Need to increase power in a byron prop reduction drive.Has a Q-42. Plan to install it in a Nosen P-51. My sachs 3.2 won't work. Will a Q-75 fit the mounts? Luv that 4 blade prop.

trdpro,
I remember the Byron P51 and the prop drive from the Byron ads from the early 80's. Can you recommend a link to see the prop drive again?
Thanks R. C.

Don't know of any at this time. Engine is mounted nearly 12" back from prop and has 2 belts connecting shaft from engine to pulley directly behind prop spinner. Early drives had Q-35s and later ones had Q-42s. Was informed I need a 60cc to power this drive in a 100" mustang.

trdpo,
Thanks for the quick response. I work in a machine shop and the thought of fabricating such a drive appeals to me, so if I can find a picture, Hmmmm.
Thanks. R. C.

R.C. Day Have pics of two different drives. Can scan and email if you want. Need belts for byro drive(smaller version of reduction drive) Still think my A&M 3.2 will work as it is worth 7hp Only need to make a new rear mount and adapt shafts together. Let me know if you want pics. Thanks, Bruce.

Those 2 skinny little Gates belts slipped pretty badly with a Rossi .60 on there..You probablywon't be able to keep them tight enough with a 3.2 on the nose, much less start the engine at all...The later PurrPower had 2 mounting points and could be adapted to a Q 75 or 3.2, and would hold the weight of the larger engines much better than the little aluminum tube bolted to the light firewall....
Check out the reduction drive for a G62 on Mick Reeves' website...Way better....
One of our USRA pylon racers had a 5.8 Sachs on a Nosen P51..something that size could easily handle the 4 blade prop without any reduction drive.....
I think Iron Bay Models has pictures of the Byro drive and/or PurrPower...

You are correct. The Reeves drive is much better. Would only need to hang the byron prop on it and go. May sell the byron drive and get the Reeves. Thanks for the help.

trdpro,
Thanks for the offer, I will look for the Byro Drive and PurrPower information on line.

rcign,
As before, you are the answer man, I will look for Mick Reeves site and check out the G62 reduction drive.

Thanks for the info and help.
R. C.

Folks on other threads have said that the Byron prop blades cannot use the extra power provided by an engine larger the the Q-42; the blades apparently flatten out with more power. So what are you gentlemen planning on using for props?

Byron sold many Purr Power setups with a 4 blade prop on a 4.2 Sachs....It works....

and it worked very well...

Thanks for all the input. Was contacted by a guy in LA that has run his prop drive in front of a Q100 with no problems. Guess that pretty much answers any questions about prop strength and belt problems.

The original Byron prop drive was made for a .60 engine and used 2 little Gates V belts..It could be ordered with different diameter pulleys, depending on engine..I reworked one for a .90 SuperTigre, still not very powerful..We had one with a Gates 3/4 wide tooth belt on it, worked better because the tooth belt didn't slip..There is no way a Q100 would even fit on the original belt drive, hanging on the end of a 3/4 aluminum tube on a 1/4 firewall in a foam fuselage...the Purr Power was next, direct drive,an aluminum can with a fitting that went to the engine..It was made for the Sachs 4.2..The Purr power was mounted to the fuselage with 2 half circle mounts to 2 firewalls..This would hold a Q100 if the pipe to the can was reworked...There is no reason to use a reduction drive on a Q100 unless you are planning to put it in an ultralight..The original Quicksilver ultralights used a 100 cc Yamaha.. .A Mick Reeves belt reduction on a G62 will turn a 30 inch prop, so with a Q100 on a belt drive the prop would be too big to clear the ground...
Pictures on the Iron Bay Models website...

For months prior to when I bought my Byron Ryan back in 12/90 I clipped all the full page Byron ads from the R/C magazines, plus I still have the catalogue, the most impressive models to me were the P-51, Staggerwing and the awesome F-16!

I have twp of the Byron reduction units with the big four blade props and there is a little confusion here about the systems. The 4.2 Sachs purr power engines were direct drive and were used in the Corsair and the P-47 and the F6f Hellcat. The Corsair and the Hellcat both got three blade props and the Thunderbolt got the four blade. There were some early reduction units in the P-47 that had an idler pulley to tension the drive belts but there was a lot of problems with that system and it was discontinued. The Mustang reduction unit worked pretty well with the Quadra 42 and was under powered with the Early Quadra 35. I have the Quadra 42 and I upgraded it to the Byron Mustang 50 when it came out and Byron produced a kit to do it. It included the two support plates and the clam shell supports for the two tubes. They were made out of aliminum and not the hard plastic of the originals. The Mustang 50 definitely produced more power and spun the prop faster but the static thrust it developed was actually less than the Quadra 42 because it caused the blades to flatten out. Any speed above 3800 RPM on that prop produces less thrust and the blades are the problem. They are soft and they were built that way for survivability but that makes them very inefficient. We had a big forum topic going here a few months back on the prop design and all of the problems with it and a guy in California said he could build the blades out of Carbon Fiber and bring this prop into the modern technology we have today. Lots of guys expressed great interest in the project and then someone started saying it would be a copyright/pattent infringement and he would face a lawsuit from Iron Bay the new owners of the Byron kit line. He said he didn't need the hastle so the forum thread ended. I'm not a lawyer but I sure don't see any infringement in making a prop blade. Are Zinger or Clark or Bolly specifically licensed to produce their props. I don't think so and it just gives the modeler another choice. I don't get it. If a guy was producing that drive system as it was designed by Byron and selling that I could see the problem very clearly. I have replaced the bearings in my reduction system twice and I bought the bearings from Bearings Inc. Is that an infringement?? I buy the replacement belts directly from Gates. Is that a problem??
Making this system work focusses on upgrading a design from the mid 1970s. Prop technology has come along way in that time and it would dramatically improve the reduction system efficiency.

