Mini-500 MRGB Thoughts/Findings/Solutions

Hawk

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Francois,
I could go on and on with the problems with the mini in its original configuration. The frame had design flaws that were unrepairable with “patches”. The only fix was starting over with a new frame. The MRT is a joke! Short of installing a different Trans there is no good fix for it, only “patching”? We did what we could to it to make it serviceable for our application and to date is working, though it needs to be constantly inspected and the TBO is yet to be determined. If it had, “good gears”, an inner pinion support bearing, a true pinion carrier asm and a case that separated other than at the load centerline (like the 269 MRT & TRT) it would have been a good unit. The same goes for the TRT! This is what happens when a draftsman and not an engineer designs helicopters!!
I believe these pictures will speak for theirself!
 

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hillberg

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Winter rearends used by Kiss do not nave the nose bearing & don't assume, break out a catalog or the right gear box type & look, pull you shoe out of your mouth before you think I stepped in it. Your dream started as Dennis Fetters reality, & not from scratch.
 

HobbyCAD

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John, you are being such an idiot. Call me names, no hassles, threaten me when we meet in person, no problem, but stop showing your lack of insight into this matter. Take a chill pill mate, stop ranting and raving, you are your own worse enemy. Post only facts, not personal issues.

Rick, come on mate, show some intelligence here. That transmission you have a picture of, why does it have a front pinion support? It's a totally different bearing configuration than the Mini-500. Your picture transmission has only one rear pinion bearing, so it needs a second one up front. Look at the thin pinion shaft, it relies on the dual bearing setup. In the Mini-500, the pinion shaft is as thick as my dick, and it is supported by 2 pinion bearings. The overhang from the front bearing is zero, there is no room for the pinion to bend down, as John thinks it does. It is adequately supported, it does not require a front bearing support.

When you 2 guys want to argue a fact, you need to compare apples with apples. Do your homework before you challenge the community.

Cheers,

F.
 
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HobbyCAD

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Someone (I think it was him) made an oil screw pump in between the pinion bearings that was so effective, it blew out the seals everywhere. He's probably got that fixed now.
Bryan, I cannot take the full credit for this oil pump. I thought of it, after seeing Stan had plumbing into his transmission. It made me think, so I conjured up the idea of implementing an integral pump. I discussed my idea of a worm gear with Dennis, and to my surprise, learned that the same worm gear mod had been implemented into the Voyager transmission. My idea was thus a resurrection of Dennis's idea.

I have not yet machined my worm gear, I had to work out the amount of spirals. My idea was to put in 2 complete spirals, then machine the outer diameter down until a comfortable pump rate is reached. Luciano offered to do this. On his first try, he had such an efficient pump, whilst his outflow was restricted, he blew the rear pinion seal out of the transmission. We were thus on the right track. I am going to have a good outflow circulating through an external cooler, whilst ensuring I have a very low back pressure in the pump chamber. A small portion will be tapped off before it returns to the transmission reservoir, and plumbed to drip onto the top bearing.

Cheers,

Francois
 

Hawk

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Francois,

Better look again! There are two taper roller bearings supporting the pinion shaft outboard within the "pill" and an cylindrical roller bearing inboard. Without the inboard bearing to attenuate the flexing the pinion gear will try to flex out away from the ring gear under loading regardless of the outboard bearing layout like the Chevy 10 bolt, Dodge 8", VW Bug (this is were the original mini gears come from) and a slew of other 90 degree gearboxes. The ones that last are of the inner pinion supporting layout.
 

bryancobb

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Fact!

