The Prater Machine

Lspav8r

Senior Member only in age
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Feb 28, 2009
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502
Location
Beaver Dam, Wisconsin
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Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
As some of you know by now, I purchased the Prater Machine last year from Dave so he could travel around the country and enjoy his retirement. After getting her home, she spent the first winter in my finished basement so I could look at it in a heated environment any time I wanted to.

Got it out and put it in the garage when the weather permitted, and dragged it to events this year and untill today I never even started it.

To be honest I took it to the differant events to trade it for an ultralight two place and I even had something lined up, but then that fell thru so I decided to keep the gyro and make the necessary changes to make it more newbie friendly, such as change that narrow gear to the more user friendly wide stance gear.

Went to the airport and bought 5 gallons of 100LL and mixed up a batch.

Got it out of the garage and put a gallon in the seat and proceeded to fire that thing up for the first itme since purchasing it. Man what a feeling hand proping that thing to life for a little run time to lube everything up.

Found a leak in the inlet to the secondary fuel pump so new hose and clamps are in store for her.

I almost forgot. I changed the paint scheme some from Daves old one to Stars and Red White and Blue Tail feathers.

Pics to follow as soon as I figure out how to post them.
 

jcarleto

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Jim,

Just an aside...In a previous thread it was mentioned that platinum points and a well-charged magneto were two keys to good MAC ignition. You might care to know that Dave Prater had his own magneto recharger. You can reasonably tick off the box for "well-charged magneto," as lack of charge on that machine is not likely due to the reasonably certainty its magnetos were regularly recharged.

I have to say that was among the best running MAC engines I have ever heard run.
 

C. Beaty

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Tungsten, the normal stuff of ignition points, forms insulating oxides in the presence of air and moisture. No problem, automotive ignition systems with 12 volts on tap would burn through the oxide.

The Mac magneto, with the rotor spinning at running speed in a lathe, only made 3 or 4 volts open circuit, not enough to punch through the oxide layer of tungsten.

Platinum, like gold and other noble metals, forms no oxides.

I found that Eisemann platinum points would fit a Mac magneto if a slightly oversize drill was run through the fiber bushed pivot hole. I think also that the adjustment slot had to be slightly elongated but perhaps not; it’s been 35 years since I last played with a Mac.

I bought a set from the Florida Eisemann dealer and they solved all of the Mac starting problems. When I heard they were going out of business, I bought all the points he had in stock, a dozen or so sets and made them available to whomever needed a set at my cost, ~$12 as nearly as I can recall.

Dave Prater bought my last set.

Capacitive discharge ignition is fine with its ability to fire what would normally be fouled spark plugs but a box full of electronics can never equal the simplicity and reliability of a magneto.
 

Rick Whittridge

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Dec 30, 2003
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Ohio
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Capacitive discharge ignition is fine with its ability to fire what would normally be fouled spark plugs but a box full of electronics can never equal the simplicity and reliability of a magneto

Unless you have the Best of Both Worlds!
 

Attachments

Gyro28866

David McCutchen
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Be mindfull that static ground runs, will build a lot of heat.
 

Lspav8r

Senior Member only in age
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Messages
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Location
Beaver Dam, Wisconsin
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Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
My head is getting too big from absorbing all this valuable Mac information. Thanks for the input you guys.
 

animal

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Jim thanks for starting this new thread.
I am sure you and many others will gain a lot from it.

hope to see a few pics soon.

as for posting a pic, go to manage attachements select the photo,then click on upload.
 

Lspav8r

Senior Member only in age
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Feb 28, 2009
Messages
502
Location
Beaver Dam, Wisconsin
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Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
I have decided that I will pay ohmage to Dave Prater and his contribution to the sport by having "The Prater Machine" on the tail feathers of his old machine. And I kinda like refering to it as the Prater Machine as well so I shall always refer to it in my posts on the forum if its okay with you guys. I think its the least I can do since he is out of the sport so to speak.
 

animal

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I have decided that I will pay ohmage to Dave Prater and his contribution to the sport by having "The Prater Machine" on the tail feathers of his old machine. And I kinda like refering to it as the Prater Machine as well so I shall always refer to it in my posts on the forum if its okay with you guys. I think its the least I can do since he is out of the sport so to speak.
Dave and that machine was a legend at the fly-ins he was well known as the alarm clock as he would fly low over the camp grounds first thing in the mornings waking up all the campers.

