14 tooth pinion

[Dylwad]

Originally Posted by HighFreq

The only thing you could try is make the outside diameter of the owb a bit smaller if it is possible (with a lathe). For production is not a viable way but for few parts maybe it is.



Corrado

I thought about that too, the walls on the owb are only about .65mm thick, I'm afraid if I grind that any thinner the owb will grow in diameter even more when its locked up.

I was thinking too, did you do most of the testing on the old style shaft adapters? with the new long shaft I think there is room for the owb on the 4mm section... 4x8x6mm owb is easy to find, and could use a few 3x6x2mm bearings on the 4-3mm step and top of the pinion. See if the attached quick drawing makes any sense.

[dr dremel]

Now that´s an original idea! Only question is if the OWB should be supported by bearings on both sides? Just noticed that this is the only difference in the assembly apart from stretching out the components.

Edit: The OWB itself would be another size also? Or is it stock size?

[Dylwad]

I don't think the owb needs a bearing on both sides, it's a bearing in itself, and only spins during spool down.

Stock owb is 3x6.5x6

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[sp00fman]

It could work i suppose. the Trex250 has a main-gear with OWB that is supported by only one radial bearing.
Im really in a hurry all of the sudden.


The used kit im fixing had a cracked 16T.....

My new 16T replacement just arrived from Freakware.de......Through the sealed bag i can see the pinion... and a crack running all the way over the new pinion!

Its gonna take me a long time to get it fixed at this pace.

[Dylwad]

Just for fun, we are pushing close to a horsepower through these tiny little needle bearings in the owb on the mini!


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[rossk]

Did u get the power meter setup on this motor?

Those are the pins than ran all over my bench when I stuffed a owb

[Dylwad]

Originally Posted by rossk

Did u get the power meter setup on this motor?

Those are the pins than ran all over my bench when I stuffed a owb

42 amps, 925 Watts peak. As high as 890 Watts at the 3 minute Mark.

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[rossk]

Originally Posted by Dylwad

42 amps, 925 Watts peak. As high as 890 Watts at the 3 minute Mark.

Wholly Shot, I knew it was a power house but thats a lot more than I was thinking!

[Dylwad]

Originally Posted by rossk

Wholly Shot, I knew it was a power house but thats a lot more than I was thinking!

Me too, and that's still only 33c max on the batteries :cool: the motor and esc are handling it just fine, but I know a smaller pinion would be much better.

A stock 3 cell non stretch on a 16 tooth is in the range of 450 Watts.

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[rossk]

Originally Posted by Dylwad

Me too, and that's still only 33c max on the batteries

I know I did the calcs, thats why I was most disappointed when the TP pack puffed up, I knew I would only be drawing in the 30C range, half what they are rated for.

I think that pack is not much good anymore, still performs well, but its IR has gone thru the roof 8+ on each cell, used to be 1/

[Dylwad]

Any pack will puff if you over discharge it. On the 3 minute flight I logged the lowest voltage read was 3.38 volts per cell. What is your LVC set to?

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[rossk]

Originally Posted by Dylwad

Any pack will puff if you over discharge it. On the 3 minute flight I logged the lowest voltage read was 3.38 volts per cell. What is your LVC set to?

Hmm, yes true, I hit LVC in 2mins, set at 3.1
Poor tp pack, I got 80 cycles out of it, nearly $1 a go

[Dylwad]

Still going forward, received the 13 tooth pulley and 14 tooth pulley stock today to do my own tests without a one way bearing, and the design for the new pinion will be finalized soon, and sent off to the machine shop. I think the new design will work out of aluminum too, which makes the machinist happy

[jmisuraca]

Originally Posted by Dylwad

Still going forward, received the 13 tooth pulley and 14 tooth pulley stock today to do my own tests without a one way bearing, and the design for the new pinion will be finalized soon, and sent off to the machine shop. I think the new design will work out of aluminum too, which makes the machinist happy

That's AWESOME

[Dylwad]

Thanks my 3D cad skills aren't the greatest but I can usually get it done. The machinist is excited to get started, he likes odd ball projects. One of his machines is a $130k hass 5 axis :cool:

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[CrashAddict]

Oooohhh Sexy..

Ya know what would be cool? Laser etch the teeth count on the side of it. :-) So, is the thinking that the little bell will help keep it from cracking?

[Dylwad]

Originally Posted by CrashAddict

Oooohhh Sexy..

Ya know what would be cool? Laser etch the teeth count on the side of it. :-) So, is the thinking that the little bell will help keep it from cracking?

Probably no laser etching

The thought is to get the one way bearing out from inside the teeth, to give more material under the teeth to prevent cracking.

Right now the stock 14 tooth has around .25mm of material between the bottom of the teeth and inside bore, this design has close to 1mm~more than the stock 16 tooth.

Just did another log on the 15 tooth and 2520 motor, 950 watts peak

[baui2000]

Looking good! I'm curious how this turns out.

[Mikej]

I just love the lateral thinking - really hope that this works!

[shadco]

Really?

You're doing this.

This would bring me back to a stretched Mini P 6S with the Scorp 2520-1360 in a heartbeat.

The MSH 14T's didn't last very long even at 3S.

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