Gap staging lower stage protection

John,

I've found that coating the joints / coupler, with CA works very well as a fire retardant.

If you're going 1 to 1 with your engines and don't use too much tape on the joints or make them too tight, the stages will separate quickly enough that singeing them won't be a problem but like most things, you'll have to get the feel for it as you go.

Randy

Well, I have about a 5 inch gap between the motors, so there is plenty of body tube exposed, a bit much to coat it all with CA. Creating a roll of tin foil that can be placed inside the tube, taped down, then replaced when nessicary was pretty easy, so i'm going to try it out on the first flight and see how it works.

I had to replace the motor mount/stuffer tube of my Big Bertha due to burn-through of the stuffer tube wall on ejection.

On the rebuild, I made a stuffer-tube liner from a coke can. Seems to work.

I believe it is the Handbook of Model Rocketry that recommends simple liners made from typing (now printer) paper. Just cut them to size and replace frequently.

Cheap and easy.

Ironically some kids would NOT know what typing paper is without the above lesson!

Baby Big Berthas are cheap. Try it w/o any protection and you may find your worries may be a bit out of proportion.

If you must, coating the id with CA works. Also rolling up a sacrificial liner works.

Have fun...

Andy

get yourself some .002 nomex paper..... make and replace after a few uses.... or use foil lined bt50 for engine mount tubes...from bms

shockie B)

You could use adhesive-backed aluminum duct tape as a liner - it's a bit thicker than aluminum foil.

-dave w

I wonder how many know what CARBON PAPER is?...lol

And on a related note...do Mechanical Engineering classes, these days, even teach the wonders of drawing with a classic drafting set, as we all learned? (I say this as I admire my old Dietzgen set, handed down to me by my Dad, many years ago...)

I'll see your carbon paper and raise you a mimeograph paper...

David Erbas-White

I couldn't say anything about ME, but as a Technical Theatre major we are recquired to learn hand drafting before CAD can be used.

Ben Romashko

Anyone see my Slide Rule?

I traded it in for a abacus :)

Ted Novak TRA#5512 IEAS#75

I've still got both. And know how to use both. Maybe not very well, but...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

I just bought a lot of three off of eBay - a Pickett, a K&E, and an "unknown" brand, all in good working order, with cases. Amazingly, only 2 bids were made, including mine, and I got all 3 for $12.62, including shipping and tax. I'm looking forward to getting them -- a good slide rule is a very useful tool, and these look to be in great condition.

I plan to teach my nephews how to use them. I wish schools still taught slide rule use; using one makes things like keeping track of significant figures and estimating the order of magnitude of results in your head as a double-check automatic, and those are skills that are in very short supply these days.

Too many people take whatever number pops up in their calculator's display as gospel, regardless of how many decimal places it shows, or how far off from reality (due to a mistaken keypress) it obviously is. If they'd just double-check it in their heads for basic "sanity", they'd realize they made a mistake, and go back to fix it.

- Rick "Sorry for ranting on innumeracy; it's a pet peeve" Dickinson

There were "slide rule cults" at Harvey Mudd College when I hosted Rocketcon-84 Tech Convention.

Jerry

Yeah, it's right there next to the inkwell.

No but from my experience, you need to be within 6 feet of the base. ; )

Randy

I'll up the ante by raising you a Letraset and a T-square!