I think that would be a fitting tribute to him and the machine.
 

PW_Plack

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I have decided that I will pay ohmage to Dave Prater and his contribution to the sport by having "The Prater Machine" on the tail feathers of his old machine...
Or maybe a graphic of a bouncing alarm clock. That way the newbies would ask about the story!
 

Lspav8r

Senior Member only in age
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Feb 28, 2009
Messages
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Location
Beaver Dam, Wisconsin
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Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
I like it.

I like it.

Or maybe a graphic of a bouncing alarm clock. That way the newbies would ask about the story!
Perhaps an alarm clock with rotorblades on it, and big tuned pipes. I will work on that one.
 

Lspav8r

Senior Member only in age
Joined
Feb 28, 2009
Messages
502
Location
Beaver Dam, Wisconsin
Aircraft
Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
Well, as you guys can see I suck at getting pics on here and in the right place.
 

Lspav8r

Senior Member only in age
Joined
Feb 28, 2009
Messages
502
Location
Beaver Dam, Wisconsin
Aircraft
Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
I am in the process of figuring out how to raise the seat tank on the Prater Machine somewhere around 4 inches and am not sure how to go about it. I have purchased 1 inch angle and 3/4 inch angle to do the change but just have to visualize how I am going to make the change.

I could take pics of what I have but honestly I do not know how to interpret the process for posting them from the instructions I recieved online here. Anyways, give me a little time to figure this out and I will post pics.

I know that the KB2 is stock construction as it stands so if someone has plans they can see what I might have to do to raise the seat.

I had a set of KB plans on my pc but lost all that stuff when I had to reinstall Windows, and Gyrowiki is down so I cant get any plans off of there till they are back up.
 

Gyro28866

David McCutchen
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Dickson, Tn. USA
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Benson B7m & B8m, Dominator II; Kolb Mark III Classic
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What is that going to do to the Flight Characteristics????????????
Before you do any mods, consult with some of the more experienced "bensen" flyers around here!
 
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Lspav8r

Senior Member only in age
Joined
Feb 28, 2009
Messages
502
Location
Beaver Dam, Wisconsin
Aircraft
Nothing at this time, but I think the daughter and I are gonna get us a 2 place helicopter.
Total Flight Time
600+
Well,

Without naming names, I was told by someone who has been flying Bensens for a long time that if the seat was raised then the machine would be less unstable.

I would appreciate any input regarding this so I can evaluate all the options before taking the ole Prater Machine apart to make the changes suggested.

I have already changed the landing gear to the wide stance for stability on the ground and now I am looking for ways to make the machine more newbie friendly, as I am not too crazy about having to learn that it is a highly maneuverable machine more than I care to maneuver. Did that make any sense?

I have watched guys like Gary Goldsberry fly his (which is the same machine), and it is really a dirtbike in the sky. I want to ride a Goldwing not a Husqvarna:) I guess what im trying to say is I dont really want to have to master balancing a ball on a pinhead to be able to fly. I have been told that the machine flies like a cub, and that would suit me just fine, but man that thing really is wild when Gary flies it.
 

C. Beaty

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Dave Prater’s Bensen with seat tank and light weight wheels is as near to CLT as possible. I measured it at ROC years ago.

The only modification I can suggest is to install a sizable “T” tail to damp out the friskiness.
 

gyromike

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Abbeville, Louisiana
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Bensen B8MG
Jim,

A Brock/Bensen with a seat tank and lightweight aluminum wheels should be close to CLT. I have basically the same machine as you do and it is within 1/2" of CLT.

If you want make it more stable put a Ron Herron T-tail on it:
http://www.littlewingautogyro.com/tail.html

Just sliding my butterfly rockguard back to the tailwheel made a difference.

As for hot-rodding, that's what the throttle and cyclic are for. I can fly mine nice and easy, or balls to the wall.
 
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