Spinners
 

Hello,

What kind of spinners are people using for electrics? Are most of you using Tru-Turn or are there some better options out there. If you are using something different, do you have the website? I am getting stuff together and will be flying electric next year! I will be using a Plettenberg Xtra 30-10.

Thanks,
Emory.

RE: Spinners
 

Hi Emory

I am using the TT spinner on the Xtra 30-10. TT also makes an adapter kit which replaces the kit included with the motor so you dont have to find some metric bolt.

Bob at TT can hook you up.

RE: Spinners
 

Hey Chad,

Was it you that cut some extra holes in the spinner to help with cooling the motor? If so, do you feel like that helped?

Thanks, Emory.

RE: Spinners
 

Hi Emory

Ya that was me, if it did help I dont have the instruments and test consistency to be able to determine yay or nay. It certainly was not a 10C drop in temperature of the motor....

It may have helped to hold down the temp when it was really hot like in Muncie, but with only a few days in that kind of weather I dont think I could say for certain.

I have another idea for spinner modification that I will probably try out next season, right now if I go flying you could wrap the motor in a blanket and it would still run cool LOL

RE: Spinners
 

Too bad nobody seems to make a spinner like this for pattern applicatons.
--Derek

http://www.hobby-lobby.com/images/dkt3623.jpg

RE: Spinners
 

Yep we definately need some spinners with cooling holes to get some air through the outrunners.

/Erik

RE: Spinners
 

I have something in the works now. I need to test it and get some data to prove it works. But since I do this air flow and cooling thing for a living...Its going to work. Just might need some tweaks of the details.

its a different concept than I think anything that's currently be used to cool these motors.

I'll be posting some pics in the next couple of weeks. I'm finishing it up pretty much as I write this.

Troy

RE: Spinners
 

I had to go to using a smaller spinner than normal to cool my Plettenberg. Difference in temp was about 10 F, maybe a little more... looked funny at first, but then I got used to it. Kind of looks like the intake to a Mig 21.

Troy, I'll definitely be looking forward to seeing what you have come up with. Are you planning on coming up to Fresno for the Dist. Champs?

RE: Spinners
 

The new 30-10 motors from Plett should deal with the cooling a lot better without any form of modification to the spinner or the aircraft.

RE: Spinners
 

Are they coming out with a new 30-10 or are you referring to the model already out? I have two of them, and they both run hot. 140-160 F depending on the OAT. With the normal sized spinner my temperatures went as high as 180 F.

RE: Spinners
 

There will be two new versions coming out depending on what you want for prop and rpm. They are supposed to have an integrated fan to force air through the motor. One is a high rpm version that is set for an 18-19" prop pushing around 7000 rpm I think, the other was discussed based on the prop I was using in France, the plan is to bring up the current (and therefore rpm) on the 21x13W....probably around 6600 or so for about 69-70A. The current motor may still stick around I dont know. This motor would not run the 22" props but would open the door for more use out of the 21 and 20" sizes and bring up the speed range a bit. Bernd B. was running the high rpm version in France, the other version was simply discussed with Bernd, myself and the Pletti's. Now that they are back from Tucson they are going to start designing the second motor.

The cooling fan has been in use on the Orbit series of motors for some time, as well its on the Terminator and the new Predator motors so its a quick fit to the Xtra series as well.

As for the temperature, even running a standard full spinner with no additional cooling in Muncie this year (90F+) I was only up to 140-150F which was in line with what everyone else I spoke to was getting. I talked to the Pletti's about temps in France, they indicated that 70-75C measured right after a flight on the motor can was still acceptable. 140-160 though is fine.

Around here we are usually around 80-85F in the summer, I barely get much over 120-125F, sometimes 130F.

I am only drawing 61A though.

RE: Spinners
 

The Plett website now shows a spinner assembly for the 30-10 which addresses the cooling issue. The motor mounts in the spinner which has a hole in front to allow cooling air in. A clamp on hub assembly at the rear of the motor can takes folding prop blades.

http://www.plettenberg-motoren.com/z...zusatzxtra.htm

Is this the new motor you are talking about Chad? What blades would one use with it? Apart from the folding blade deal this arrangement looks perfect from a cooling and CG point of view. As Plett say, the prop mounted on the rear of the motor can will also help with vibration issues caused by a lot of overhang from the bearings to the prop.

Malcolm H

RE: Spinners
 

I saw the same on the plettenberg website. And send them an email about propellers....

Plettenberg will sell a 21x13 and 22x12 folding prop....

---- cut from there mail ------
we can deliver you a prop from RASA. We have the 22/12" in stock
and we let produce the 21/13" at this time.
the popeller is like the APC-prop, but a folding prop CFK.

---- cut from there mail ------

Price is about 46 euro!

RE: Spinners
 

Re: Chad's Spinner

Although you can't see it, I found the way Chad had machined the lightened back plate of the TT spinner (with the cut outs) very interesting. He had shaped the spokes like an airfoil (fan) to increase cooling. Genius.

I would love to see true cooling data on this setup. How about it Chad? For warm climate work you could come out to Victoria:)

RE: Spinners
 

Hi Malcolm,

No this is the commercial version of the motor setup attachement that Bernd used during the WC in France.....new motors are still on the horizon :) The one Bernd ran (high rpm smaller prop) and a mid range prop version. I am hoping to know more from Plett next week.

The new controllers from Schulze, and these new motors should make a very good combo for F3A.

Dave,

The holes did help a little, more noticable in very hot weather like Muncie, just seems to hold the temps more consistent flight after flight.....although I have a new spinner cutout idea that I will try next season....right now we are experiencing -15 to -20C and snow :( No more flying outdoors for me this year!

RE: Spinners
 

ok, here is an absurd idea.. maybe
platic spinners use screws on the side that screw into the back plate.. could you cut the tip off the spinner leaving the front open and drill lightning holes and airflow hole sin the back plate?

Let me know if i am crazy.

Chuck

RE: Spinners
 

OK, Chuck, you're crazy ;)

What I was thinking is a take off on the backplate with fins, but have the fins cutout in the spinner itself. If done with a nice integrated cureve to the fins it would also look VERY cool (like something that should be on a hot-rod or custom chopper). Of course, I'd be scared to see what TruTurn would charge for something like that!

Second idea. Create a nose cone that is blunt ended and has what looks like turbine fins in the middle (like looking into the front of a jet engine). The back side of the cone would funnel the air straight down into the outrunner. It may look kinda wierd but would probably cool very well.

Keith B

RE: Spinners
 

Keith,

Thats basically what I did on my backplate, just head to a machine shop and get them to give you a 1/8" carbide end mill that they have worn out and are sending to recycling....they probably have thousands....chuck that baby up in your drill press and have at her :) Makes a nice job on aluminum :)

I think it does have an effect but its difficult to measure without a lab setup....field testing has too many variables!

RE: Spinners
 

Singapore hobby sells those spinners, a friend of mine bought some ($10 each or so) and will be trying exactly what you are speaking of on his new electric model (plett powered) in the spring.....damn winter :)