Brock Pre-Rotator

Re: Brock Pre-Rotator

I just received mine from Brock...It's a "Wonderlink?"<br><br>Brock has a deal with Great Plains for the VW engines and Wonderlink (I don't know if that's how you spell their co.) for the prerotator.<br><br>John-
 
Re: Brock Pre-Rotator

John,<br><br>At Mentone this year there was a guy there that had an older Dominator that had a drive shaft going to the rotor head.  At the engine there was either a friction wheel or a belt, I can't remember.  From there a short shaft went forward to a 90 degree gear box.  Out the top of the gear box was the drive shaft with universal joints at both ends.  The drive shaft was a 2 piece unit that would telescope as pitch input was made.  At the rotor head, there was a drive gear just like you would find on a Wenderlich system.<br><br>I had read on the other forum some time ago that this set up was a Brock drive.  I don't know if this is true or not.<br><br>Don
 
Re: Brock Pre-Rotator

Should be a standard Wunderlick, with the a belt drive to a square tube, instead of the tele-flex cable .
 
Re: Wunderlick Pre-Rotator

Re: Wunderlick Pre-Rotator

Wonderlink - no<br><br>Wenderlich - no<br><br>Wunderlick - yes<br>
 
Re: Brock Pre-Rotator

Dick Wunderlich is the man's name, according to the Ads in Rotorcraft magazine.<br>
 
Re: Brock Pre-Rotator

You know Al,<br><br>I've always been good at butchering names ;)<br><br>I'm glad yours is short ;D<br><br>As for the prerotator, I think mine is a friction wheel.  Haven't really looked at it hard, just inspected the box so far.  Next week I'll count the peanuts :D<br><br>john-
 
Re:Brock Pre-Rotator

John, are they the kind of peanuts that disolve in water? That's what Air Command uses!

C'mon I need to know more about that prerotator! How much $ ? Did you get the rotor brake? Did you change the torque tube or just drill a hole? How's that nice engine runnin' ?
 
Re:Brock Pre-Rotator

See if this pic comes out.
 

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Re:Brock Pre-Rotator

or this...
 

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Re:Brock Pre-Rotator

Worked for me. Unfortunately the old attachment links were broken with the upgrade. I apologize for the trouble.

Todd
 
Re:Brock Pre-Rotator

Yeah,

That's it! Scott, The pics look great. Your gonna make me get mine together sooooooooon.

Chris,

Engine runs fine, Have drilled anything (yet), Yes, I got the rotor Brake, under $800 for all from KBM and they installed the ring gear.

John-
 
Re:Brock Pre-Rotator

The sliding shaft prerotator is a sweet system. Richard (Catfish) Oxnam has it on his machine. I used it on two of mine.

Much cheaper too.

Dave, Thumpernator, DeWinter
 
Re:Brock Pre-Rotator

Does anyone have a picture of the sliding shaft pre-rotator system? I'd like to see exactly what you're talking about.
 
Re:Brock Pre-Rotator

the sliding shaft is a Standard upper unit as in the photos earlier in this thread, and a standard bottom or end unit as in the photos earlier. The difference is the bottom unit is mounted on a hindge to the mast and the rubber puck swings out to contact a disc welded to the front crankshaft pulley on the Subaru engines. The drive between the upper and lower units is done through a drive shaft, which is basically a two piece round tube or square tube that allows the pieces to slide up and down with the rotorheads travel. There is a universal joint at both ends so the shaft doesn't restrict rotorhead movement and so you can move the rotorhead while pre rotating. In a nut shell it is a Wunderlick with out the flex cable and a driveshaft in it's place. I have only seen these units on Subaru ea-81 powered machines.
 
Re:Brock Pre-Rotator

Scott, Your pre-rotator looks really close to the cheek plates. Is it going to make contact when you make a right turns?

Or when your put you blades on will the pre-rotator be moved back behind the mast area.

Just curious, Phil
 
Re:Brock Pre-Rotator

Dave Dewinter sent me some pictures of the sliding shaft pre-rotator. Take a look:

pr1.JPG

pr2.JPG

pre22.jpg
 
Re:Brock Pre-Rotator

Todd,

This is really close to what I saw at mentone. This one looks a lot simpler than the other one - no 90 degree gear box to deal with. Judging by the location of the friction wheel in the last image (which is a different gyro), it looks like there would be a lot of over-driving; too much RPM, not enough torque.

Don
 
Re:Brock Pre-Rotator

Yes, those pics are from two of my machines. The first from the Bensen style and the second from the Dominator (Thumpernator).

You could get well over 200rpm with that second setup.
 
Re:Brock Pre-Rotator

To answer Phil's question, YES The prerotator is close to the mast, although in the picture the stick is all the way back, and the pre rotator clears the mast, but the tele-flex drive wants to hold the head all the way back. I still have to do a hang test, and set-up the blades.
But it seemed kind of close as you mentioned.
 
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