Re: Idk how to build.

**944_Jim** Thu Aug 06, 2020 9:05 am

HD,
The product engine (plastic back, tankless) has a trapezoid shaped bolt pattern.
The tanked Bee variants (Babe, Silver, Golden, Black Widow, Texaco) have a rectangular bolt pattern regardless of material the backplate is made from (plastic/metal).
Of the tanked engines, the Babe Bee has a 5 cc tank. All other metal tanked ones are 8cc.
Then there are the Dragonflies with larger plastic tanks (almost coffin-shaped). Usually they are red or black (and I think I've seen white or translucent). I don't know the fuel capacity on those, nor do I know their bolt patterns.
I hope that helps!

rsv1cox Thu Aug 06, 2020 9:59 am

Now I'm confused.

"Product" engines came in two styles, "Horseshoe" and "Postage stamp". Carl Goldberg made a mount for the postage stamp engine and Jason reproduced it awhile ago and mailed out samples to a lot of people here. Looks like Jim drilled his for the horseshoe engine which has a different mounting bolt pattern. I think that the simple solution would be just to redrill the mount for a standard Babe Bee engine. I doubt that extra holes would be a problem for WC.

**944_Jim** Thu Aug 06, 2020 12:51 pm

Yes, Bob,
You are correct. Both tank-less engine styles are product engines. And yes, the mount has been drilled out for the horseshoe backplate.

Unfortunately this mount was trimmed really closely to the horseshoe backplate...and the engine was originally intended to be mounted low on the nose so the external tank would be centered on the tank. This means the mount doesn't have much area for drilling/re-positioning the engine. Ron Cribbs and I are communicating/coordinating. I'll knock out another mount so Ron's Babe Bee sits a bit higher...no big deal since this is light aluminum stock anyway. Besides, making the BB mount will be faster than making/soldering on the external tank tabs.

The effort will be in doping, making landing gear, and the few little items remaining (bellcrank/lead-out guide). I'm feeling a bit of pressure with the other things I have going on at the same time, but it will be done shortly!