Mo'Best Tank Height, its decision time

Probably a question best answered by Larry but I'm open to all advice. I now have the fusalage, tailplane and elevators glassed and ready to assemble but I noticed that the latest version of Mo'Best has the possibility of raising the tank up a further 1/8" by knotching the top engine bearer compared with the earlier PAMPA Plans Service version that I have built the fusalage from. I have a small window of opportunity to machine back the top engine bearer to allow the tank to lift the extra bit before I glue in the tail and it would be a lot harder to do once that part of the assembly is completed. SO should I do it or should I leave it?

Regards

Mike

I have learned the hard way that, if I do not include enough (excess) capability in an adjustible feature, I will need a bit more range than I have. I'd say to do it, as long as you don't weaken the nose or totally destroy the work you've already completed.

LAST EDITED ON Nov-14-04 AT 11:11 AM (CST)
 
Mike,

I based that mod on my own experience with Mo'Bests running OS .40 FPS engines and 4 ounce metal tanks. A couple of them needed that fuel tank slightly more than 1/8" above engine center line, and I ended up cutting a relief in the engine mount (with a Dremel cutoff wheel, in case you ever have to do it) AFTER the ship was finished.

Subsequently, I just cut the relief when I built the ship. In most cases it probably won't be needed, but if not, it simply has a 1/8" Lite Ply shim in there. No weight penalty or anything.

There have been several discussions about tank height and fuel head, as well as the merits (or lack) of recessing the tank. I've been told that the conventional setup (non recessed) works perfectly well for profile ships. My assertions are based only on MY experience, wherein I started getting very good profile engine runs after I recessed the fuel tank (as per Bill Melton's suggestion), so I continue do it that way.

I've accepted that people feel differently about it, and the Mo'Best kit (I'm still working on) has provisions to plug the tank recess cutout if desired.

Good luck!

[photo not recovered: 3e69bb3870f12ad5.jpg]

Q. Why do we find things the LAST place we look?
A. Because NO ONE is stupid enough to continue looking AFTER they find something..

LAST EDITED ON Nov-14-04 AT 11:32 AM (CST)
 
Thanks guys I'm off to the workshop Dremel in hand Pics later
EDIT: its now later by 10 mins here is the picture.

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I used a 1/4" router bit and cut back to a pencil line. Now safely completed and just need to restore the epoxy coat

Regards

Mike

A little late, but if you were to be using a plastic R~C tank setup with a fixed uniflow, you don't need to move the tank, just rotate the uniflow tube to raise or lower the end of the tube inside the tank. I had the idea of soldering a hex nut onto the tube just forward of the rubber plug, to allow tweeking with an open-end ignition wrench, without removing the tank. Still seems like a good idea. Steve