Author Topic: E-Flite motor problems (Read 5734 times)

Russell Bond · « **on:** July 16, 2013, 09:56:36 PM »

A friend of mine wants me to post this as he has no internet.

"I am using the E-flight 32 rear mounted. I think I am having bearing trouble with both of my motors after only about 12 flights with each.
The shafts have developed some movement side to side and when flicked over (and in flight) there is a noise which sounds like bearings, especially during the inside manoeuvres.
Does anyone have knowledge of this problem?"

Dan Bregar · « **Reply #1 on:** July 17, 2013, 06:04:15 AM »

Rear mounting this mtr is the problem. Go with a front mount and the bearing problem will go away.

Russell Bond · « **Reply #2 on:** July 17, 2013, 06:10:58 AM »

Mmmm,
I told him to go with a Plettenburg as they have the 3rd bearing to support the can.
I don't have any problems with my Plettie that is rear mounted.

The trouble is he has finished the plane and I guess he wouldn't want to cut into it to modify it.
An Orbit 20 series will fit as it is similar weight and length.

Will fitting better bearings fix the E-Flite problem?

Dan Bregar · « **Reply #3 on:** July 17, 2013, 06:24:29 AM »

As a general rule, rear mounting is ok on smaller motors running props 11 in. dia. or less. There are some exceptions, but generally this is a rough guideline.

ptg · « **Reply #4 on:** July 17, 2013, 09:06:26 AM »

Hi Russel,

Please forward this info to your friend

It is highly unusual to have bearing problems with E-Flite Power 25 or 32 motors. Both have three bearings. Three years ago I switched from Plettenberg to E-Flite and have logged over 800 total flights. Other top US pilots have similar good experiences rear mounting these motors.

Suggest you look at the motor mount. Most problems noise and vibration occur there. If the mount is wood of any kind that is likely the cause. Bob Hunt sells a firewall/motor mount made G-10 carbon composite that will solve the problem or you can make your own as I do from the same or similar carbon plate material. Another material that will work well but is a little heavier is the printed circuit board material. Either material should be .10” nominal thickness.

Also, I have strong disagreement with the previous post that suggests its OK to rear mount the smaller motors. This is based on experience with the smaller motors ie. E-flite Power 15 and 10 as well as several other brands of small motors. These motors have only 2 bearings and should always be front mounted.

Finally if you do in fact have a defective motor E-Flite stands behind their products 100% and will repair or replace any defective products.

Hope this helps.
Happy flying!

Fred Underwood · « **Reply #5 on:** July 17, 2013, 10:39:07 AM »

I believe the E32 has only 2 bearings

http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLM4032A

and the E25 has 3.

http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLM4025A

That is what I recall from disassembly, also, as I do not believe every thing I read in an advertisement:)

Randy Powell · « **Reply #6 on:** July 17, 2013, 02:41:22 PM »

That's interesting. The specs on the E-Flight 32 I bought say it has 3 bearings. Wonder if they've changed or if the manufacture both.

Fred Underwood · « **Reply #7 on:** July 17, 2013, 03:18:40 PM »

Quote from: Randy Powell on July 17, 2013, 02:41:22 PM

That's interesting. The specs on the E-Flight 32 I bought say it has 3 bearings. Wonder if they've changed or if the manufacture both.

Have you pulled it apart? Perhaps there was an earlier version. That was my line about "not always believing what I read in an advertisement?"

Randy Powell · « **Reply #8 on:** July 17, 2013, 04:12:25 PM »

No, I haven't. it's just what the spec sheet that came with the motor said. Truth is, I haven't looked that close. This is my first electicated plane and I'm doing what I'm told at this point.

Peter Ferguson · « **Reply #9 on:** July 17, 2013, 04:20:24 PM »

Power 32 Brushless Outrunner Motor, 770Kv
Key Features
Equivalent to a 30- to 36-size glow engine for sport and scale airplanes weighing 3.5–6 lb (1.6–2.7 kg)
Ideal for 25- to 36-size 3D airplanes up to 4.5 lb (2 kg)
Ideal for models requiring up to 800 watts of power
High-torque, direct-drive alternative to inrunner brushless motors
Includes mount, prop adapter and mounting hardware
Quite, lightweight operation
External radial rotor design—5mm shaft can easily be reversed for alternative motor installations
High-quality construction with ball bearings and hardened steel shaft
Slotted 14-pole outrunner design
Overview
The Power 32 is designed to deliver clean and quiet power for 30- to 36-size sport and scale airplanes weighing 3.5 to 6 pounds (1.6 to 2.7 kilograms), 25- to 36-size 3D airplanes up to 4.5 pounds (2 kilograms), or models requiring up to 800 watts of power. It's an especially good match for the Gee Bee Tiger Moth, TopFlite DC-3, Phoenix Sonic 25 and 3D airplanes such as the E3D.

