Originally Posted by skyhawk

I'm sorry yours have failed Merlin - however I have 6 of them and I know a lot of others that have these green motors and have not had any problems with them. I don't think they really need any improving (except to bring down the price!)

Maybe you just got a couple of lemons - or they may have had a bad batch.

Remember when they 1st came out? A lot of problems. I got mine from Tower Hobbies and i think they were from an early shipment. The replacement still runs I think. I/m just put off by them. If i crash I want it to be my fault not an equipment problem. Maybe I'll try again someday but not with a GWS motor. For now I'll watch jamesdr fly his EDFs and I'll stick with props.
MERLIN

Originally Posted by MERLIN V16

Remember when they 1st came out? A lot of problems. I got mine from Tower Hobbies and i think they were from an early shipment. The replacement still runs I think. I/m just put off by them. If i crash I want it to be my fault not an equipment problem. Maybe I'll try again someday but not with a GWS motor. For now I'll watch jamesdr fly his EDFs and I'll stick with props.
MERLIN

I'll second that.. mine were full of defects (holes not tapped right, different amp draws, iffy bearings)..... Mine are buried in my 262, but they run hot on 3S and don't work very well.. no doubt will be the death of my 262 at some point..

I just did this to my rotors:
http://www.rcgroups.com/forums/showp...6&postcount=49

82T gear, 9/32" drill bit, and my current draw went down by 5 amps!

How does that modification reduce current draw?

Originally Posted by rdeis

I just did this to my rotors:
http://www.rcgroups.com/forums/showp...6&postcount=49

82T gear, 9/32" drill bit, and my current draw went down by 5 amps!

Originally Posted by rdeis

I just did this to my rotors:
http://www.rcgroups.com/forums/showp...6&postcount=49

82T gear, 9/32" drill bit, and my current draw went down by 5 amps!

??????????????????/

The latest GWS rotors come with a back plate as shown in this photo, No1, of the latest EDF-75 rotors. I have done a similar thing on the EDF-64 using a 6 mm Depron disk, photos Nos 2, 3 & 4 .

What I think happens is that without the disc the rotor blade area is only supported by the front of the rotor cone and can therefore develop a wobble at the rear. This wobble will have the same effect as an imbalance and lead to a lower RPM and therefore a higher amp draw. The disc stabilizes the rear of the cone and allows a higher RPM. A higher RPM on the same motor/fan/ battery set up means that there is more back EMF and therefore there is a lower current draw.

Ken

Originally Posted by RCDad

How does that modification reduce current draw?

I believe it stiffens the rotor and reduces vibration as Ken said. Cleaner rotation reduces draw.

Reduces wear and tear on the rotor, too, so it's less likely to throw a blade.

Several people have done this in different ways with pretty good results, I found the gear the easiest, took me 5-10 minutes to do both rotors.

The same size gear works for EDF-55 rotors.

rdeis,
Man, 5 amps is a lot for two motors. Are you still using the VL hand wound motors? I'll have to try this to see if I get about the same with the 55's. I do think the 55's are a bit stiffer though and ballance better then the 64's.

What glue did you use? I'll prop try the rubberized CA and light ply disk.

Thanks for posting the link--Stacker

Originally Posted by stacker

Man, 5 amps is a lot for two motors.

It sure is! I'm racking my brain to figure out if anything else could acount for the difference. I might have removed a little debris from the exhaust duct in between tests, but I don't think so. I ran it up fo 5-10 seconds on my wattmeter, pulled the rotors and installed the disks, reinstalled them, and ran it up again for 5-10 seconds. I didn't recharge in between, so that might account for a small decrease, but not 5 amps!

Are you still using the VL hand wound motors? I'll have to try this to see if I get about the same with the 55's. I do think the 55's are a bit stiffer though and ballance better then the 64's.

Yes, same motors, still seem to be running very well. I've got two more of them that I plan to install in my GWS 15 when I get around to building it. I think I'll be looking for a good 4s wind for them, though.

I agree that the 55s are stiffer than the 64s, will be interested to see your results.

What glue did you use? I'll prop try the rubberized CA and light ply disk.

Rubberized thin CA. The fit is so neat that you almost don't need it.

rdeis,

Thanks for the info. I'll try to mod several rotors on one of my 262's. Be nice if I could shed a few amps.

As I remember, I think you were running the same setup as me, 5 turn nsnsnsns? Mine was all 55's though. I bet you could use the same wind for you F15 but with four cell bat. prob. be around 22-25 amps.

Cheers--Stacker

What other adhesive could be used for someone doing this mod? Thick CA maybe? I am going to use 6mm depron.

I'd stick with thin glue because:
A> you want a tight fit and
B> thin glue is less likely to glob up and ruin the balance. (you should probably re-balance the rotor afterwords anyway.)

If the disk fits as well as it should, then thin foam-safe CA would do the trick.

Originally Posted by speedracer24

What other adhesive could be used for someone doing this mod? Thick CA maybe? I am going to use 6mm depron.

You will need to use foam safe glue if you use Depron.

I cut my 6mm Depron discs very slightly oversize and forced them in so they were under compression. This way they are in so tight that to get one out you have to cut it into pieces. Make a simple tool to ensure that you push the disc in straight

Ken

I made the discs and installed them. They sound alot smoother and quieter than before. Thanks for the info guys.

Very nice mod. Improves performance (higher RPM), more efficient (lower AMP draw), and may even help to prevent that dredded in flight impeller destruction (more structural support).

I'm going to do it to mine!