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Eric,

Thanks for your reply and I really appreciate this question. The short answer is not necessary but please note the goal here is efficiency - big rocket flies high on smallish motor.

In...

Kevin,

Good observation regarding the strength of Sonotube. Pulling the HDPE strip and u-channel will shear the angle stock / tube joint. Going to be a tug-o-war for sure. I'll try to strain...

TRF,

May I share my split / collapsible mandrel concept for your comment?

Referring to the picture below:

1. Mandrel is cut lengthwise to 1/4-inch slot
2. Angle stock (black) is glued to...

TRF,

Thanks for your encouragement and excellent advice. I'll definitely follow Troj on the next Sonotube.

Otherwise the topcoat is sanded coarse to 60 grit. That required about 75 minutes. ...

TRF,

Applied mandrel's top coat of fairing compound. That is 20 ounces of epoxy mixed with phenolic micro-beads to peanut butter consistency. Application required about 40 minutes using the pour...

Neil,

Nothing motivates without goals. I will say Red Glare 14 with an 80% probability of making schedule. Much of that comes down to the nosecone, an entirely new skill for me.

Either way,...

Todd,

Also good to know that you are still with The Forum.

Sanded the mandrel near fair using 60 grit paper on a palm sander. Dust was controlled using a shop vacuum. This process required...

CarVac,

Thank you for your reply. I wrestled with that decision. Bottom line? The heavy stuff was available for cheap in 63 inch width. I wanted something wider than the 50 inch cloth used for...

TRF,

One layer of 16 ounce tooling cloth is applied to the mandrel. That will stiffen the Sonotube, will reinforce circularity and will serve as a release surface foundation.

Notes on this...

TRF,

I've finished some other business. Now back to this?

Please find recent photos of the next tube winding station. Features include:

Frame - Made from familiar 1010 extrusion. Outside...

Mr. Salge,

Certainly you are welcome here. The place to discuss propellant formula, however, is in the research section of this forum. If you are aged 18 years, are a US citizen and maintain...

Mr Salge,

May I suggest you join the research forum?

Feckless Counsel

TRF,

Another issue is locking the free ends of a split mandrel. There I'm concerned my mandrel is more flexible and sloppy than Mr. Coker's.

I'm considering a sliding dovetail that runs along...

TRF,

So I'm settled on an all composite airframe. I recognize the expediency of simply laminating Sonotube. But that's another project because:

1. Consistent with the original goal, I'm...

Cavecentral,

Does that lathe use a flat belt, v-belt or toothed belt? Mine is a flat belt and, if I stall the spindle, will slip under the motor pulley. Tight v-belts or toothed belts may not be...

Kevin,

Is your lathe belt driven or direct drive by gears off the motor?

Feckless

Uncrichie,

Smoking the belt we hope?

Feckless

Kevin,

Thanks for sharing and I understand your purchase.

I spent many months contemplating a lathe: Harbor Freight, Grizzly, JET, MicroMark, Taige and Craigslist. Finally I purchased a...

JSitz,

From what I understand Mr. Coker ordered a custom, externally smooth and thick walled tube manufactured by Yazoo Mills, Pennsylvania. So, perhaps, he was spared the surface preparation.
...

Gentlemen,

With humility and all do respect I would invite us to remember our sense of community and responsibility towards every member, especially junior members. Are we bettered as respectful,...

TRF,

Deb included a hand made note on my renewal. Very nice and gave me the very best feeling of community. Surely, geodehunter, you've joined the best of rocketry associations. Congratulations...

Slickwilly,

First, may I congratulate you on design. It looks great and I hope you'll share some flight pictures / data with the forum.

May I ask about your gas baffle? It's hard to tell from...

JSitz,

Thanks for your message and good to hear from you again.

Yes, the tube is rough on the outside: dents, scrapes and spiral grooves. Fairing those will add weight and require labor. So,...

Tim,

I bought the tube as mandrel material for an all composite airframe but, having weighed the tube, am tempted you just glass it and go. Have to balance that convenience against my low weight...

TRF,

Made the trip to my local concrete supply store and purchased a 12-foot length of 20-inch Sonotube. What I learned is:

1. Sonotube is shipped "nested." There is a true 20-inch ID piece...

Eric,

Thanks and I appreciate your generous support. PM is on the net. Is it acceptable to have your decal displayed on the project? That is a lady for sure!

Feckless

Blackbrandt,

You asked about budget so I've attached a scratch sheet total for this project. Rockets fail and, at this scale, you must consider sponsorship, team efforts or a sugar-mama. ...

TRF,

Thanks to you, everyone, for your contributions to this project. Your enthusiasm buoys my own.

May I focus on the issue of wrinkles from a vacuum bagged cylindrical mandrel? Do any of us...

neond7,

Glad to know I'm not the only guy suffering epoxy on glass. Look great and God speed in your flight.

Feckless

Disaster_Guy,

I've cut a lot of fiberglass tube using a power miter saw and a "toothless" diamond blade. Blade cost is $25. Perfect cuts every time. Just drop slow. If you don't own the saw...