TeeDee questions

I like the Glowplugboy for all engines with 2 copper head shims (Cox heads), but I add 1.3 ounces of castor to bring it up to 20% oil. I buy castor at the Dollar store for $1.50 in a 2 oz bottle. I like to use Sig Champion 35% in the Tee Dee, with 3 shims. It adds another good boost of RPM. It has a 50/50 mix of synthetic and castor for a total of 20% oil.

Here is a handy calculator for adding castor. If you have Excel on your computer, download it so you always have it handy:
www.coxengines.ca/files/castor.xls

Glow fuel Tee Dees are meant to run high RPM with smaller props. It will run like an ordinary Black Widow if you load it down with a 6x3 prop. A 5" is the smallest you can use. A 5x3 is a good prop for pretty fast flying and some loops and such. (I'm speaking as a control line flyer). A 5x4 is good for bust-ass speed, but awful for any kind of loop or stunt. The loops will be too wide. A 5.25x4 is a good combo of those two and will allow better loops and good speed. My favorite prop, at the moment, is a 5.5x3, usually cut down from a Cox or a Master Aircrew 6x3. I have bought some 2" pitch 5.5s to help slow it down and add climbing torque for pattern stunting, but haven't tried them yet. A 2p is like running your car in first gear, climbs hills like crazy. You can compare increasing pitch to shifting gears in a car. At Tee Dee RPM you must balance them well.

For free flight we use APC 5.7x3.

Thanks guys! I'm going to have to modify whatever fuel I can find, probably something the car guys use, with a bunch of castor added in.

Fuel guide link.

http://coxengines.ca/files/FG.pdf

I like 25% nitro/ 20%oil and have a bunch of Tornado 5/3 white nylon props. 5/3 Cox props are decent also. I know all about old props and have that all under control. Never had one come apart in flight yet. I dislike most APC props and will never use them on 1/2A engine.

I bought some APCs because it was all I could find with the 2 and 2.5 pitch I wanted to try for aerobatics. They're for free flight. The holes are too big. I know how to work around it, but I was surprised a 5.5x2 would have a large screw hole. I wish Top-Flite still made nylon 1/2A props.