Product Specifications
Type: Brushless outrunner
Size: Replacement for a 30- to 36-size glow engine
Bearings or Bushings: One 5 x 14 x 5mm Bearing, and One 5 x 11 x 5mm Bearing
Wire Gauge: 14
Recommended Prop Range: 11x7 to 14x10, (10x10E tested on 5S in Sundowner 36)
Voltage: 12–16.8
RPM/Volt (Kv): 770
Resistance (Ri): .02 ohms
Idle Current (Io): 2.40A @ 10V
Continuous Current: 42A
Maximum Burst Current: 60A (15 sec)
Cells: 10–16 Ni-MH/Ni-Cd or 3–5S Li-Po
Speed Control: 60A brushless
Weight: 200 g (7.0 oz)
Overall Diameter: 42mm (1.70 in)
Shaft Diameter: 5mm (.20 in)
Overall Length: 50mm (1.90 in)

Fred Underwood · « **Reply #10 on:** July 17, 2013, 04:25:27 PM »

I looked at a few bearing sites and found an old version of the E32, but the difference was a flanged bearing, or not flanged, on the front, still only 2 bearings. One 5x5x11 and the front 5x5x14. It sounds like the changed the sheet:)

Not that it matters much, it is what it is.

ptg · « **Reply #11 on:** July 17, 2013, 07:15:22 PM »

Quote from: Fred Underwood on July 17, 2013, 04:25:27 PM

Not that it matters much, it is what it is.

I was trying to help……not start a spec debate!

The point here is not how many bearings, what kind, how big, flanged etc. The real question is did the bearing(s) fail or is it something else.

A couple of other places to look/questions re. noise and vibration are.
1.   Are you using some sort of prop adapter extention?
2.   Are you using a longer shaft then the one that comes with the motor?
3.   Are you using some sort of nose weight attached to the prop adapter or shaft?
Any of the four things could cause the noise and vibration.

The main reason I posted here is that the E-flite motors have been ‘rock solid performers’ for me and have provided a lot of trouble free flying.

I sincerely hope Russel’s friend finds the problem and solves it.

Russell Bond · « **Reply #12 on:** July 17, 2013, 07:49:02 PM »

Thanks for the replies.

He has 2 motors and they both do the same.

I believe he has the normal type slide on collet with no added weight or extensions.

Alan Resinger · « **Reply #13 on:** July 17, 2013, 08:12:29 PM »

Russel,
Your friend wrote me to ask about the problem. I've given him the scoop on the E-flite 32. It has 2 bearings and I replace the factory bearings with bearings from Boca right from the start. The 32, due to its weight probably should be front mounted. I use the Hunt mounting plate now after making my own version originally. Your friend is a little hesitant about retro fitting his plane with a front mount but I told him it really isn't a big deal. I think that I'll probably convince him that the E-flite is a perfectly suitable power plant. My new ship has 170 flights since mid March and I just changed bearings as I thought I could detect some bearing noise.
Alan Resinger

Russell Bond · « **Reply #14 on:** July 17, 2013, 08:49:15 PM »

Yes, he just rang me and told me he contacted you.

I'm trying to convince him to buy the Plettenburg.

He says he's a poor pensioner.....Yeah, Right!!!!

Hahahaha!!

Fred Underwood · « **Reply #15 on:** July 17, 2013, 10:32:22 PM »

Quote from: ptg on July 17, 2013, 07:15:22 PM

I was trying to help……not start a spec debate!

I sincerely hope Russel’s friend finds the problem and solves it.

Sorry, I did not mean to start a debate or hijack the thread into a spec debate. I also use E32.

Dean Pappas · « **Reply #16 on:** July 18, 2013, 01:14:01 PM »

Hi Guys,
There are some "standard" outrunners that use two bearings stacked at one end to help absorb the bending loads and still keep the diameter of the central pylon small, but the Pletty (and the Hackers from the 40 size on up) have a third big diameter bearing supporting the edge of the bell. That's what makes them special from a mechanical standpoint.

take care,
Dean P.

Russell Bond · « **Reply #17 on:** July 18, 2013, 05:37:17 PM »

Thanks for all the replies, I'll forward all the info to him.

Robert Redmon · « **Reply #18 on:** July 21, 2013, 05:26:38 PM »

FWIW, I have two E-32s that I purchased about a year ago. Both had bad bearings from the beginning, but I initially refused to believe a new motor would come with bad bearings, so I just flew them and ignored the strange rattling sound. Eventually, they both developed bearing play, so I replaced them. Suddenly, the rattle went away and all was fine. Yes, the E-32 has two bearings. One is the larger 14x5x5 flanged bearing on the stationary end of the motor.

