Flex shaft/collet issues

[awfireman]

I just installed a TP Pro Comp 3650 TD 1680kv motor in my PB Sonic Wake. During the first run the boat ran good and fast....for about 3 seconds and then started to bog down. I pulled the boat out of the water and noticed the flex shaft winding was all messed up.....not spiraled in about a 3 inch section. I had a spare flex shaft an swapped it out. Boat ran excellent for about 25 seconds then the same thing happened. I pulled the boat up, took the cover off so I could see shaft and collet. I held the boat in place by the nose and hit the throttle....collet spinning but not the shaft. Both times I tightened the collet down pretty hard? Thinking it might be that the flex shaft isnt tighting down properly for some reason. Is there a certain distance that flex shaft needs to ride up on the collet? This new motor is longer than the Dynamite and when putting the shaft into the collet it bottoms out, leaving a perfect 2mm spacing between prop and stinger. What am I doing wrong here?

Thanks for any help or suggestions.

Fireman

[chevelledude]

Pull the shaft and check to make sure the stub shaft is not loose from the flex shaft. Mine let loose on second run

[awfireman]

I think I need to move the motor a bit more forward so the collet is clamping the flex shaft where it is soldered? I just checked it and the flex shaft is bottoming out on the motor post and when I tighten the collet it may not be clamping on the very tip of of the shaft where the solder is, but more back on the flex shaft windings. Would this cause the problem I am having? The flex shaft spinning when out of water but once any sort of pressure in the water, it doesnt spin? I have never had this issue before and wondering if there is is a proper placement of where the collet connects the shaft. Any help would be great if anyone knows.

[30nitro]

I would try trimming the flex shoter...and not moving the motor..using a dremel cut off... i have never used soldered flexs...others may disagree... but none have come loose or un raveled..... Try it.

[Johnc]

Could it possibly be the wrong handed flex?

[awfireman]

Could it possibly be the wrong handed flex?

I have a stock flex and one from OSE. Motor is spinning counter clockwise which I believe is stock setting. The prop is going to proper way as well when spinning

[fweasel]

If the collet has spun once, it's pretty much junk, and needs to be replaced. It's also possible that a slipping collet can ruin the end of a flex cable, necessitating that both parts be replaced. The flex cable bottoming out against the motor shaft is not an issue, and actually how I prefer to set mine up, so that the gap at the drive dog gets set without having to even look at it. The soldiered tip is more about protecting the cable stands from unwinding. I don't run soldered ends on any of my cables.

[properchopper]

I haven't ever seen a Sonic Wake collet but I suspect that as a budget, hobby grade rig the collet may not be up to the job, especially after power plant upgrades and likely after flex slippage has occurred

I just kind of dodged this bullet while building a hardcore P-Cat for a customer. He sent me a collet which was pretty much guaranteed to create slippage problems - of all things, besides being rather tiny, it was chrome plated - not the best surface to create a non-slip grip . I substituted an everyday Octura collet - much bigger and made of a way more grippy material. Also, best to apply some anti-seize to the threads - helps a more consistent tightening.

collet 2.jpgcollet 1.jpgcollet 3.jpg


Octura 5mm to .187 collet here on OSE : $ 13.99

[awfireman]

Thanks for the info weasel. I was thinking that myself and the collet will be replaced with a Speedmaster. Along with the motor, I replaced the stock ESC with a SK180 and Doctor Props tornado 2 blade. This boat was super fast for the 30 seconds it did run on the second try before having the same issue with the flex shaft. Ill will also keep the motor where it is. Thanks for your help!

[awfireman]

Thanks Chopper. The stock collet is just what you described...shiny chrome. I suspect this is the problem and I had this issue one other time about 2 months ago after greasing, when the boat was all stock. Collet was probably junk then. I need a new flex shaft but nobody has them in stock. Will have to wait to see the boat run unfortunately. Thanks for your help

[awfireman]

Chopper...on those Octura collets, I noticed the grub screws are off set and do not sit on the flat part of the motor shaft. How do you mount this to the shaft? Just slip on and tighten grubs? I may order one of these as Speedmaster collets are out of stock @ OSE.

[properchopper]

Chopper...on those Octura collets, I noticed the grub screws are off set and do not sit on the flat part of the motor shaft. How do you mount this to the shaft? Just slip on and tighten grubs? I may order one of these as Speedmaster collets are out of stock @ OSE.

I locate one screw on the flat, and just tighten the other. You may find that the longer Octura may need a little fitment-fiddling if it has trouble living in the space between the motor and stuffing tube. Sometimes a little Dremel therapy is called for, but worth the effort

collet size.jpg

[properchopper]

Thanks Chopper. The stock collet is just what you described...shiny chrome. I suspect this is the problem and I had this issue one other time about 2 months ago after greasing, when the boat was all stock. Collet was probably junk then. I need a new flex shaft but nobody has them in stock. Will have to wait to see the boat run unfortunately. Thanks for your help

Since I'm processing/buzzing on my morning caffeine overdose, I'll keep going and add that rather than wait for the Proboat flexshaft part to come into stock, just make your own * - I can walk you through You'll need that trusty dremel with a cutoff wheel, the drive dog & prop nut from the original, and (if your anger management class tuition is paid up), I'll explain how to nicely tin the tip

* notice that OSE stocks replacement shafts with two different size propshafts (and requires a setscrew groove dremeled in)

coffee.jpg collet shaft comp.jpg collet shaft tip.jpg