Bar-Clamp engine mount - Finished pictures

Wink...I got what you were doing Rusty ... sounds to me Ron thought you might leave the No Go Gage screw in place to fly

MY way of thrust line alignment is a bit more precise IMO

As I do the ARF P-40 I will try to remember to describe and photo the method

I generally give it the old good enough eyeball. Rusty's idea has merit assuming the front of the fuse is square to the bearers and the bearers are square to the centerline of the fuse. The 4 Orientals I have owned have had downthrust in them. Not always a bad thing as some were purposely providing a deg of downthrust in some stunters. Al Rabe had written a article and some of these had been written in Stunt News in regards to providing downthrust and the effect is has on the wing.

I frequently defer to any discrepancy my keen eyeball detects. It looked straight.

I need to think about an earlier post concerning adding a restraint. I hadn't thought of a bolt breaking, but now looking at it, it seems like a no brainer to cable it. I wish now I hadn't put Loctite on the threads, but I might have to remove them if I can't come up with a good solution with it in place.

I saw it here first and blew it off. Then Doc Holiday reminded me of it over at SH, and I had second thoughts.
Rusty

Use a soldering iron on the head of the bolt for a few seconds and it will soften the Loc-Tite

I believe a cable is combat standard for safety.
Phill

Ken Cook wrote:Use a soldering iron on the head of the bolt for a few seconds and it will soften the Loc-Tite

pkrankow wrote:I believe a cable is combat standard for safety.
Phill

Yup and yup. Combat planes have it cabled to the bellcrank, I think. Needless to say, we won't be doing that, but a cable to something substantial on the airframe.

I think it looks good Rusty , I have used this on some RC back when i was trying to learn.. A safety strap would not bee a bad thing, if nothing else just to keep from losing the engine if a mishap was to happen / I think Ron was referring to the small brass ? screws i seen them but figured there there just to keep the bottom of the clamp in place while installing the engine / upper clamp.

IMO
Obviously there is a safety reason to cable restraint for Combat engines...especially the big block .36s (as well a fuel shut of devices)... the combat model is in an environment where the lines can get cut, or the model center punched and destroyed in flight------ and no one wants a 100+MPH plane, or engine, chasing them

Engine restraint, no matter the mount method, is in --stunt flying--- IMO a low risk caution especially for a accomplished builder and pilot

Yes, there are a few combinations of engine and plane that have inherent vibration issues that (MIGHT/COULD) loosen the engine mount hardware--- in flight---- or over time.... A Good builder pilot, always pre flights and has taken steps to eliminate or mitigate these risks

There in NOTHING!!!! IMO -----more problematic, in this environment, between 4ea 4-40 screws dry screwed into blind nuts vs the bar clamp method Rusty is doing.... pretty long history of this mount method (bar clamp) being sound for stunt flying

I know Rusty is being pestered into considering the cable restraint... OK.... his choice, but I think not all that necessary considering his attention to detail and skill level

I mostly did this post because I got guilted in to the very fiddly addition of a pin in my UK sourced engine test holding fixture.... and the two engines I bench ran, were so vibration free.... it was fun....cranking them down to nearly 8 cycle and then back up to screaming 2 stroke....later...... I had a hard time loosening the cap screws* I had tightened them so hard.... I am convinced that even with a vibrator like a Fox 35 and unbalanced prop...the engine stand would hold the running engine firm.... Thus, I am certain the bar clamp engine mount is tough enough as Rusty is using the set it up

*M5 screws in 9mm thick plates that do NOT bend as opposed to my typical 4-40 screws into soft steel blind nuts....clamping forces are way more then needed IMO