Regardless, these motors work very well for me. E-Flite must have gotten a bad batch of bearings, and I was unlucky enough to get two from the same batch. The bearings are not difficult to replace once you realize they are glued in with some kind of bearing set adhesive. I used a little acetone on the end of a paintbrush to soften the bearing set cement. After replacing the bad bearings with SS replacements from Boca, they have given no trouble whatsoever.

Bob

Paul Walker · « **Reply #19 on:** July 23, 2013, 10:06:33 PM »

Quote from: Dan Bregar on July 17, 2013, 06:04:15 AM

Rear mounting this mtr is the problem. Go with a front mount and the bearing problem will go away.

Rear mounting is fine. Get rid of the 2 blade and use a 3 blade.
The Predator has about 300 flights now with no noticable change in the bearing "slop". Used only a 3 blade on these flights.

Russell Bond · « **Reply #20 on:** July 24, 2013, 12:17:09 AM »

Yes, he's fitted a 3-blader (modified for electric) onto his motor and the bearing noise went away. Also the prop was an improvement on the APC.
I'm trying some 3 blade props at the moment and they seem to work well.

Keith Renecle · « **Reply #21 on:** July 24, 2013, 12:34:04 AM »

Hi Russell, I mostly rear mount my motors these days, and I like Crist's extra bearing across the front as well. Some months ago I was testing a Pletty motor in one of my old models that I often use for playing with new motors. I had to rear mount it because it has that big fan up front and no shaft out the other end. This 10 pole motor has loads of torque and on start-up as the motor kicked in it took the nose right off the old model. Fortunately it pulled one of the wires off and stopped. I thought wow......I know that the old model is a bit weak up front, but this motor really kicks on startup! I beefed up the nose, but it started cracking again on startup, so I added the front bearing on a ply plate across the nose. This cured the problem immediately. I'm also not sure why Plettenberg use only two screws in the mounting plate. Other than that, it is really a gorgeous piece of work. Having said that, the MVVS motors are also that sort of quality but at around half the price, I believe they are a better deal. I do intend to try a few E-Flite motors soon.

Keith R

Russell Bond · « **Reply #22 on:** July 24, 2013, 02:38:55 AM »

Hi Keith,
Yes, I was worried about the 2 screws only on the Pletty, but in 3 years I've had no problems.

I'm sticking to them at this stage as I like the 3rd bearing that supports the can and I don't want to front mount it.

On another note, how's your timer going with 10 pole motors, mmm?

??

Dan Bregar · « **Reply #23 on:** July 24, 2013, 06:54:41 AM »

Quote from: Paul Walker on July 23, 2013, 10:06:33 PM

Rear mounting is fine. Get rid of the 2 blade and use a 3 blade.
The Predator has about 300 flights now with no noticable change in the bearing "slop". Used only a 3 blade on these flights.

Ahh, a 3 blade ! That would help out the bearing load forces for sure. I didn't think of that option. That's why you are the CHAMP ! Congrats by the way.

Keith Renecle · « **Reply #24 on:** July 24, 2013, 11:51:22 AM »

Quote from: Russell Bond on July 24, 2013, 02:38:55 AM

Hi Keith,
Yes, I was worried about the 2 screws only on the Pletty, but in 3 years I've had no problems.

I'm sticking to them at this stage as I like the 3rd bearing that supports the can and I don't want to front mount it.

On another note, how's your timer going with 10 pole motors, mmm???

I did a program, but the we had to move house and this was a bit of a nightmare, so I have not had time to do any objective flight testing yet. Will Moore has the program for one of his Pletty's and will give us some feedback shortly. I had to sample the rpm pulses in two frames of 20 milliseconds instead of one because of the lower amount of pulses form the low pole count and it's hard to say if there is a noticeable difference, but like I say I have not had time to fly much lately. I have a new workshop to build now and at the same time, I'm trying to catch up with all my timer orders as well, but I am getting there!

Keith R

Alberto Solera · « **Reply #25 on:** July 25, 2013, 02:51:43 AM »

Hi everybody
What bearings are you using as replacement? steel or ceramic balls?
Boca offers three types
http://www.bocabearings.com/bearing-applications/rc-brushless-motor-bearings

I have two OS motors that lasted about 4 flights before the bearings went bad. I have been looking for quality bearings locally but all of them have too much free play right from the start.

Thanks!

Regards

Alan Resinger · « **Reply #26 on:** July 25, 2013, 01:19:10 PM »

The ceramic bearing replacement for the E-flite 32 from Boca Bearing is part # BMK-034C .
The have another ceramic that has slightly closer tolerances.
Alan Resinger

Alberto Solera · « **Reply #27 on:** July 26, 2013, 02:59:59 AM »

Quote from: Alan Resinger on July 25, 2013, 01:19:10 PM

The ceramic bearing replacement for the E-flite 32 from Boca Bearing is part # BMK-034C .
The have another ceramic that has slightly closer tolerances.
Alan Resinger

Thank you very much