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-   -   TBM Props? (https://www.rcuniverse.com/forum/gas-engines-142/7248364-tbm-props.html)

dmcmike 03-19-2008 07:28 AM

TBM Props?
 
Is anyone running a TBM Prop? I've got a GP Ultimate with a Brison 3.2 on it. I don't have a tach, but it seemed like when i put the TBM 22X8 on it after the Zinger Pro, the rpms actually went down noticeably, although the thing pulls like it never has before. Just curious if anyone else has noticed this?

soarrich 03-19-2008 08:09 AM

RE: TBM Props?
 
Yes, I had a Vess22a and-got 7300rpm, put a TBM 22,8 on it I got 6630rpm. One guy had over a $1000 in props, he flies IMAC and did a lot of testing, he found one engine/plane/prop combo where the TBM was best, but most of the time it was the worst, or right at the bottom.

I'm not throwing my collection of TBM props away, but I haven't found a combo that likes them.

In your case the TBM works well, that's good.

marzo91 03-19-2008 08:41 AM

RE: TBM Props?
 
Don't make a comparison just by the RPM. RPM on the ground means nothing. You said yourself it pulls better than ever with the TBM. For starters, the Zinger may be a poor choice as a baseline. The whimpy Zinger flattens out to about a 4 pitch on high RPM, so it will turn alot on the ground WOT. AS you'll see, some people don't like the TBM prop, but I understand they are supposed to be the same as a Zoar, BME, NX, and several others.

On my 50cc engines, (Brison 3.2s) I use a MSC 22x8 for the best results. They also turn the least RPM over the others. They are wide, and they load the engine a bunch.

Use what pulls the plane through the sky the best.

tim220225 03-19-2008 08:52 AM

RE: TBM Props?
 
Agreed. I was running a Menz 27/10 on my 35% Carden Edge with a DA 100. Switched to a TBM 27/10 and the DA now pulls like it never has and slows down better too. The engine seems quieter and it sure does run smoother in the mid range.

frieshoo 03-19-2008 10:24 AM

RE: TBM Props?
 
TBM props are similar to MSC, and 3W wood props. They will load any engine... However, they seem to pull very well... My DL 50 can turn a TBM 23x8 6800rpms... It will turn a Vess 23A about 7100 rpms.. I like the Vess... but the TBM is no slouch.

http://www.youtube.com/watch?v=UeigMVQ1UaA

Bob Pastorello 03-19-2008 06:48 PM

RE: TBM Props?
 
My Brison did well with a TBM like yours, until I chose an NX to let it breathe a little easier. The ULtimate did well with both, but my preference was the NX.

Zingers generally aren't looked upon with much favor, and there is almost not a less-effective prop than them, in my experience. They turn, but don't pull. The TBM's load, but DO provide a LOT of thrust. Many choose less load with more efficient prop shapes like the NX or Xoar, which seem to do well also.

tim220225 03-19-2008 07:54 PM

RE: TBM Props?
 
Gotta disagree. My TBM loads and pulls my 31 pound plane straight up with no trouble.

Bob Pastorello 03-19-2008 07:57 PM

RE: TBM Props?
 


ORIGINAL: tim220225

Gotta disagree. My TBM loads and pulls my 31 pound plane straight up with no trouble.
Okay - but this is what I wrote "The TBM's load, but DO provide a LOT of thrust. "

We don't have to agree and that's just fine.

tim220225 03-19-2008 08:34 PM

RE: TBM Props?
 
Oops, misread your post. [X(]

Tired Old Man 03-19-2008 09:07 PM

RE: TBM Props?
 
Funny thing about the TBM prop. It's not similar to a Xoar, Wild Hare, BME. Not similar at all. It's exactly the same. Xoar makes propellers for quite a few companies and most of them start out with exactly the same shapes and contours. The only difference will be the name on the front of the blade. Once in a great while one company will want a tip shape a little different to stand out from the crowd. This is where I've gotten quite a kick out of some people that have posted about the terrible results they had with a TBM prop, while stating they had much better performance with a Xoar or BME. They were flying the same prop with all of them.

It's already been noted but worth saying again. It's not how many rpm a prop provides, it's in how the rpm is delivered to the airframe. Ther are quite a few propellers that will never match the screamers in rpm counts but will otherwise out perform those props in every other way imaginable. Just like in drag mile racing. You may have more horse power but if you get beat to the finish line by someone with less how much did the extra h.p. matter? It's all in the delivery.

Bob Pastorello 03-19-2008 09:13 PM

RE: TBM Props?
 
Pat, as much as I respect your knowledge.... there is absolutely NO way that my TBM 22 x 8 is the same prop as the Xoar or NX 22 x 8's that I ran back to back. On the same engine, just minutes apart, same stated pitch and diameter, and they were completely different.

I don't expect you to believe my results, and that's fine, too.

But - you can't say that I ran the exact same prop when I ran those three back to back with markedly different results with each. They simply ARE NOT the same.

At least MINE were not.

soarrich 03-19-2008 09:51 PM

RE: TBM Props?
 
Bob's correct. They are not the same prop, the TBM is about twice as thick of airfoil as a JXF, which is a Xoar. I showed mine to LS Larry he couldn't believe the difference, VERY different props. I called and ask TBM if they had a problem with their props, like maybe mislabeled, they said no. My Brillelle 366GT would only turn the TBM 6630 rpm, I was going to call Scott for help but decided to try a Vess 22A on it ,I got7300 rpm right away.

Tired Old Man 03-19-2008 10:42 PM

RE: TBM Props?
 
I have a TBM, Wild Hare, Xoar, and NX out in the shop in 22-8 size. A mix of others in 27 and 28-10 sizes. I cannot for the life of me find a difference between them. Perhaps TBM has more than one maker doing their props?

From personal experience I don't much care for the smaller Xoars, say 22", but the 27" Xoars work pretty well.

drbenz 04-26-2009 02:38 PM

RE: TBM Props?
 
In response to the original post by dmcmike, I have several Brison 3.2's and they seem to reallly lilke the TBM 21x8. If I use a Xoar I will use a 22x8.

Tired Old Man 04-26-2009 05:27 PM

RE: TBM Props?
 
I stand corrected on the TBM. I tried one on a Taurus 3.2 mated to a 28% v2 W/H Edge. Same day and plane I tried out a Vess 22a, Menz 22-8, Xoar 22-10, and NX 22-8. The NX did the best, the TBM the worst. Never did an rpm check, just level, vertical, downline, and hover performance.

BTerry 04-27-2009 11:42 AM

RE: TBM Props?
 
Pat,

It is my understanding the TBM props are made by TZB, and not by JXF (who makes all the other props you mentioned). Your results bear this out.

thevirginian 04-27-2009 11:46 AM

RE: TBM Props?
 


ORIGINAL: soarrich

Yes, I had a Vess22a and-got 7300rpm, put a TBM 22,8 on it I got 6630rpm. One guy had over a $1000 in props, he flies IMAC and did a lot of testing, he found one engine/plane/prop combo where the TBM was best, but most of the time it was the worst, or right at the bottom.

I'm not throwing my collection of TBM props away, but I haven't found a combo that likes them.

In your case the TBM works well, that's good.
I can only verify this statement 100%. I also had the exact same numbers with my DL-50. The only difference was I ran a 22x10 and the RPMs dropped from 7300 down to 6400[X(].


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