Well it happened the pinion transfered from the stock motor to my brush-less failed along with the stock main gear. No sense spending another 16.00 for a new motor just to get the pinion. So it was time to do something about the lousy gear selection that we were limited to.

Items needed:
Dremel
MicroHeli TRex 150T CNC Main w/auto. rotate (Just happened that I had one) MH-TX4102
one shaft lock collar (Need to order one from parts list)
one pinion (I have just happened to have a 14T from My 450XS)

UPDATE 4/9/2007 ONE CAN ALSO USE THE ARK X-400 GEAR TOO MH-XH4102

1. Make a mark with a marker between swashplate and the top of the upper bearing housing (on top of the plastic) to keep shaft alignment, this will keep pitch settings.
2. Needed to grind the back-half of the gear housing to match the front half
3. There is a screw hump in the front of the motor, needs to be ground smooth for motor adjustments
4. Leave the bushing that goes on the lower bearing in place and test fit gear-look to see if more needs to be ground off
5. Install upper bushing-upper shaft lock and lower gear shaft lock. Verify shaft position from mark made earlier
6. Install Motor and pinion, Make adjustments for pinion height and gear mesh

I did a bench test and all seems to work well.

Did my field test (5 Packs and a hour later) and every thing went well. The 14T pinion is a bit much for the head speed, I'll try a 11T and see how it goes. Still waiting for the parts so I rigged the main shaft to keep the gear in place. Drilled a hole above the gear and installed a screw and nut.

Headspeed RPMs with a 3500 Kv BL @ 86% head eff. 150T main gear.
9T 2000
10T 2200
11T 2450
12T 2670
13T 2890
14T 3100

Now here's another great thread. If I didn't have to rebuild the top end of my truck I'd be doing this right now. Are the CNC Flybar Carriers FINALLY available?

I was hooked to a site that was taking orders for the CNC parts but they are waiting just like everyone else is[&o].
I've rescinded my order and using the cash to see if I can marry a complete Blade CP CNC head short of the swash plate with a slight modification to the hub to the Axe.

What a rip on the Axe CNC parts if my mod works I can get 2 complete heads and spare main gears.

That would be one of the best mods Ive seen yet. Let me know what happens.

My CNC head was shipped out yesterday, so it should be here sometime next week, I should get some new servo linkages with double ball-ends. Right now I have 1/8 inch play from bottom to the top of head from the Z bends. One reason it flys @ 4 feet and all of a sudden it taps the ground.
I think this should be the last mod. I do other than getting a CF Tail boom and if the mod. works the Helimax CNC swash plate and some nice blades and on and on and on, whoops forgot, I really need to shift funds to the 450xs and get it air borne. But the Axe won't be forgotten I'll treat it well with new radio signals from the new radio using memory 2 from the 450xs on the same freq.

If the Trex has a 5mm main shaft and the Helimax Axe CP has a 6mm shaft, how does the gear fit on the Helimax shaft?

When the sleeve is used for a 5-mm shaft it makes up the difference, so the stock shaft is a drop in fit. But since the stock shaft is a soft metal it might not last long do to the wear on spin downs. I have not tested the life of the shaft, I progressed on using a TRex shaft with sleeve and married a blade cp head which required milling the top of the shaft down to 3-mm and replacing the main bearings to 10X5X3. If I had to do it again I would have used a TRex head also (less work).

I put on an MX400 main gear a while back and it has worked pretty well with the Axe's mainshaft. I did have to do a couple of things though to make it work.

I had to press out and flip the one-way bearing so I could center the gear without cutting the frame.

I also had to flip the mainshaft and drill a new hole for the rotorhead bolt. The reason I did this was so the bearing didn't have to ride on the flat spot cut for the Axe's stock main gear.

Has there been any wear on the Axe mainshaft from the bearing running on the aluminum?

Not really. Wear hasn't been a big issue. The main problem is some shafts are undercut. Their diameter is slightly smaller then it should be. It's not much maybe 0.1mm or so, but it's enough to cause a bit of play in both the mainshaft bearings and one-way bearing. It still works pretty good though.