View Full Version : Question: R90 TT Metal Fan Differences
Does anyone know what the differences are between the 2 different fans sold by ThunderTiger for the Raptor 90? It seems they have one for OS engines and one for YS.
I currently have a YS90SR. Will either fan work for me or do I need the YS specific one?
I don't think my LHS will have both in stock and I need one ASAP.
Thanks in advance.
Bill
Maxime30
06-19-2008, 04:23 PM
OS and YS engines apparently have different cranckshaft threads.
My 90 3D came with a plastic fan specific to the crankshaft of the OS ( and some other ) engines. They say I'd need a different fan for a YS, but they also say it's possible to re-thread the fan with an appropriate tap (M8x1mm) for the YS engine .
Badger50
06-19-2008, 06:24 PM
Yeah you do have to run a special YS fan for the 91sr. This is the one I usr from HP, http://www.heliproz.com/prodinfo.asp?number=136239 I think it works just great. Just remember to use a fair amount of blue locktite to keep it on the 91sr, she can be a beast to start when she is new. Good luck to you.
That's very interesting. I've been flying my R90 3D since Xmas with the black plastic fan that came in the kit. I have a .91SR in it. I bought the heli from a local hobby shop and the engine from Heliproz.
What is all this talk about different thread pattern? Am I using the OS fan on my YS? I'll try and get pics later.
Badger50
06-19-2008, 08:15 PM
That is interesting. When I ordered the heli from HP, the guy told me that I needed to run this fan, the instructions in the manual said the same thing on page 32 of the 90 3D manual. Have you had any problems with runout or alignment. Would be interested to know. Thanks.
Maxime30
06-19-2008, 09:35 PM
They clearly say you can re-tap the fan that came with your kit ( 90 3D at least ) to fit the YS. I guess that with a little persuasion, the fan will re-thread itself if you force it on the YS crank (though I'd use my dial indicator to make sure runout is within .002" )