Mr67Stang

Okay I just broke in the motor for my little 1/2a trainer-like plane. It feels a bit heavy to me for its meager 30in spand and about 5 in chord. so I have about 140 sq inches of wing area when you subtract the part obstructed by the fuse. I think the wing is going to be overloaded but I do not have a scale to figure the actual loading (hmm post office???) Well according to my digi tach my little AP .061 Wasp was spinning an APC 6x3 up to 31k RPM with good throttle response (transition) I am thinking about putting my APC 7x3 on. I also have a MAS 9x6 but I think that would be way to much prop. What would you use?

Larry Driskill

I would start with the 6X3.

I have had an APC 7X3 on my Norvel .074 and it appears about right for that engine.

I suspect the 7X3 would be a load on the .061.

combatpigg

My Feedback: (3)

Man, those AP WASP engines are getting stronger! Mine only turns a 6x3 in the 17,000 realm.

Andrew

That's pretty stout for an AP -- I usually view a 6x3 as about the maximum for these engines, unless they're being overpropped for a Texaco style competition. 9x6 is way out of line and I agree with Larry that 7x3 would likely be too much.

You might try a 6x3 MAS -- blade area is a little higher than the APC.

Mr67Stang

This is my first "small" engine. I have no idea what to expect from it. Also if you reread my original post I intentionally wrote it to express my distrust in the Tachometer reading. So your numbers are helpful to show me what is probably more accurate. maybe I am not using the tach properly? I am ensuring light is shining on the blades and holding the tach about 5-6 inches from the prop. I am also ensuring it is set to 2 blade. Any other technique?

eroc144

My Feedback: (1)

Sounds like you're using the tach correctly. Sometimes I'll shine a flashlight into the prop while taking a tach reading - Seems to help when I'm in the garage. The readings on my tach jump around a bit (8k, then 12k then 18, then 3k, etc) but they usually settle or at least repeat around one number, and that's what I'll use as the reading.

I normally use a 6x3 APC on my Norvel .061 Big Mig and it turns around 17.5. My Norvel .061 CL turns a 7x3 APC at around 15.4k.

EG

flyinrog

My Feedback: (1)

Man I thought that was high too.(31,000 where do I get one!!!)..my little hobbico tach worked great for about 4 months, now it jumps all over the place...6 x 3 is all you want on that engine...you might be ok with 7 x 3 since its a trainer , but I wouldnt bother...maybe both of our tachs need new batteries?....since your new to the little ones..the term "texaco" is about slowing an engine down with a larger prop to make the tank last longer to keep the plane flying/climbing longer..I am not sure but I believe it is a free flight (no radio) event...Rog

BANJOAIRPLANE

If you are taking tach readings in a shed or building with flourescent lighting expect to get some interference.That is how you check your tach,by the way for accuracy,hold it up to a flourescent light.

eroc144

My Feedback: (1)

Really? How many RPMs does a fluorescent fixure turn?

BANJOAIRPLANE

I'll have to check my manual,but it does have a set amount of rpms,lol.

eroc144

My Feedback: (1)

Kidding aside, fluorescent lights do cycle on and off and at a very high frequency - kinda like a strobe light. My shop lights "tach" at 3600 for 2 blade, 2400 for 3 blade. The RPM number doesn't vary at all, and I'll guess that means that my tach is just fine!

EG

tangerine-jack

I've been exploring the Texaco arena and I've found two ways of doing it, one is strictly free flight, the other is "radio assist". some of the free flight Texacos went out of sight after 30 minutes or more after a 15 second engine run (and were lost), radio assist flights are limited to 15 minutes. I'm looking into purchasing my first Texaco legal flyer in the next week or so, it sounds like a lot of fun.

flyinrog

My Feedback: (1)

free flight isnt allowed at either of our fields..[]

BANJOAIRPLANE

I don't know Rog,I seen one of Donnies planes fly off.It looked to me it was FREE!

tangerine-jack

I don't like the idea of my airplane flying off into the sunset, so I will be using the radio assist (I think it's rudder only, but I'm not sure). In any case, this thread is being very helpful!

Mr67Stang

Does this mean I have to look like I'm actually in control of my model? Hmm... this could be a probplem.

Mr67Stang

Okay, I have flown this little bird and had a beauty of a day to do it. Rog, you've seen the video. Well with PROPER daylight I believe my tach readings worked out a little better. I showwed a 15,500 RPM a WOT.