wear on gears as a result of more flex between the pinion/spur.

himalaya · 12.08.2008, 12:44 AM

Exactly. That's why I was strongly recommending move the motor forward for 10~20mm, saving the bearings while allowing use of standard pinions we can get just about anywere. But that seems impossible on current chassis. Tekno might consider to offer an individual none-clutch version of their conversion kits.

teknorc · 12.08.2008, 03:24 AM

Quote:

Originally Posted by Semi Pro

dont you feal that extending the pinion out that far will put alot of stress on the front motor bearing?

and lead to failure?

As mentioned in the earlier post, the Elektri-Clutch sits out even further and we have yet to wear out any bearings prematurely. As long as your mesh is set correctly, the long shank pinions will work fine. There are many people running the long shank pinions without issues.

We thought about making a separate conversion for use with standard pinions, but it is simply too costly to offer all of the variations. The current design accommodates clutch or direct drive while allowing us to offer the conversions (with a complete chassis) for a very reasonable price.

himalaya · 12.09.2008, 01:34 AM

Agreed, your price is very reasonable, especially nowadays.
When I purchased in Aug. it costed me $200 and now Mike is selling it for only 120 bucks...... Patience is a virtue.

Ryu James · 01.13.2009, 10:21 PM

i have actually had this same occurence on my 8t kit. what i did was purchase the Robinson RAcing wide tooth spur and was able to just get the 2nd set screw to grab the motor shaft and still have the pinion and spur mesh up. it was very close to make it work but it worked out. sometimes you just have to play around with these kits and try different things. most of the time it is something we are doing wrong rather than something with the kit.

are you trying to set your mesh so that the spur gear sits in the center of the pinion? because the pinion gear has much wider teeth than your spur gear. just link up the two so that the pinion gear teeth just reach far enough to match the spur. you dont have to have the pinion teeth reach beyond the spur teeth. is this making sense? i bet if you do this you could probably get that 2nd set screw to just catch the tip of the motor shaft. good luck.

himalaya · 02:36 AM

Thanks Ryu. I got your point.
I changed my motor from Feigao to Castle/Neu, the latter one does have longer shaft so the 2nd set screw fits well.

But I found another problem: Gear mesh can NEVER be set correct with a 12T pinion.
Even moved the motor to the closest position, there's still a gap between the pinion and spur, about 0.3mm，making the mesh too big and generates terrible noise when running.

No choice, I have to increase either the pinion or the spur. But for a 2200KV 6S config, bigger pinion will likely overgear the motor. I bought a Robinson Xtra wide 49T spur, just one tooth bigger than the stock Losi 48T. It's on the way and will certainly solve the problem.

George16 · 01.14.2009, 05:50 AM

Increasing to 49T gives you an additional 1mm to the overall diameter of the spur over a 48T. Hopefully, that would be enough to close the gap between the pinion and spur.

teknorc · 01.14.2009, 01:24 PM

You can also try dremeling the slots on the motor plates in the direction you need a little more movement in.

himalaya · 02:41 AM

Quote:

Originally Posted by teknorc

You can also try dremeling the slots on the motor plates in the direction you need a little more movement in.

Yes, that's another good solution. But the slots are machined countersunk, hand-dremeling them while maintaining same accurate countersunk angle seems a little tough than simply replace to a bigger spur.

I may have to add spacers underneath the center diff mounts to keep the bigger spur from being destroyed by the rocks and sand running backward under the chassis.