Keeping it Simple first self build

[cavecentral]

Does Estes = Apogee? I technically had an "apogee" airframe.
If I remember correctly Rex did mention something about the airframe not being strong enough a while ago....:eyepop:

Not sure on Apogee, the BT-60 designation made me thing Estes. I'm familiar with Estes and LOC. Huge difference between the wall thickness of two for the 38mm and 54mm motor mount sizes. Strengthening with super thin CA can help some, but I am not a speed guy that pushes the components to their limits.

LOC 38mm - ID = 1.52" OD= 1.63"
BT-60 - ID 1.595" OD=1.637"

Blue Tube 2.0 or fiberglass work nice too. FG can get heavy though.

 

[dford]

BT60 was easier to put a size in perspective I suppose. For some reason I thought I heard somewhere Estes made Apogee body tubes? In my mind I had hoped otherwise. I really think tear dropping into the majority (including ttw tab) being 1\16 thick played into this.

 

[dford]

.11 Loc
.021 actual [mine]
.042 advertised [apogee](same as bt60)

I took a measurement of three tubes all equating to .021 wall thickness. Literally HALF the thickness as advertised (which even as advertised now seems weak) anyone think I should contact Apogee about this?

 

[Rex R]

Apogee lists an inner diameter and an outer diameter of 1.595" & 1.637", (o.d. - I. d)/2 gives me a wall thickness of .0021". which is nominal for thinwall body tubes in that size.
Loc. 38mm motor tube (IIRC) has a wall thickness of .05" and are just a hair smaller than Bt-60 (outside diameter), which means that most plastic nose cones for lpr will not fit. however balsa nosecones can be made to fit...500 mph big bertha anyone .
Rex

 

[dford]

Revisiting a failed attempt I did buy a pack of these body tubes so I have built another mid sized. At this point I have a much better fin jig out of cardboard. I printed a template off payloadbay.com for centering rings and fin alignment. I also now have angle aluminum for ensured straightness.

I am to the forward centering rIng is installed with motor mount into\onto body tube. Fins installed ttw. Without the after centering rIng on I ensured of it. I also have one fillet of tight bond 2 on the body tube to fins. I'll be filleting the ttw tabs tonight.

My thought is what if the body tube truly isn't strong enough for the motor thrust? I am using a more rounded trapezoidal approach to 1\8 inch fins installed correctly but what if I papered the body tube, filled the seems and sanded and so forth?

Shouldn't doing this reinforce the paper in a way like layers of a composite lay up? 45-90-45-90?
It seems the paper wouldn't allow the spiral kraft paper to flex and crumple as well...
Doing a straight 45 degree composite lay up is super weak, paper should work the same way I'd imagine.

Anythoughts?