Sizzler, Estes kit #1906

After a cut has been made on a tube, a pressure ridge from the point of the knife will show up on the lip of the inside diameter of the tube. Use the smooth part of a hobby knife handle to knock it down and smooth out the I.D. of the tube. A thumb nail will do the same thing. I belive it's called burnishing.

Why bother?

Because you want things like nose cones and centering rings to fit the inside diameter of the tube. Not the diameter of the pressure ridge.

Now the material from the pressure ridge has been pushed up onto the lip of the tube.

Take a q-tip dipped in thin CA and soak it into both ends of the tube. Do the same to the edges of the slots also.

Yup ,soaking the ends and edges does make a big difference ,as well as the MMT tube ends.I always soak the nosecone end really well (saturated) as with the aft end.What would you do without superthin CA

I soaked the cardstock nosecone hat for my TLP Harpoon with superthin CA.It made it very hard and stiff.I then filled it with 5 min. epoxy and plunked it down onto the nose cone.......rock solid and the CA sands like a dream !

Paul

sodmeister said:

Yup ,soaking the ends and edges does make a big difference ,as well as the MMT tube ends.I always soak the nosecone end really well (saturated) as with the aft end.What would you do without superthin CA

I soaked the cardstock nosecone hat for my TLP Harpoon with superthin CA.It made it very hard and stiff.I then filled it with 5 min. epoxy and plunked it down onto the nose cone.......rock solid and the CA sands like a dream !

Paul

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More good tips. Thanks Paul.

I don't know what I'd do without thin CA.
But I do know what I'm going to do with it!

Now that the material from the pressure ridge has been pushed up onto the lip and hardend with thin CA, use a sanding block to sand it off and make the lip flat.

Make a tool like the one pictured. Sand the I.D. of the tube until the CA is smooth. When really smooth, CA seems nearly frictionless. The tool can be used for adjusting centering rings also. Use scrap BT and a dowel. Attatch desired sand paper with spray adhesive, like 3m or Duro. Duro spray adhesive is available at Wal Mart and Lowes.

I'm waiting for some finishing epoxy to show up. I want to see how it makes a balsa nose cone look.

Adrian Monk's (CIT Graduate, CC Professor) work bench.

Gotta start the motor mount somewhere, so I'll start here.
Pre fillet photo op.

Post fillet photo op.
Those are some good un's, eh?

Now I have to wait a long time for it to cure. Then I can camence working off this starting point. Then I can tweek the fin tabs and position the rest of the custom guts.

To expand picture without losing all the detail, place curser on photo, right click mouse, select open link, click arrowhead in bottom righthand corner of screen (next to 100%), select 125% or 150%.

The scrap body tube is going to be a baffel.

It gets sliced down the middle.

Stick it into (stick it? ) the body tube and lay down a line where the edges overlap.

Cut it.

(I really used sissors)

Test fit.

Measure baffel for inside diameter and make some bulkheads.

Place a line across the center of the bulkhead. Draw a second line 5 mm from the center line.
This lets the baffel plates overlap, forceing the ejection gas to change directions (this is where the burning particulate gets droped out of the flow), leaving no chance of the gas just blowing right up the center.

That's my story,
and I'm stick'n to it.

Trim and adjust until you get a custom fit.
Glue together.

Here's how the baffle works.

The pressure wave from the ejection charge has to move up the motor tube because the motor hardware is mechanicly secured into place, blocking one of the two exits. The path of least resistance is up the motor tube, through the baffle, into the parachute compartment, pushing out the parachute and nose cone to reach the only exit available to the pressure wave.

Unless there's a CATO and a new exit is created.

The path the pressure wave has to take is already full of cool air. As the pressure wave travels up the motor tube it's forcing the cool air up the motor tube, through the baffle and pushing out the parachute. The parachute is deployed by cool air and will be long gone before any hot gas from the ejection charge reaches the parachute compartment. Pretty cool!

bradycros said:

Make a tool like the one pictured. Sand the I.D. of the tube until the CA is smooth. When really smooth, CA seems nearly frictionless. The tool can be used for adjusting centering rings also. Use scrap BT and a dowel. Attatch desired sand paper with spray adhesive, like 3m or Duro. Duro spray adhesive is available at Wal Mart and Lowes.

Click to expand...

I have a similar tool in my arsenal that I'd completely forgotten about until I saw your picture. Thanks for the reminder.

I dug it out last night and used it to smooth the CA on the insides of one of my tuber's fins. Much faster than hand sanding and great results.

In typical OCD fashion, I have three sanding tools. One coarse, one medium, and one fine.

What's OCD?

I like the pic of the rockets on the bench. Nice looking group.

