TD pusher prop?

batjac Tue Sep 29, 2020 4:07 am

I just made up a TD.051 with a left-hand crank, and I have a second left-hand crank to throw into a TD.049. That'll give me two sets of engines to run in twins. But I can't find suitable pusher props. I bought the Master Airscrew 5x3 pusher and tractor 3-blade props, but they seem more like an electric prop than an I.C. prop. The package doesn't say electric only, and the MA website doesn't say that either. But the props just seem awfully flimsy. Anyone know where I can find matching tractor and pusher props for a TD?

The Questing Mark

getback Tue Sep 29, 2020 6:54 am

https://coxengines.ca/cox-.049-propeller-left-hand-pusher-5-x-3.5.html I didnt know till now that EX carrys Rev ups and Zingers ! No Pushers . http://www.exmodelengines.com/home.php?cat=257&sort=orderby&sort_direction=0&page=1 https://www.masterairscrew.com/collections/all-products/products/3-blade-5x3-propeller-rev-pusher has 3 bld. ... Very Happy

https://www.google.com/search?q=pusher+propeller&sxsrf=ALeKk02wnpZp_s7ewg9QpgUujVeA0IG2UQ:1601380227543&source=lnms&tbm=shop&sa=X&ved=2ahUKEwjCqvOcpo7sAhXNpnIEHYmlBbIQ_AUoAXoECB0QAw&biw=1493&bih=776&dpr=1.13

roddie Tue Sep 29, 2020 8:04 pm

I bought some "DAL" brand propellers for quad-copters.. because their design has more "hub-reinforcement" as well as testimonial to be safe for IC engine use.

I bought sets of their 2-blade 5 X 4's which include X2 R/H propellers and X2 L/H propellers. (ala-quad set-up)

Mark.. they didn't cost an arm and a leg...

This TeeDee style spinner works with my electric-starter.

Consider ordering X2.. which gives you X4 L/H props and X4 R/H props.. a good all-around size for sport-flying.

batjac Tue Sep 29, 2020 10:49 pm

Eric, I have the MA 3-blade props, but they seem too flimsy. I also have plenty of the Cox 3-blade props, but I’m not sure if they handle TD speeds well. I only found one reference to using a Cox 3-bladed prop with a TD, but the poster never said what results he had, only that he was going to try it. Besides, I’ve always wondered how the thrust differs between the pusher and tractor 3-bladers. Rev Up props are no longer being made, and anyone selling them are liquidating on hand stock, so no pushers in the range I want. Zinger has pushers, but the smallest is 7x3½ size, and I have to buy a pack of six. So I’d have to buy six pusher and six tractor, and then cut down the props to the size I want. I have the Zinger webpage bookmarked as a last resort. APC is no help at all, even if I wanted to cut down a prop.

Roddie, I wasn’t looking at quad props, as they’re usually just rated for electric motors. Those prop hubs look a lot like the Cox designs for the 4" props. Looking at the DAL props website, I like that the props come in yellow, as I like high visibility props. Have you flown these yet? What engine did you get these for? Where did you see then testimonials? I guess I’ll order a couple of sets to see how they work for me.

The Slimer Mark

roddie Wed Sep 30, 2020 7:42 pm

batjac wrote:

Roddie, I wasn’t looking at quad props, as they’re usually just rated for electric motors. Those prop hubs look a lot like the Cox designs for the 4" props. Looking at the DAL props website, I like that the props come in yellow, as I like high visibility props. Have you flown these yet? What engine did you get these for? Where did you see then testimonials? I guess I’ll order a couple of sets to see how they work for me.

The Slimer Mark

Hi Mark, Good to hear from you. I have not flown using the DAL propellers. I bought the 5040 sets to try on my .049 glow engines (Cox engines mainly) after reading a statement made by a DAL company representative, that their propeller "hub-design" will support running on an IC engine. I can't recall where I read that testimonial though.

Getting back to your OP; I'm curious to know of your twin pusher-engine model.. Popcorn

I liked the idea of having some 5" X 4" L/H props to try on C/L airplanes set up for them. The reed-valve engines; of which I have a few.. would be candidates. The outward-induced torque-roll helps line-tension. The airplanes would not require as much (if any at all..) thrust or rudder offset. The 5" X 4" is a good all-around size. As you know; I like to design my own airplanes.. and have wanted to design one around Cox's 6" X 2" that was specific to their prolific PT19 Flight-Trainer. Those props were once plentiful but they're getting harder to find.

The DAL 5040 is a 2-blade prop that looks like a comparable-size Cox black prop.

I more recently purchased packs of DAL Cyclone T5046C Pro 3-blade which are designated as 5" X 4"/6" X 3" size.. What?