Has anyone used these Delrin gears?

[MoparRob]

I purchased some of these because my original gear has a hair line crack on the collar. I'm not sure if I got a bad pair or what but these things slip extremely bad on my Mcp x with a new main shaft. Under hard collective the gear will slip and on One crash I actually had the gear pop completely off . I've had to go back to the stock cracked gear to get reliable flights again. Anyone else experience this with these?

[CyberPlainsDrifter]

sorry to hear about your gear problems.. Delrin or acetal as it is known is a very slippery plastic. Not such a good idea when pressure is being applied to it. Do you have "the groove" in you main shaft? If you can make a shaft w/o that groove, you may notice a difference. Add a small drop of CA and that may also help a bit.

Just so you know, the main gear on an MSR is the same as on the MCPX. They are, for all intents and purposes, interchangeable. I think that there may be one more also , but not sure..

[MoparRob]

Currently I do have the groove or notch in the shaft. When my original gear fails I will probably be CAing the delrin on. The actual gear mesh looked good with the delrin especially compared to my worn original lol.

[Flying_Amp]

I had them, and there totally useless. They are either not machined correctly, or as another poster said the plastic is very slippery. Mine popped off every flight causing a few crashes.

Replaced with an original blade main gear, and all is fine again.

[NCcraig]

Originally Posted by Flying_Amp

I had them, and there totally useless. They are either not machined correctly, or as another poster said the plastic is very slippery. Mine popped off every flight causing a few crashes.

Replaced with an original blade main gear, and all is fine again.

This.^^^^^^^^^

[Vandal996]

I bought them too with the same results.

[bigdessert]

I will throw in a me too here. Tried them just last week and every crash they would fall off. If I spun up too quickly they would slip on the shaft as well. Useless junk in my opinion.

[koko76]

Originally Posted by CyberPlainsDrifter

sorry to hear about your gear problems.. Delrin or acetal as it is known is a very slippery plastic. Not such a good idea when pressure is being applied to it. Do you have "the groove" in you main shaft? If you can make a shaft w/o that groove, you may notice a difference. Add a small drop of CA and that may also help a bit.

Just so you know, the main gear on an MSR is the same as on the MCPX. They are, for all intents and purposes, interchangeable. I think that there may be one more also , but not sure..

Delrin /= Acetal, acetal is one name for a type of polymer, Delrin is a trade name. It is not particularly slippery unless you are talking about specific formulations or filled types, "Turcite" would be one of these, combining acetal and PTFE.
Delrin or other acetals are frequently used to make pulleys and gears in many industries, so the material itself is not likely at fault, more likely the design is poor.
The same gear fits the mCPX, and the mSRX, possibly the mSR as well, but I don't have one of those so I can't verify.

[CyberPlainsDrifter]

~sigh~

http://www2.dupont.com/Plastics/en_U...in/Delrin.html

[jamesandyori]

I like the a look, but they were a big waste of money. I ruined 2 within 2 days.

James

[Flying_Amp]

Wouldnt have been so bad if they popped off after a crash, but mine came off for no reason in flight

[koko76]

Originally Posted by CyberPlainsDrifter

~sigh~

http://www2.dupont.com/Plastics/en_U...in/Delrin.html

Yes, sigh. I'll take 10+ years of designing parts from and then machining various plastics, Dupont Delrin AF, as well as many other filled and non filled acetal co-polymers over a non complete company blurb about their products. Sorry if I offended you by offering a bit more of a perspective from someone who actually works with the material.
I stand by my statement, there are a TON of plastics which would be considered slippery (that page says low friction, not slippery) UHMW, PTFE, Rulon, Torlon or PEEK would be good examples of slippery plastics. www.matweb.com will actually give you numbers too instead of adjectives.

[alex7703]

They are useless. I didn't like them on my MCPX because they slip on the main shaft so easily. I didn't want to waste them so decided to try them on my stock MSR thinking they would hold better since the MSR has less power...WROOONNGG! Don't waste your money.

[DoubleCH]

What about for those who pin their main gear to the shaft? I pin my stock main gear to the mainshaft on my hp05s bird (but not my c05m bird). THe hp05s/9T setup is just too powerful to pressure fit main gear onto a D-shaft. Without pinning the gear, it slips just a bit off the flat during normal flights enough to induce unnoticeable vibration yet still big enough with hp05s/9T headspeed to upset gyro and induces random 90-degree CW kick.

Sounds like for those with pinned main gear, this gear may work just fine.

[Talesin]

Picked up a pair of these with my Wowhobbies MH swash/head/grips order, as my main has taken more than a few hits.
Completely worthless. It's like they were manufactured to fit precisely the diameter of the main shaft (which they do just about perfectly) disregarding the fact that a bit of stretch is needed to press-fit these into place and keep them there. I've been considering a very light layer of extra-thin CA applied and allowed to FULLY dry before installation (just to decrease the inner radius), but it's really not worth the headache to fight with these to get them to work, when a new stocker is ~three bucks from the LHS.

Forget flying... just a few test pitch-pumps on TH were enough to get mine slipping down. Holding it by the head, the gear would fall off completely within 30 seconds.

[John Kane]

I had the same experience. It made wonder if it was even legal to sell something so obviously useless.