Need Tech Terms and Suggestions

Apr 18, 2005 32 Replies

I found a local manufacturer of custom filament wound Carbon Fiber, Kevlar & Glass items. Tubing ( From 9.4mm up to 300mm), odd shaped objects etc.... I'm going to get them to make up some 75mm, 54mm & 38mm tubes, Couplers, C-Rings, Nose cones.......Pretty much the entire rocket!



I'm going for a 'High Performance, High Tech' kinda build...........75mm airframe & a 54mm MMT. (Still in Planning) I want the parts to be as 'Thin Walled' as possible but able to withstand Mach 1+, a K-700 54mm motor or similar & high velocity deployments.



Does anyone have any suggestions as to how thick I should get them to make the Tube Walls, Fins, NC and C-Rings/Bulkheads etc? Should some parts of the rocket be constructed of different materials....Carbon or Kevlar?



They're only an hrs drive away which comes in handy. I'll be calling in to see them and so I don't look like to much of a Dunce, what's some Tech terms for the stresses that the parts will have to withstand? I want to walk in and say...." I need this, this & this.........I want it made from this & this. It has to withstand high temps, high ??? stress and high ??? loads..."



Any Ideas??? CJC..


1/32" airframe, 1/16" fins+

Make sure the motor *really* will fit in the tubing....

As in Dia???

Some of their Standard Internal Dia's are 76mm, 57mm, 54mm, 40mm &

38mm....among others. These are 1.3mm Wall Tubes. Custom as required...

When using a PML 75mm, 54mm or 38mm MMT as an example, is there much play / movement of the motors??? Are they tight fits or do the motors slide in easy???

This is a L2 Bird and...well....I'm not even L1 yet and don't have any motors laying around to check......... I only have 29mm motors and know that they slide into PML 29mm tubes nice and slick with a bit of play....Tight fit with LOC 29mm tubes. I can go off their ID's as a rough guide.

You could check the AT dimensioned drawings to get exact numbers, thats more what I was thinking of.

Of course if you go for a tube with the same ID as PML or LOC tubing you should be ok. I was wondering if the ID of PML '54mm' phenolic is actually

54mm, you might want to check. I'm fairly sure that, for example a Pro38 is 38.1mm, depending on tolerances a true 38mm tube might be tight.

As for motors, my PP Pentamax motor (54mm) slides into a length of PML 54mm tubing freely, but once in there is very little play at all. Same goes with my WCH 38mm motor and LOC 38mm tubing.

LOC Motors

1.14 1.125 1.52 1.50 2.15 2.125 3.00 2.98 3.90 3.875

Inches of course!

Jerry

You mean LOC don't make a 3.9ft BT for 3.875ft motors ?!?

;)

They do make an extra thick wall tube ESPECIALLY for 98mm motor mounts.

Be VERY careful what you wish for.

Jerry

Hmmm. They make an about 5.5" and about 7.5" tube :)

How about letting us in on the manufacturer name and location? A website address would be nice too. A group purchase would be much cheaper.

Mike Fisher

Composite Spars & Tube - CST

WTG Pty Ltd PO Box 651 Caringbah NSW 1495

***AUSTRALIA***

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They export tubes to the USA, Asia & Europe aswell..

With the 1/32 AF & 1/16Fins a quick draw shows it comes in about 1/3 less weight than a Phenolic/G10 Glass/Birch build...

Yes, at 10x the cost.

Only helpful IF optimum weight is near minimum weight.

Otherwise it is 100% cool factor.

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Jerry

"Get high. And fast."

By making it weigh less overall or even the aft Fin Can/Motor assy.. it'll allow me to move the CG forward by the same distance with less nose weight.... The fin design....aka LM....doesn't help much with stability...

Optimum weight would be determined for the different motors used.......and for the larger motors the amount of nose weight added (For Optimum and or Stability) will most certainly cancel out any benefits from the reduced rocket weight on a rocket this size..3inch........I was looking at it from a stability point of view.... I build little rockets with little motors at present and every gram forward or aft of the CG counts a fair bit....

The COOL factor is a must have!!!

Nice pics....... Who? What? Where? When? & Why?

Impossible to say on rmr without a lot of "bad noise".

Email.

Use longer motors:

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K660

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6400M

Ignore the whiners behind the keyboards.

Sounds like a scam is a brewing.

you WANT people to ignore you?

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