Questions: IVOPROP Medium IFA

[dginok]

I just happened upon this discussion about the IVOProp IFA motor. Not long after my first flight in October of 2017, I started to have a string of failures with the prop electric motor armature. After spending way too much money on replacement armatures, I was determined to get to the bottom of the failures, or at least find a cheaper alternative.


I got in touch with John Holmes at Holmes Hobbies in Missouri. He specializes in custom motors for remote control enthusiasts. The 540 type motor used in the IVOProp is among the motors he makes and sells. John was enthusiastic about helping me find the culprit.


John examined more than one of my failed armatures and determined that the failures I was experiencing were due to the armature windings shearing apart. Eventually, we found that the breakage would occur where the windings meet the tabs connecting them to the commutator. This may or may not be the failure everyone else experiences, but it is definitely the failure I was having.


At some point along the way, I balanced the Medium IVOProp using Dorsal's generously-shared prop balancer. I wanted to make sure I minimized excess vibration as a source of motor failures.


During the time I started having these motor failures, I was developing a constant speed controller for the IVOProp. The many activations of the motor during constant speed operation no doubt exacerbated my motor failure situation.


John Holmes attempted to cure the winding breakage with an epoxy he had on hand. He applied this around the top of the armature, hoping that it would prevent the windings from shearing at the tabs. That attempt lasted only a few hours before I had another failure. John's epoxy was relatively soft, so we wondered if a stiffer epoxy might be the answer.


To make things easier on myself, I decided to try to roll my own armature, making a jig to machine the armature shaft so that it would accept the small gear that drives the IVOProp gear box. Once I was able to machine the shaft, I could experiment with readily-available, low cost armatures.


I followed John's lead with the epoxy idea, but used good-ol' Hysol 9460 to encase the top section of the armature windings. I did that with a twelve-dollar, twenty-seven turn armature I bought off of eBay (actually that was the whole motor; I only used its armature). I have not had a failure since -- about 140 hours so far -- even with the abuse the motor takes from the constant speed controller. I do keep a backup armature handy -- I bought one of the Holmes Hobbies hand-wound armatures, modified its shaft and epoxied its windings.

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[Slyfox]

since I cleaned and switched out the lube in the gears in the system (in front of the motor) I have had very good luck with my motor, not to say I won't, I have another motor that I'm going to now open up and look at the armature and glue for future use. I would definitely be cleaning the gears and putting the grease that I stated above along with the glued armature. My prop now changes very fast and will go to each stop where it wouldn't with the lube that IVO put in. I also found the 3 little gears closest to the motor was wallowed out in the center that rides on the pin.

[Slyfox]

one question Doug, can you resolder the connections on the armature before gluing ?

[dginok]

I think I tried that one time without success. I'm pretty sure John Holmes also warned me that it would not work.
Once I was able to use cheap armatures, it was unnecessary.

Correction: I tried soldering but not with the epoxy, so I don't have any experience with the combo.

one question Doug, can you resolder the connections on the armature before gluing ?

[Slyfox]

I used the super lube and really like that lube. anyway, I just took my new motor that started skipping and soldered the connections, went real well and than put some hysol like you did, got it drying. will try the motor in a couple days. thanks for the heads up.

[Slyfox]

when I soldered I just went over the connections which are crimped. the solder did flow real nice inside. I do want to say again that the motor worked better than ever after just cleaning out the old grease and putting in the super lube grease(synthetic) I truly believe that the old grease was putting quit a strain on the motor and that I feel could be putting extra pull on the motor causing connection problems(wire burn out), just my opinion, doesn't hurt to try everything. also when I put the glue on, I covered the connection points as well for the wires.

[dginok]

Steve,

Early on I found this from auto-gyro.com: AG-SB-2017-05-B-EN: IVO-prop gearbox overhaul
They were having the motor failures and suggested gear box re-lubrication. I did that per the bulletin. It did not help that I could discern.

since I cleaned and switched out the lube in the gears in the system (in front of the motor) I have had very good luck with my motor, not to say I won't, I have another motor that I'm going to now open up and look at the armature and glue for future use. I would definitely be cleaning the gears and putting the grease that I stated above along with the glued armature. My prop now changes very fast and will go to each stop where it wouldn't with the lube that IVO put in. I also found the 3 little gears closest to the motor was wallowed out in the center that rides on the pin.

[rc300xs]

I appreciate your input and thank you! I thought I was alone on this.

I might have led myself down the wrong path but I determined it was heat and too many amps. I tried a resistor as well as a lowering the voltage to 7.2 - 8.4 vdc. What do those two voltages remind you of? I opened the housing and found myself reminiscing of my days building RC cars. I was surprised to see a familiar motor. Impressively simple which I’m a huge fan of.

