First Level 2 scratch build, upscale Estes Shadow

o1d_dude · Oct 4, 2012

qquake2k said:
What have I gotten myself into this time??? Boy that 38mm motor tube sure looks wimpy.

The size differential sort of puts the whole 38 vs 54mm motor tube in perspective, doesn't it?

Not too late to make the switch to a 54mm tube and a motor adapter if needed.

54mm motor reloads are cheap. Less than a tank of gas for my 32 gallon Bronco fuel tank. LOL!

qquake2k · Oct 4, 2012

dixontj93060 said:
Yep, needs to be 54mm for that size rocket.

You know, I've thought long and hard about 38mm vs. 54mm. I've decided to stick with 38mm for several reasons. A 38mm J350 reload is $58. A 54mm J250 is $73. I already have the 38mm hardware. If I went to 54mm, I'd have to buy a $116 motor case. I know I could adapt down, but then I'd worry about the volume that the ejection charge has to pressurize. With 38mm, I can go up to a J510, which will take it to over 3000ft. That's more than enough for me.

qquake2k · Oct 4, 2012

o1d_dude said:
The size differential sort of puts the whole 38 vs 54mm motor tube in perspective, doesn't it?

Not too late to make the switch to a 54mm tube and a motor adapter if needed.

54mm motor reloads are cheap. Less than a tank of gas for my 32 gallon Bronco fuel tank. LOL!

Yeah, but 38mm reloads are less than a tank of gas for your Taurus!

qquake2k · Oct 4, 2012

GrossApproximator said:
No kidding; the 38mm does look small. And I think the 29mm motors are big! I can't imagine what these things sound like at the launch field.

Big motors sound awesome! Especially sparkies!

chadrog · Oct 4, 2012

You could fit 5 38's in that pipe.

bill2654 · Oct 4, 2012

Jim, Why not go ahead and install a 54 motor mount now and use the adapter? Then if you wanted to sell the rocket some day it's already set up for 54mm. Everything that I build now gets a 54mm motor and I just adapt to 38mm. Just my 2c.

qquake2k · Oct 4, 2012

bill2654 said:
Jim, Why not go ahead and install a 54 motor mount now and use the adapter? Then if you wanted to sell the rocket some day it's already set up for 54mm. Everything that I build now gets a 54mm motor and I just adapt to 38mm. Just my 2c.

I worry about the volume of a long 54mm motor mount tube. The BP well is smaller on the 38mm forward closure. I don't have a source for BP, anyway.

qquake2k · Oct 4, 2012

Well, I decided to weigh the components today, and I'm glad I did. Open Rocket was way off. Instead of a little under 9lbs without motor, now it's 11lbs. By changing the fins to 1/4" and going with slightly smaller hardware, I was able to get it down to a little under 10lbs. Looks like I'll need a bigger parachute than I thought, too.

bill2654 · Oct 5, 2012

Get the 5' surplus chute from Aerocon. Only $12.

qquake2k · Oct 5, 2012

bill2654 said:
Get the 5' surplus chute from Aerocon. Only $12.

I looked at that, actually, but I need a bigger one. I looked at Aerocon's 72in chute, but it's too heavy. I found a new Top Flight 70in chute on Ebay for $36 shipped. It should be here next week.

qquake2k · Oct 5, 2012

Finally got the bandsaw bearings replaced. There must have been grease on the new ones, because the first cuts I made were very dirty. I cleaned the bearings and blade with brake cleaner, and it's a lot better. Whatever is still there should wear off.

qquake2k · Oct 5, 2012

I finally got the centering rings sized on the lathe. Took a while, I'm not used to working with such large rings. The center holes were cut with a 1-9/16" hole saw, and sized with the Dremel. Got one done before the Dremel battery died. That li-ion battery lasts so long, I never think about charging it.

qquake2k · Oct 5, 2012

That coupler is huge! I'm so paranoid about the volume, I made a third centering ring that will go on the forward section of motor tube, and inside the coupler. Should take up almost half the space in it. I wonder how much CA the coupler's going to need to flood half of it...