I'm the biggest fan of scale props there is but I know the limitations of what is curently out there and it would be impossible to direct drive a prop of this size with a 3.2 cu in motor.
I agree that the 3.2 makes good horsepower but it doesn't have the needed torque and it develops that peak horsepower through high RPM and that won't work. I don't think you could keep the blades attached to this system at 6500 RPM.

Just my two cents worth.

Jack Devine

Who was the big-mouthed weasel that had to rain on that parade? In my non-legally-educated opinion, there is plently of prior art for adjustable props, multi-blade prop systems, and plastic props to blow any infringement case completely out of the water. Of course, that never stops anyone from suing anyway, so it's still possible. Does anyone know the folks at Iron Bay? Would they actually stoop that low?

Ack, what a shame!

What a great web!!! Alot of opinions. I think a Q-42 or 50 will have more than enough power to fly a Nosen P-51 as they build light(even with extra weight of drive) Original plans show a Du-Bro prop drive with a .60 engine.(I have one of those also). Would be great also to find a modern prop which could transfer more torque like full size props can. Anyone like to try?

Based on a few month's digging, I think there's a whole lot of us that would like more scale multi-blade props, but apparently the multi-blade naysayers have convinced all the manufacturers that it's a bad idea, because there just aren't any. Besides Iron Bay, there are several European manufacturers that make pattern-style high efficiency three-blades (mostly *very* expensive), Zinger who makes a line of three and four bladed wood props with metal hubs, and Master Airscrew who make three-blades up to 16". That's it.

A buddy of mine is flying a pitts with a 3 bladed wood on a bme 102 I think it is a 26x10-3 made by NX

Darin

Both Menz and Fly-Tec makes quite cheap multiblade props. Both up to about 33in 3 and 4 blade.
Example: Menz 32x18 3-blade 97euro (about the same amount in $)
Fly-tec 33x18 3 or 4-blade 134.90euro.

So if you can live with the fact that the prop does not have the exact scale blade shape there are many sizes to choose from. How about a 28x3,5... Talk about slowfly...

http://www.hoellein.com/websites_neu/home/home.html
http://www.fly-tec-modellsport.de/we...hp?artgruppe=1

Wow, neat! Are there any pictures of these props out there someplace? Can anyone say which has the closer to scale profile?

Rick...

The only pictures I know of are the ones on Fly-Tecīs site.
Goto http://www.fly-tec-modellsport.de/ Click on Fly- Tec Holzprop and click on Bilder... There are a few pictures.
They have a picture of an adjustable pitch 4-blade prop I would love to get my hands on. Donīt see it listet though, so it may be a one-off prop.

From an engineering viewpoint why isn't it feasible or practical to build a variable pitch design? helos have swash plates, could not an affair be built? why not for the large engines and multi blade props?
Now I may not be much of a flyer if at all but I am a fabricator and a machinist, if I had a 1/4 or 1/3 scale warbird like a Corsair, P-51 it would be interesting to have first a prop reduction unit and then a variable pitch control say either an independant servo or on engine speed.

Something to consider with a bigger prop is the prop disc drag will go up considerably with a bigger prop/slower rpm. Consider a nosen p-51 with a q-100 and direct drive 24x12 prop versus a q-100 with a 2.5 to 1 belt system and a 32 to 36" 4 blade, which plane would win the race and which one would look like a real P-51. A Sachs concrete saw has a nice v belt pulley on the back and would be a good place to start for a drive system, engines are 5.8 cube also. anyone like to consider this? A 7.3 husky concrete saw with a pulley would provide even more oomph.

As far as the Q100 with propdrive, found out he made blades from carbon fiber. Am waiting for more info today,possible pics also. Hopefully he can make more blades or complete prop but who can tell. I don't believe it would break any patent laws because that Byron prop drive hasn't been made for a long time. Iron Bay may have parts for it but they don't manufacture it. Their Mustang 50 is a direct drive but they don't show a pic on their web site.