You mention finishing epoxy to smooth the balsa nosecone. I'm not sure the specifics of what you will be using, but in my experience, straight epoxy is too much of a pain to sand. I have a few different fillers and I don't remember which ones make it easier to sand, but I know which pail to get each from. . .

I also seem to have better luck wet sanding than dry sanding, but only if the components can get wet.

I really haven't found the 100% ideal solution yet, so take anything from the above with a grain of rock salt.

Keep the pics coming. You've just got to love the 1906.

Sandy.

bradycros said:

What's OCD?

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Obsessive Compulsive Disorder. It's what Adrian Monk suffers from.

o1d_dude said:

Obsessive Compulsive Disorder. It's what Adrian Monk suffers from.

Click to expand...

Ah...

Baffel completed.

I nearly fell into the bog of stench. :eyepop:

I forgot to install a path thru the baffel for the shock cord.
Glad that was noticed before the assembly was glued into place.
Holes were drilled thru the top & mid baffel plate, then the bottom centering ring.

The holes are filled in with a very hard black tube.

The very hard black tube is filled with a very strong shock cord.

This Sizzler has gotten a few upgrades so far.

bradycros said:

You have an eye for detail. :cyclops:


The long answer is:

They are .7625 mm to thick, because
the original fin stock was 3/32nds of an inch
3/32nds of an inch = .0937 inches

The Scaling Factor (S/F) is = 1.677254
.0937 inches multiplied by the S/F = .1571586
.1571586 multiplied by 25.4 mm (1 inch) = 3.9918284 mm (or 4 mm)

5/32nds of an inch works out to 4 mm
11/64ths of an inch works out to 4.4 mm
I don't have those thicknesses available to me.

I do have 3/16ths of an inch available.
3/16ths of an inch = .1875 inches
.1875 inches multiplied by 25.4 mm (1 inch) = 4.7625 mm

That's less then 1 mm over scale, I can live with that.

After bevels are made on the fins, the extra thickness should be nearly undetectable.
Anyways, dat der's wot i is thunking.

Click to expand...

I wish I had been following this thread more closely. Scaling fin thickness sort of bit me on the butt. When I built my 4" Photon Probe, I scaled the fins. As it was my first major upscale, I didn't realize how much that all that thick fin area would contribute to the weight of the rocket. Mine ended up weighing in at 5.5 lbs.

You are using basswood where I used doubled aircraft ply. Still, I wished I had used thinner wood.

judo said:

I wish I had been following this thread more closely. Scaling fin thickness sort of bit me on the butt. When I built my 4" Photon Probe, I scaled the fins. As it was my first major upscale, I didn't realize how much that all that thick fin area would contribute to the weight of the rocket. Mine ended up weighing in at 5.5 lbs.

You are using basswood where I used doubled aircraft ply. Still, I wished I had used thinner wood.

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While all the upgrades do add weight, scaled fin thickness being one of them, it's fine with me. I am not at all concerned with getting maxiamum altitude out of this rocket.
To me, performance means did every phase of lift off and recovery happen as planned? Did I get the rocket back in one piece so I can launch again? That's performance.
I don't have RocSim to get an estimated weight, but if a D12 doesn't do the trick, one of the 24 mm RMS reloads will.

Sandy H. said:

You mention finishing epoxy to smooth the balsa nosecone. I'm not sure the specifics of what you will be using, but in my experience, straight epoxy is too much of a pain to sand.

Keep the pics coming. You've just got to love the 1906.

Sandy.

Click to expand...

There's a fella who posts here (TRF) called sodmeister. He told me the 20 minute finishing epoxy works well on balsa nose cones. He seems to know a thing or two about constructing rockets.
After you look at some of his work, you may agree that he does indeed seem to know what he's doing.

www.rocketryforum.com/showthread.php?t=17117

www.rocketryforum.com/showthread.php?t=16057

www.rocketryforum.com/showthread.php?t=16159

www.rocketryforum.com/showthread.php?t=16006

www.rocketryforum.com/showthread.php?t=16047

To expand picture without losing all the detail, place curser on photo, right click mouse, select open link, click arrowhead in bottom righthand corner of screen (next to 100%), select 125% or 150%.

Thanks chum for the kind words ,but I get lucky once in awhile I just wish i had more time on my hands.I`ve learned a few things on this site ,and there are ,in all honesty ,some pretty talented people here that make my stuff look like.....................stuff

You`ll find the 20min finishing epoxy pretty easy to sand....AND ....it works great to stiffen paper/cardstock shrouds and the like.

Cheers

Paul (who must locate a TLP FLAIL and Martel.....who has one ?)