Will a Dynathrust prop ruin my Zenoah engine ? The Dynathrust props are a bit more flexible than wood and APC props.... ok maybe a lot more flexible [X(] I remember someone telling me once that a prop that flexes in flight can ruin the bearings in an engine Is this true ????

I know Dynathrust props suck, and that they tend to throw blades, but I just got a new G-45 and put it on a new airplane I jsut finished I really want to test fly this plane tomorrow and the only prop I have at the moment is a Dynathrust 20x8 [:@] , and for a the test flights the dynathrust would be perfect as I dont mind if it gets broken I just need to know if using that prop is going to harm my engine ????

Sorta like a Master Airscrew, huh?

Never heard that. Can you or anyone else back it up?

Never heard that, either. Same question.

Dr.1

I don't think it will hurt your engine in a flight for a couple of flights unless you are unlucky enough to smack the prop on the ground or throw a blade, but you already know the danger there. With a prop that is more resistant to breaking than a wooden prop here is the problem. When you hit the ground with it you want the prop to shatter because if it doesn't the front part of the engine will stop turning before the back part does. This can cause the rear of the crank shaft to twist on the crank pin. Two options would be to send the engine to RCIGN1 for repair or buy another crank and replace it yourself.

Although a wooden prop acts like a fuse, it is still no guarantee but better than a Dynathrust. Make sure the Dynathrust is balanced and get it off of your engine as soon as possible. Don't throw it away, they are great for stirring paint.

I wish somebody made a carbon prop that had the same blade design as the Dyna-Bust. It's a perfect scale prop for my BirdDog, so I'll keep it for display, but what a PITA to have to change to a decent prop for flying. (ZDZ 50, 22-10 prop)

I have a 1/3 Spacewalker with an OS 300 twin for power - I have been flying it for 14 years - with a Dynatrhust 20x8 prop. So figure maybe 5 gallons of gas a year - 14 years - 70 gallons of fuel thru it with this evil Dynathrus prop and never a problem with the engine. I don't know what has been said about Dynathrust props, but after this much time and no problems - I can't say that it really is an evil prop.

Dan

Glad you hear its worked for you RC100. I had the same kind of stoy with my 1/4 scale cub and a G-38 with a dynathrust prop. I flew the heck out of it for years, whacked the prop on the paved runway more times than I care to admit, sanded out the knicks, even a giant one, and it kept on flying I was poor and couldnt afford to buy props that would break [X(]

That being said, I have read of so many stories of Dynathrust props breaking that it scares me. I mean LOTS of em [:'(] They are also not that efficient, so now that I can afford it I will get carbon fiber or APC props that are able to transform more horsepower into thrust That prop is in the mail, but in the meantime, I want to test fly my plane now and have a dynathrust I was using for stirring paint that I can throw on there

been using Dynathrust for yrs. too. Don't you think if they were ruining engines they would be still in business? Use it and enjoy it.

No, I don't believe that the Dynathrust prop will harm your engine, providing it is properly balanced. I have seen lots of them perform flawlessly. On the other hand, I have seen a few of them throw blades in flight. That's the problem I have with Dynathrust props - you just can't be sure when or if it will happen.

In the instances that I know about, when the blades separated, it tore the engines right out of the airplanes, and they obviously crashed. However, I don't know of any time that anyone got hurt from a flying blade.

When I was in business, selling those props, I quickly made the decision to not sell them any longer, knowing that they weren't 100% safe. I was afraid of being sued big time if someone purchased a prop from me and got hurt, or hurt someone else. When I get the time, and providing I can still find it, there was a big article in High Flight telling about Dynathrust blade separation, and advising everyone to be concerned.

You do what you have to do, but like the man says - Dynathrust props make really good paint sticks. I wouldn't put one on my airplane, no way!

Murphy's law applies here, just like everywhere else
I was running a G62 on a test stand with a NEW 22-10 Zinger prop, never used on an airplane. It was bolted TIGHTLY on the engine...It broke when I brought the rpm up...
Sent it back to Zinger, no reply other than they sent me 2 new 22-10s...
Apc made some 3 piece props, a metal center with replaceable blades..A few came apart, they quit selling the props..

Bolting it to TIGHTLY can cause a failure at the hub RCIGN1 [X(] Where did your prop break ? Tighten them so they dont come off but overtightening does very bad things [:@]

I test flew my G-45 and plane today with the evil Dynathrust prop [>:] The engine performed flawlessly Started right up by hand every time, didnt quit once, and I didnt heave to touch the needle valves from the recommended setting in the book. It ran rich but good, which is what I wanted for break in. It would idle so low I finally had to use the kill switch because it just kept ticking away at lowest throttle setting I was careful not to develop to many RPM's on the prop (no power dives). I am very very happy with the engine and the prop stayed in one piece

Been bolting props TIGHTLY on to G62s for 18 years, never had a failure at the hub or had one come loose...I always take the 2 roll pins out so the props have only the center hole...The blade broke off about 3 inches from the center, well away from the hub...There was no indication of anything wrong with the wood, must have been a bad piece...

Ahh, I missed the fact that it was wood !!! They are much more tolerant of overtightening than glass and carbon. They say the compressive loads in glass and carbon caused by overtightening can cause failure, although I have never tried this myself

What did it do to the engine ? Did it hurt it ? Did it come out of your stand ? I bet that blade shot like a bullet wherever it went [X(]