qquake2k · Oct 5, 2012

Using a guide I had created and printed on card stock, I marked the locations of the vent holes in the baffle, and the holes for the u-bolt. The u-bolt holes were drilled with a 21/64" bit. I drilled 1/8" pilot holes for the vent holes. Using a 1/2" forstner bit, I drilled the vent holes from both sides to keep them clean.

qquake2k · Oct 5, 2012

I wanted backing plates with a bigger footprint for the u-bolts, than the ones they came with. I made my own from 1/8" x 1-1/4" aluminum bar. I like mine much better.

qquake2k · Oct 5, 2012

I'm very happy with how the baffle turned out. The bulkhead turned out pretty good, too. I decided to use some smaller u-bolts I found than the first huge ones I bought. I drilled new holes in the bulkhead for the smaller u-bolts, which have a shorter span. They're 5/16" diameter like the bigger ones, just shorter and narrower.

qquake2k · Oct 5, 2012

I filled the extra holes in the bulkhead and baffle with epoxy. Some aspects of rocket building are just so exciting! :tongue:

iter · Oct 5, 2012

Thank you for sharing the photos. Your woodworking is quite inspiring.

I notice a desire to go and build a fat rocket myself. Must... finish... glider... first...

Ari.

qquake2k · Oct 6, 2012

iter said:
Thank you for sharing the photos. Your woodworking is quite inspiring.

I notice a desire to go and build a fat rocket myself. Must... finish... glider... first...

Ari.

Thanks for the compliment, Ari! I must say, your Vulcan glider is amazing. Can't wait to see it fly at Snow Ranch!

qquake2k · Oct 6, 2012

In a total reversal for me, I've decided to build the Shadow XXL lighter rather than heavier. So I'm using 1/4" plywood for the fins, instead of 3/8". As usual, I pinned the fin blanks with 1/4" dowels before cutting them out on the bandsaw. I used the rip fence to cut the tabs this time, so hopefully they'll be straighter than I've done in the past. Match sanding was done on the stationary belt sander, with the fins still pinned together.

qquake2k · Oct 6, 2012

Got the canard fins cut out and sanded.

qquake2k · Oct 6, 2012

I normally use finwraps to mark body tubes for fins. But the circumference of the 5.54" tube is too big for Payload Bay's finwrap tool. So I made my own. I printed out a different type of fin guide to double check, and apparently my calculations were correct. I also got the blocks epoxied to the centering rings that the rail buttons will screw into.

qquake2k · Oct 6, 2012

Holy moly, 1515 rail buttons are big! Sometimes I can be so naive...

qquake2k · Oct 6, 2012

More boring but necessary stuff. Got the tee-nuts pressed into the aft centering ring and epoxied. I usually use 6-32 tee-nuts, but I decided this big boy deserved 8-32. Also sanded the rail button blocks flush.

qquake2k · Oct 7, 2012

I used the bandsaw to cut 4" off one of the body tubes. It actually did better than I expected. I'll flood the very end with CA so I can sand it smooth.

qquake2k · Oct 7, 2012

I made a jig to epoxy the forward centering ring 6" from the end of the motor tube. The jig positions the ring and keeps it level.

qquake2k · Oct 8, 2012

More boring stuff. After sanding the cut end of the body tube, it was smooth enough so that I didn't need to flood it with CA. And using a piece of aluminum angle, I got the fin slots cut. That LOC tubing is some thick stuff!

qquake2k · Oct 8, 2012

I couldn't resist a dry fit of the fins. I cut a half inch piece off the coupler, to use for strengthening the bottom end of the rocket. I also cut the forward motor tube to length and epoxied the motor mount into the body tube.

qquake2k · Oct 8, 2012

I wasn't sure if my fin alignment guide would fit the 5.5" tubing, but it seemed to work fine. I ended up with a gap at the aft end of one of the fins. I put a piece of tape on the back, and filled the gap with epoxy.

chadrog · Oct 8, 2012

Won't be long before you need a bigger stove...

First Level 2 scratch build, upscale Estes Shadow

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