Mini-500 MRGB Thoughts/Findings/Solutions

[scott heger]

Does a Mini 500 have a transmission temperature gauge in it? Seems like this would tell a lot about some of the MRT issues it has.

Scott Heger, Laguna Niguel,Ca N86SH

 

[bryancobb]

Scott,

In the stock setup...no temperature indicator. Mine will have one that reads oil temp on the EIS.

 

[MH1FLYER]

John,
I consider you a friend. You have helped me out and I hope that will continue.

But, Are you not currently flying a Mini-500 MRGB on your 120HP ship? What design changes/updates have you included?

It doesn't have an oil circulation and cooling mod, does it? How's it performing??
It doesn't have a pilot bearing on the nose of the pinion does it?

I know it DOES have gears that YOU had heat-treated. You have never posted scans of the QC documents where they were tempered or what specifications you directed the heat treater to follow. Those sure would be enlightening to us.

Bryan,
I hope this will give you a good look at how we upgrade them to make them safe to fly. I will do more videos of Jessy’s transmission going back together from start to finish and post those as well. Looking forward to flying mine again in the next day or so!! Merry Christmas all!!!!!!!!!!!!!


Transmission Plumbing - YouTube

 

[bryancobb]

Merry Christmas John!

Just finished Santa Duty and HAD to get a helicopter "fix." There is no doubt that your mods help. They are simple, easy to do upgrades that seem to have been doing well for you.

One thing that jumps out at me is the oil cooler should be in the radiator cooling shroud so it can benefit from better heat transfer.

I have some specific questions about Jesse's gearbox:
* How tightly did the upper and lower mast seals fit in the case?
* Did you get a hardness test report before deciding what to do about heat treat?
* Did you measure "as-shipped" preload on the mast beaarings? What was it?

 

[MH1FLYER]

Bryan

Oil cooler!!! Gets a lot more air than you think, the picture can be miss leading you know. A lot of air from the fans blows right thru it. Then it hits the fire wall and goes up and out now. With the pluming we are doing and the Trans getting the proper oiling, it doesn’t take much air to keep it cool. It just don’t get as hot as it did before now which is good. That’s how it’s supposed to be right???


The seals on Jessy’s transmission have a great press fit. We still do the tabs for backup some tend to move in and out like mine did, poor fitting.


We have everyone tested before we do anything. So far none have passed, as I have said here many many times…. By the way, the ring gear is an RC of 54 and the pinion is an RC of 56 now.



No!!! Not going to waste my time checking. All I care about is what it is when it goes back together…


As you know it was like yours, a zero time transmission and it had to come apart to do all the mast support upgrades anyway.


If it’s as nice tomorrow as it was today I’m going to get a real helicopter fix called go fly!!


Merry Christmas Bryan..

 

[bryancobb]

Merry Christmas, John.

 

[MH1FLYER]

Helicopter fix won by Rick today!!!! Way to go bro!!!!!


https://vimeo.com/82693097

 

[NoWingsAttached]

Greg,

Come over and look at my brand new project one. I will finish it, get the airworthiness, fly off Phase I and balance the rotors and work all the bugs out. Then sell it.

It would be a great starting point for you and your intentions, or if you are not over 200#, I will prove to you that the Rotax 582 with PEP is an OK setup by demonstrating it to you as much as you'd like.

I have no interest in the engine, I need an airworthy airframe on which to install a Mohawk GT4 150hp. If bought anything with an engine on it - of any type - the first thing I would do is remove it and sell it.

I'm definitely going to be visiting you soon!

 

[firefox]

I have a two place Helicopter Rotorway Exce Complete with 63 hours of fly. but need may be inspections.. I have a few fly instrument also to install. had been in a room temperature garage. ..I will trade for a complete Mini-500 .

 

[Vance]

Good afternoon Oscar and welcome to the Rotary Wing Forum.

I have found posts are more effective if I make it clear what I want.

If I want to sell something there is a for sale forum and if I want to buy something there is a wanted forum that may be more effective for me than tagging on to other posts some of which are very out of date.

When I am looking for information I find the appropriate forum and ask.

Please complete training before you fly.

I wish you all the best on your aviation adventure.

 

[HobbyCAD]

Hi All,

At last I'm reaching the end of my build, one of the final tasks is to set up the preloads and backlash on my MRT. It seems the agreed parameters are 50in.lb preload on the mast bearings, 35in.lb on the pinion bearing, a backlash of 0.006", but the proposed parameters are supposed to be at a 200F case temp. I have no way of heating up my assembly, so I'm hoping to set it all up at room temp.

Any advise on the difference in preload, when setting up statically at room temp?

Thanks in advance for any advice.

Cheers, Francois