LOL, yep, I`ll compare `em...8 to 1...

Don`t get me wrong Phil. Neus are the BEST in my opinion, but to quote an old communist leader from WWII if I may....." Quantity has a quality all its own"...or something like that.

Originally Posted by Kevin Cox

Well, my motor arrived Friday and sure enough it is a bit big for the motor tube in the 4" Hayoe. I started to remove some material and soon realized that a new motor tube might be easier for me. I have been busy with home stuff all weekend so this was a quick and easy diversion.

Looking through the junk I collect, I found a thick cardboard mailing tube and I decided to work with it. Using a 2 1/8 hole saw and 1/4 thick ply this will be the motor mount.

Using a razor saw I removed the existing motor tube from the fan shroud. The cardboard was wrapped with a layer of 3oz glass cloth and should have been coated with epoxy, since this is a test piece I used thin CA. After a narrow width of carbon fiber was glued inside, the ply wood mount is inserted into the tube end. This made the fit perfect! When completed it will be attached to the stators with Hysol epoxy.

After the glue sets I will cut the cooling and mounting holes. I have about a 1/32" clearence on the motor, which should be enough.

Then I will see what the numbers look like on 12S! (behind a protective barrier of course)

Nice work Kevin. Sorry I didn`t get back to your PM earlier. To remove the material on my 4" fan, I made a large sanding drum. I took a large hole saw and wrapped 40 grit sandpaper around it. Then used it to open up the motor tube.

The 4" fan motor tube is 1 mm smaller in dia than the 4.5" or 5" fan. So it is harder to fit the motor, but it can be done.

Here are a couple of pics of the windings. I flew two flights yesterday with peak amps at 120a on 10s.....so over 4kw. I was more worried about puffing my batteries than I was cooking the motor, so I kept my full throttle stretches to about 20 seconds or so, but I wasn`t taking it easy on the system.

I`m posting a pic that is out of focus, but it shows how bright the windings still are. They look like new to me. This motor has some beef in it. I`m more impressed every time I run it.

I agree that 880 is too high of a kv for a 5" fan if you want to run 12s. It would be nice to see a 650 kv or so. I`ll bet Turnigy will do it when they see that guys are using them in these fans.

When I get my extra motors, I will see about rewinding one to a lower kv.

Originally Posted by Knife Liddle

LOL, yep, I`ll compare `em...8 to 1...

Don`t get me wrong Phil. Neus are the BEST in my opinion, but to quote an old communist leader from WWII if I may....." Quantity has a quality all its own"...or something like that.

Pls don't get me wrong. I'm totally with you on 'value' alternatives But I've already forked out for the Neu's, so now wud be delighted to see comparable figures on the 4in Haoye.

For curiousity, the other useful comparison for me is the static thrust vs. kWatts-in. IMHO, these figures are good gauges of comparative fan efficiencies. I appreciate you all for doing a good job & sharing info.

Phil

And don't forget weight in that equation! How much weight does a system take to make its power! Example if. A extra cell or larger motor only makes its weight more in power what's the advantage. And if it takes more cell or more mah what's gonna be the long term cost of always bigger packs.

Barry

Originally Posted by Knife Liddle

.....I agree that 880 is too high of a kv for a 5" fan if you want to run 12s. It would be nice to see a 650 kv or so. I`ll bet Turnigy will do it when they see that guys are using them in these fans.

When I get my extra motors, I will see about rewinding one to a lower kv.

I agree the 880kv is way too high for the 4.5in Haoye. I found out the hard way 850 was too high for my 4in on 12s of Nanotechs. Well, I may be able to slip by with the better fitting heatsink. So can't wait to see Turnigy bring out lower kv versions.

Phil Lin

Originally Posted by monkamarm2000

And don't forget weight in that equation! How much weight does a system take to make its power! Example if. A extra cell or larger motor only makes its weight more in power what's the advantage. And if it takes more cell or more mah what's gonna be the long term cost of always bigger packs.

Barry

Hi, Barry!