I had issues with the armature showing an open. After replacing three motors and fixing 2 of them I had enough and went back to the ground adjustable. Each time IVO would send me another RC motor the same thing would happen after 10-20 hours. I started pulling the motors apart and found they measured wide open between the armature pads in all combinations, I narrowed it down to the connection between the winding and the tab of the contact pad. I only once found that it was a broken wire, in my case it was the solder that would become detached from the copper wire and leave black soot around the wire, through the solder under the tab and out the other side. (Like a cold solder joint with black soot) I inspected this with a microscope and it looked like it was literally burned open. I heated the solder and bent the tab up out of the way, then carefully cleaned the copper wire to get the soot off it. Next I measured from tail end to end and the entire winding loop was good. Next a little flux and bent the tabs back down over the wire and soldered it good. I now measured around 1.9 ohms between the pads. After using the motor for a few more hours it would quit again. Upon a second inspection I found the exact same thing. It was like the solder wasn’t attached to the wire anymore. Maybe vibration did this? Not sure exactly but I’ve never in my life seen solder break away from copper while it’s encased in it. (Other than maybe a cold solder joint). Maybe that’s what’s happening as well, again I’m not sure. This same failure happened on three motors and again on both of the motors I fixed. One of the motors I fixed however, on one of the tabs, did show a break in the wire right where the wire meets the solder. I believe that break was due to me removing the goop they had to steady the wire from vibration and centrifugal force, so I could work with it.

Finally I went with a whirlwind and parked the IVO for a while. I called IVO and explained the situation and asked what the solution is. They seemed to NOW acknowledge that I wasn’t the only one with this issue but didn’t directly admit it (I got the feeling from them that this is a known issue now, in previous dealings with them they acted surprised). They said they’ve switched manufacturers and are now selling a new and better motor to resolve the issue. I ordered a motor and yes it showed up looking different. The new style is painted black and has the IVO Prop logo on it. For reference the older style motors are chrome. I tested this new motor and it works, but I haven’t tried it on the plane as I’m looking to sell the works. I’ll install and run it if it doesn’t sell as I love this IFA setup when it works. I should add that when it works it works exceptionally!!! Very impressed and a huge thanks to IVO for making such a great system. Not so much when it quits and I’m 3 hours from home stuck on fine pitch doing 85mph compared to the 115mph I normally get. Or I’m in short stuck on coarse pitch. I learned that lesson once and now I always check the prop that it will go fine pitch before landing short strips.

To sum it up, if the winding maintains continuity with the armature I’m sure there’d be hundreds of hours trouble free operation.

I also completely disassembled the planetary, cleaned and lubricated. Turns much easier now.

Pelican PL
912ULS
Murle Williams through hub mod (highly recommend)
IVO 70” medium 2 blade

[Slyfox]

I appreciate your input and thank you! I thought I was alone on this.

To sum it up, if the winding maintains continuity with the armature I’m sure there’d be hundreds of hours trouble free operation.

I also completely disassembled the planetary, cleaned and lubricated. Turns much easier now.

Pelican PL
912ULS
Murle Williams through hub mod (highly recommend)
IVO 70” medium 2 blade

I might of stated all I did, but I got a motor from IVO with a black case at the time, the casing had scratches on it, but all internals were new, rebuilt. I installed the motor and took everything apart on the gearing and cleaned with brake klean and put my universal synthetic lube on all gears, inspecting the gears the 3 top gears closest to the motor was wallowed out in the center, replaced those. Now I haven't had any trouble in a long time now, this was at least a year ago I did this. I fly over a 100 hrs a year on this plane. Now interesting is also the prop had much more movement, it went to a finer pitch, crazy. changed much faster as well. My thoughts is with the white grease it was causing a bind in movement and causing electrical strain. meaning it was causing more amps through the wiring. I had problems with the screws loosening for the brushes in the motor, about every 5 hours I would have to remove the cap and tighten because it quit. than the screws would strip on the end for the driver. what a mess, than the motor would quit all together, the armature was shot. I was totally ****ed. I haven't had a trouble in a long time. I feel good.

[dginok]

David,

Thanks for sharing your experience as well. I also thought I was having unique issues, particularly after IVOProp assured me they had updated the motor and those armatures also failed. Undoubtedly, the constant speed controller makes the motor work much harder. I don't have a lot of experience with props, and none with constant speed props prior to my IVO setup, but I am enjoying the prop very much since I resolved the motor issues.