If the case and bearing arrangement can HOLD the geometry between the ring and pinion, so that the gears operate within manufacturer specs, when under load, it will work. It doesn't matter if there's one, two, or 16 bearings.
 

hillberg

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In Franks R-22 he removed the plane roller & went with Taper rollers on both ends of the Quill & taper rollers top & bottom of the carrier , the only ball bearing was an anti whip preeload for the top of the mast as it poked out the top (under the swashplate support.)
In some hilabrand & winter rearends you had a plug to screw in the banjo cover so the ring gear wouldn't skip teeth.
The 269 was designed for torque loads only no lift loads (fret liner inspection was a pain)
 

MH1FLYER

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Hillberg,

You still need to wake up and smell what you’re stepping in!! I just went thru all the Winter rear end catalogs and they only make a couple rear ends with no front bearing support and I would never use any of them in a helicopter, EVER!!! Kiss, more power to them hope it all works out for them but that’s not for me. Oh that guy, he stole everything he ever created, everything and that’s a fact!! Once again I would never use a gearbox without a front pinion support period in a helicopter. I’m disappointed in your lack of knowledge on gear boxes!! Here’s a link people look for your self’s. I tried to upload all three catalogs but it the files were too big.


http://www.wintersperformance.com/catalogs.htm


Hobbycad
You’re an idiot that’s all I got to say!!! A complete idiot!!! What you said about Rick made me reply this way. Now I know why I quit making post here, it’s just plain and simply useless. I’ll go fly, and you guys can go figure out how to build something correct..
 

hillberg

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The Illistrations are in error as you see them, Try opening the rearend up 1st hand. the banjo covers & main housings are cast without your nose bearing ( the serial number is normaly etched on the flat end of the pinoin. Nice try though,Sprints & Midget dirt cars were a staple at the Hillberg home over 75 years,(lots of rearends)From 1995 Kiss has sold over 100 kits with 40 or so flying the only problem in the rearend was 1 ring gear that had not been reworked after heat treat & lost a tooth. I have all those catalogs in hard cover & the other stuff is great for home built helicopters, The Mc 1 also used a gear box with out that nose pinoin bearing. It's just different ,Never limit what can work, It might save your beacon some day, When you're bringing home the beacon.
 

birdy

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John Morgan the CH-7 dose just that.
They have a small oil pump that sucks out the bottom case, through a filter and cooler, then back into the top of the mast.
 

HobbyCAD

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Hobbycad
You’re an idiot that’s all I got to say!!! A complete idiot!!! What you said about Rick made me reply this way. Now I know why I quit making post here, it’s just plain and simply useless.
It amazes me how you are allowing us to see your insecurity, by having to resort to slinging such keyboard insults at me, to feel empowered .....

Merry Christmas John.
 

MH1FLYER

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Hillberg,

Those illustrations are correct.. A friendly argument is always good, don’t you think!! That is what we will be using in the future for transmissions. They really have great products and there is no reason to reinvent the wheel.

Merry Christmas Don..


Francois

Last I remember I just made a post about facts, and you came back in post 31 and called what I said utter hogwash and went on with that babbling bull **** again. So who slang key board bashing first here??????????????? Wasn’t me I never called you out on anything. All I was doing was answering nowingsattached question about how much this transmission could take. Honest question got an honest answer from me. You act as if I caused all these problems. Those problems happened long before I ever got involved here. All we have tried to do was fix things and move on, you know go fly have fun!!! But several here just want frickin let the past rest!!!!! Shut up and fly as Ron would say..

Merry Christmas Francois..
Enjoy

American Stuffers Fly By - YouTube
 

bryancobb

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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.
 

hillberg

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A good debate has it's use in advancing the arts, Lots of goodies out to use in our toys.
Just never tell the venders that you're using the parts your buying on things that fly.
(The legal cubical hamsters just go bat sh*t crazy)
 

birdy

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Yeh, got the missus to get sum new wheel bearings for the gyro once, she mistakenly said they were for a gyro.
She never got them. :(
 

MH1FLYER

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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 will make a video to show how we do the transmissions tomorrow, and post it for everyone to see. I was very busy today and haven’t had time to reply. Plus if it’s nice, I plan on flying it. That’s why I have worked so hard to get here!!
 
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