I thought about your input a bit. I know it is a valid point. Your concern really is a desire to have a measure of the efficiency of the whole power set-up or propulsion system. May I propose Lb (s-thrust)/kW-hr/Lb(system-wt)? I know it's is quite unweildy & requires a bit more data; but I think it encapsulates your thoughts on this subject for quite a while.

Meanwhile, Lb (s-thrust)/kW is a good measure of comparative fan/motor eff'cy

So much for this. Let Knife Liddle go on with his experimentation.

Phil

Lee, It seems guys are finding the kv on this motor to be higher than the spec says.
It shouldn't be too much of a problem to rewind, but I understand it's not for everyone.

BTW, the Turnigy 80-100 I rewound was helped out a lot by fitting 25% more copper than the factory with the same number of turns.

Steve C

Originally Posted by Steve C

Lee, It seems guys are finding the kv on this motor to be higher than the spec says.
It shouldn't be too much of a problem to rewind, but I understand it's not for everyone.

BTW, the Turnigy 80-100 I rewound was helped out a lot by fitting 25% more copper than the factory with the same number of turns.

Steve C

I'll measure the unloaded kv to add my data to the pool. I'll have 3 motors so we can see how they compare. I did take the bell off of this one to get a better look at the copper and was very impressed with the quality of the wind. The wind is very even and tightly packed on this motor. I don't think you could get even one more turn using the same size of wire and number of strands.

My guess is that it will take 2 or 3 more turns to drop the kv down to a good spot.

I'll get some better numbers later this week when my extra motors get here.

Originally Posted by Knife Liddle

Nice work Kevin. Sorry I didn`t get back to your PM earlier. To remove the material on my 4" fan, I made a large sanding drum. I took a large hole saw and wrapped 40 grit sandpaper around it. Then used it to open up the motor tube.

The 4" fan motor tube is 1 mm smaller in dia than the 4.5" or 5" fan. So it is harder to fit the motor, but it can be done.

Not a problem Lee, I fully understand. I did a search on some of your other work and saw that you mentioned sanding drum. I tried it but after a few minutes I opted out.

Now I am looking for screws for the motor. Anyone know the size?

Originally Posted by PhilLin

I agree the 880kv is way too high for the 4.5in Haoye. I found out the hard way 850 was too high for my 4in on 12s of Nanotechs. Well, I may be able to slip by with the better fitting heatsink. So can't wait to see Turnigy bring out lower kv versions.

Phil Lin

Oh, so you burnt up an 850kV in the Hayoe 4"? Hmmm, I might have to start at 10s. Thanks for the info.

Originally Posted by Kevin Cox

Not a problem Lee, I fully understand. I did a search on some of your other work and saw that you mentioned sanding drum. I tried it but after a few minutes I opted out.

Now I am looking for screws for the motor. Anyone know the size?

4mm. I got mine at Home Depot

I got my extra motors in today. I`ll post new data from the 4" fan as soon as I get one fitted with an intake ring. I`ll also post some pics with the bell off to show winding detail and motor construction details.

Originally Posted by Kevin Cox

Oh, so you burnt up an 850kV in the Hayoe 4"? Hmmm, I might have to start at 10s. Thanks for the info.

Yes, Kevin. That was with a 1515 (a shorter motor), a poor fitting heat sink, & new 25c/50c Nanotech's (vs. some 2+yr olds). IMHO, it should be okay with proper fitting heatsink I now have. Been flying with a 1521 780kv as a replacement I think the latter has maybe 1oz more mass than the Turnigy?

Not intending to hijack your thread, Lee; but I think such info is useful.

Phil

Originally Posted by PhilLin

Yes, Kevin. That was with a 1515 (a shorter motor), a poor fitting heat sink, & new 25c/50c Nanotech's (vs. some 2+yr olds). IMHO, it should be okay with proper fitting heatsink I now have. Been flying with a 1521 780kv as a replacement I think the latter has maybe 1oz more mass than the Turnigy?

Not intending to hijack your thread, Lee; but I think such info is useful.

Phil

Sure, no problem