ACR PSR 1824 Build Thread

Not too many of these out there and I found one on sale for the right price from a vendor at a club launch. Pictures to follow but it's going to be a very busy week followed by a vacation. I WILL be taking the rocket with me. It is, after all, MY vacation.

Pictures to follow. Sorry. Stay back you vermin! (Whipcrack! Whipcrack!)

This one takes quite a bit of patience to build and get everything fitting and sliding right, but it is worth it in the end when those boosters come off and form a Korolev cross. A8-3's in the boosters make it low enough to see the separation well. If I were to build again I would strengthen the body tube a bit above the core 24mm mount. After several ejections and landings the minimum diameter tube can weaken at that spot. The ARC PSR 18/24 needs a good clip whip. Staging it and using B6's in the boosters would be real manly. Keep plenty of eyes on it because pieces will be raining down. Have Fun!

Daddyisabar said:

If I were to build again I would strengthen the body tube a bit above the core 24mm mount. After several ejections and landings the minimum diameter tube can weaken at that spot. The ARC PSR 18/24 needs a good clip whip.

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1. Sounds like a good place to sleeve a scrap piece of tubing.
2. Clip whip included! See pictures below.

Those left over yellow Estes tube spacers work well too.

Daddyisabar said:

Those left over yellow Estes tube spacers work well too.

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<The Brain voice>

YES!

Ok, ok. Starting off with the bag. No, I didn't pay that much for it.

This guy is serious. Below the fold are the instructions that you must build exactly as instructed. If you "don't do instructions, YOU DO THIS TIME!" At least the kit comes with a clip whip for a 5-motor cluster.

That might have been the old retail price. They go from $25 to $50 (with out clip whip) when they are on Ebay. There is quite a bit to this kit and I felt like it was quite a bargain when I paid $28 for mine a few years back on Ebay. You just have to hit a slow auction and if you have the patience to do that then you have the patience to build this kit. Harder to build than a Semroc Hydra 7. It is the hardest 4FNC kit I have built. Listed as Skill Level 4 it is every bit of that and even more towards a 4.5 when you try to paint it.

Parts all out.

judo said:

This guy is serious. Below the fold are the instructions that you must build exactly as instructed. If you "don't do instructions, YOU DO THIS TIME!" At least the kit comes with a clip whip for a 5-motor cluster.

Click to expand...

This kit is not for those who do not read instructions. You read the instructions over and over again, you read them after every step, you go back and review them after the build.

The first step is to mark the 5 body tubes. After that, sand off the glassine for a better glue bite and remark the lines. I used a flexible file for that task.

Next you need to cut the "interlock rails" from provided stock. For this I used a "Lumberjack Cutter" for Pitsco Education. I purchased it for another project but it serves me well here. The rails are cut to 1-3/4 inches. I used a stack of sticky notes as a block and let the single-edged razor blade cutter to the work. It made for nice, square even cuts. with just the lightest touch for cleanup.

The interlock rails get glued to the base of the booster tubes EXACTLY on the lines and you must leave no fillets. I used Trim and Mold glue applied with a tooth pick. As a reality check I mated the booster tubes together with a dummy engine just to check the alignment. I impressed myself with the precision I achieved. I'm rarely if ever that correct.

Now for the "interlock tabs." I chopped these from the balsa stock. I then deviated ever so slightly. (GASP!) The instructions call for a cut length of 9/16" with a line drawn at 1/16" drawn from one end. Sand off back to the line resulting in a roughly 27 degree bevel. I used another Pitsco tool to achieve the same thing. The bevel's purpose is to mate evenly with the adjacent booster tube. They will actually not be used until a few more steps.

That's going to be it for about a week. Things to do, x-rays to take.

Ahhh, a clean work area, proper tools and techniques, A good build thread that all can emulate. I think I had a Cosmodrome Vostok and a few scratch builds going on at the same time on my messy table:y:

I'm enjoying the thread. Mostly I'll be lurking, but count me among the interested!

op:

judo said:

The instructions call for a cut length of 9/16" with a line drawn at 1/16" drawn from one end. Sand off back to the line resulting in a roughly 27 degree bevel. I used another Pitsco tool to achieve the same thing. The bevel's purpose is to mate evenly with the adjacent booster tube.

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I am currently working on my beveling skills. I'm interested in the use of this Pitsco tool you mention. If you would care to elaborate, I'd be very interested!

[I now return to lurker mode]

Marc_G said:

I am currently working on my beveling skills. I'm interested in the use of this Pitsco tool you mention. If you would care to elaborate, I'd be very interested!

[I now return to lurker mode]

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Here's the link for the tool.

I think it is primarily intended to aid in building their scale architectural buildings and bridges.

Interesting. Thanks.

Back from vacation. Not much building done. All of the interlock tabs are beveled. I'm at the align all the tubes together perfectly step. PITA!

judo said:

Back from vacation. Not much building done. All of the interlock tabs are beveled. I'm at the align all the tubes together perfectly step. PITA!

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They don't have to be perfect before you paint it. Finishing and Paint will change everything so you have to do it all over again after paint.

Daddyisabar said:

They don't have to be perfect before you paint it. Finishing and Paint will change everything so you have to do it all over again after paint.

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"Help me! Help me!" - Sheriff Bart

Oh, and this is my real work bench. Explains the kitchen table, huh?

All I gone done on the rocket was completing the of the bevels, cutting electrical tape to simulate paint, and cutting the spacers for the alignment of beveled interlock tabs. The first picture below actually goes in the last slot.

As the pictures show, I finally got my booster tubes aligned to where I found them to be acceptable. Starting at the bottom and rotating counter-clockwise, I used TBM&T glue sparingly to mount the first set of interlocks, allowing about 2 minutes for drying time. NO FILLETS YET! Next came the upper interlocks glued on in the same manner. I show all four boosters separated to show how they are set up. Next I need to give a light sanding to the contacting surfaces but that will not be shown.

Question for Daddyisabar: After the sanding, the instructions call for tapering the top of the interlock rails. What exactly did you do on that step? The instruction photos are not very helpful.

On the last picture you need sand the top of the interlock rails at approx a 45 degree angle with the long edge of the rail facing the outside of the rocket and the short edge facing the inside of the booster. This makes siding the booster set on to the main body easier down the road.

Sounds like I need to reassemble the stack to better visualize that one. Err.

You just need to knock the inside square edges down so they do not catch on the bottom end of the 24mm body tube when you are sliding the boosters on to the sustainer.

The next step calls for CA hardening and beveling of fins. I'm thinking of just rounding leading, tip, and trailing edges. I can go faster that way. I'm going to review some thoughts on papering fins. I have plenty of blank shipping labels.

I won't be able to post any pictures. On Friday, May 16th as I was doing a bit of gaming, the lights dimmed in my computer room and my computer went black. I've been suffering random power failures in my neighborhood so I though nothing about it. But as I looked around the room, everything else had power. I have a window on the side of my tower and there was no indication of power anywhere. Good thing there is a 5 year warranty on it. It lasted only one-and-a-half. The replacement should be here on the 22nd. I'm having serious withdrawls.