Is this motor too much for the E7 Scorpion 4525-520KV Ultimate? Hell No

[topangler]

Hi Guys,
Does anyone know if the E7 gear train is capable of running this motor (Scorpion 4525-520KV Ultimate)?
I have tried this motor over the last two weeks and stripped 3 main gears in the process.

I have tried using the paper trick to ensure the gear mesh is correct and have also added the alum frame supports to prevent any movement.

During each session the main gear would strip during pump outs i.e. going from a mid stick hover to full pitch.
I have had the local experts/dealers check the mesh and they were happy with the setup and could not offer any explanation for the cause.

I have the main pinion set correctly and also checked the main bearings/shaft for possible movement.

I greased the main gear using a toothbrush to ensure wear was kept to a minimum also, however mute that was, gears won't last longer than one good pitch pump.

My head speed is 2050 and the head is running in Gov mode on the MSH Brain, the gains in the Gov have been tamed down so as not to cause Oscillation/chatter just incase this was the cause.

Our only Aussie distributor has been out of stock for weeks now so not sure when I will get any more gears to play with.
I might have to part with this hell/motor combo as I can't really justify $50 ago for main gears a flight.

Any suggestions would be appreciated as Im at the end of the rope now.

Cheers  Neil

[Chris Sexton]

I know many pilots running the Ultimate and I Run a 4530-500LE. No problems.

Check your gov gain. Too high can be hard on gears. But my guess is its mesh. I don't do the paper trick. I push the gear in until there is no lash at all and then pull it back out ever so slightly. You almost can't feel the lash by hand.

Another tip. Make sure the pinion is all the way down and resting on the pinion support bearing. There is a color on the pinion to help keep the main gear from flexing up with the helical forces but that ridge can't work if the pinion isn't all the way down against the support bearing. Not to mention the helical forces will trash your motor bearings fairly quick if the pinion isn't down all the way. 




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[topangler]

Hi Chris,

Thanks for the reply, Ive already checked the motor pinion is against the bearing and as in the originally post I have the Gov gain down so as not to create chatter/oscillation.

The back lash is minimal just enough to allow for expansion of the main gear and avoid binding.

Its good to know that your running a similar high torque motor with out issues.
I really don't know what else to check change fix right now.

[flyalan]

I have been running the 4530 lately with no problems. 
Out of curiosity how many main gears have you gone through? Could you post a pic of a chewed up gear on the outside chance one of us may see something amiss or something that may give a clue as to why this is happening.  Also a shot of the pinion. 
Cheers
Alan
 

[topangler]

Hello Flyalan,

I have gone through the original gear that came with the hell and also two brand new gears in the last week.

Just some background info, I bought this E7 secondhand from one of our local guys who flew the heli from new, the main gear that was on the heli was pretty worn when I bought the heli and was the first to strip, I didn't consider it a big deal as the gear was pretty worn but the heli came with a new spare main gear.
I just swapped out and rechecked backlash, fit on bearing support and Gov gain etc.

Now today I went through the third main gear.

See pics attached


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[Chris Sexton]

Change the pinion. That looks more like it was chewed up than stripped.

Matt released some hard anodized pinions. they are holding up VERY well to abuse.

[JeepCJ]

My pinion does not look like that?  Mine has a large collar on it. Is that a 12t?

Bob

[flyalan]

I also suggest a new pinion.  One of the hardened ones.  That does look like a 12T?
If you need a new main gear and cannot get one locally PM me.  I think we can get one sent to you along with a hardened pinion. I think getting a new pinion will solve your problems.

Cheers
Alan
 

[topangler]

Hi Chris,

This is the hard anodised pinion, it is dimensional integrity is sound, the picture probably makes it look far worse than it actually is.

But I will swap it out if you think thats where the problem is.

The reason for not doing this to date is because the previous pilot/owner was far harder on the heli than my current skills would allow and he didn't have any issues with gears stripping.

This would suggest its something since I took on the hell, something I've got set wrong or indeed the motor is too much for the gear train.
I am at a loss as to what tho.

Hi Bob, It is a 14T pinion, I did a lot of research into motor efficiency and power consumption before going with the 14T, I have the full set of new hardened pinions purchased before I settled on the motor choice.

Hey Alan, thank you for the offer on the main gear, I'll drop you a PM.

Guys thank you for your help and suggestions, its great to know there is somewhere to turn to get help.

[flyalan]

One last question. When did you purchase this.  The reason I ask is that I have run into someone that used an E5 pinion in an E7 with disaterous results.  He didn't bother to look close at the mesh.  If it was purchased prior to the E5 release that would be ruled out.  Just another thought...
 
Cheers
Alan

[flyalan]

Not to contradict you but the hardened pinion is not black in color.... More of a gold/bronze color.  It may just be the photo.
 
Cheers
Alan

[topangler]

Hi Alan/Chris/Bob,

My apologies please scratch the comment re the pinion in my last post, it is not the hardened pinion its the original one.
I'm not sure if the Heli was purchased prior the E5 realise but the pilot was pretty experienced and very unlikely to have given me the wrong pinion, any way to avoid doubt I'm going to swap the pinion out now for the hardened version.

I have put out a request on our local BB for a spare main gear hopefully I can buy one from a local pilot spares bin.

Fingers crossed.

[flyalan]

Keep us posted and let me know if the local route isn't available.
Cheers
Alan
 
 

[topangler]

Cheers Alan thank you so much, I'll let you know.

[topangler]

Hey Alan,

I just jumped onto the lhs website and checked out the 14T pinions for the E5 and the E7, I am pretty sure you are right in your thought process, the pinion definitely looks like the E5 pinion and not the E7 pinion.

All the new pinions I purchased for the E7 have the larger collar diameter, I'm pretty excited now that this is the cause of the gear issues I've been having, will be so glad to finally have a fix.

I guess I should have just gone with the new pinion from the start especially seeing how I already purchased them.
Ah well we live and learn.