MAC Performance Pluto Slam Build w/pics

This'll be relatively quick since it's already built and flown. The only limiting factor will be my attention span. Before starting this I did a search here on TRF and found very little regarding this kit. I also spoke with Mike and asked his permission since I did not follow his instructions and made some changes. Did not want to come across as critical in any way. He was very much in favor, so here we go...Unboxing.

The very first thing I noticed was that pointy tip on the well made nose cone. Being all fiberglass and recovery attachment on this rather heavy part consisted of a canvas phenolic disc (washer) that was intended to be epoxied into the tip seemed insufficient. So I started by cutting it off and replacing it with a piece of 6061 bar stock that I had turned into a removable shouldered replacement.

Being not a machinist worked in my favor. I was told that turning a taper would require either a tapering jig or offsetting the tailstock. Since I didn't know better I simply did this.

And came up with this.

Resulting in this.. Yes: I added just under 100 grams, but seeing that it was gonna require nose weight anyhow..

If you feel like forgoing the build bits you can skip right to first flight which was documented a while back. And, no, no one correctly guessed Pluto (or Vought) SLAM. https://www.rocketryforum.com/threads/l2-cert-flight-w-pics-data-and-video.147280/

Was about this point I decided to completely overbuild. Since this thing is such a crazy/cool/insane concept I want to some day build the intake(s)/paint it with catalyzed urethane,build a stand, polish it up and turn it into a display. Of course it also has to fly for a while first, so it'll fly in primer. Two centering rings with the slotted tube to tail joint unreinforced weren't gonna cut it. So I did this...

Mike's roll pin/kevlar attachment is very nice so I used it as is. I tacked everything with the tube and tail slip fitted to make sure it was as straight as possible , pulled it apart and proceeded to fillet the h&%$ out of it. The swiss cheesing is for weight reduction since all I had on hand was 1/2" plywood...

If you Google it you'll find several variations of air intakes. I'm currently leaning toward this version. I like the squashed look more so than round.

Was originally designed as a nuclear ram jet missile traveling mach 3 @ 1000' agl, lobbing multiple (26?) nukes overhead while traveling fast enough to avoid the blast radius. If the shock wave or nuclear blast didn't get ya, the raw radiation from the exhaust probably would. Nice.

Forgot to explain the drawing further...The rubber "cork" with a hole in it was wrapped with teflon tape (the blue stuff in the pic) and used to hold the eyebolt tube in place/make a cavity for the nc shoulder. All bedded in expoy. With the long eyebolt I can easily swap nose weights. Here's a top view.

Here's a shot of fin attachment/tacking with one of Mikes fin guides. The thrust ring is slip fit in place to insure alignment. Works perfect since it's stepped to fit i.d. o.d.

Fair warning, while this is "canvas phenolic" it can still exhibit brittleness. I had the supplied Fastback retainer temporarily stuck on the mmt. tube to insure correct depth. It was too tight out of the box and was gonna require some light sanding but I hadn't gotten around to that yet. I had the tubes slip fit together with the fin can installed in the boat tail. I absentmindedly picked it up by the body tube and the can fell out landing squarely on the retainer, jamming it all the way on. It was severely stuck yet required removal for JB weld application. After repeated failures in removing it by hand, I grabbed the nearest thing which just so happened to be the 'ol prybar. Bad idea as you can see. In hindsight I think a little heat would have been a better approach. Luckily it really didn't affect anything since the thrustring/retainer/boat tail interface pretty much takes the load. Was an easy fix with a bit of glue so no "biggie". This is not intended to be critical of the material in any way (I love this stuff) ,anything can and will fail with the proper amount of applied stupidity.

Fun to watch. Keep up the good work.

Thank you. I'm currently in the process of showing my ham fistedness so others hopefully don't follow in those footsteps.

One other self induced problem I had was with Mikes fin guide. It's made out of what is probably 3mm mahogany plywood and is somewhat delicate @ the clipped corners. You need to be gentle with it or it will split at the most inopportune moment, like when you have epoxy starting to set up...Leading to a mad scramble hurried repair. There seems to be a direct correlation between mixing epoxy and discovering problems in your set up.

Nice build so far. I have the same kit in my build pile so I am watching what you discover along the way. I have several of the fin guides and the tolerances are tight. I don't see this as a problem as I dry fit and adjust them with a sanding before I get into the epoxy.

What's the tinfoil for?

That's just a piece of foil tape to hold temporarily hold things together...After the fact

And tightness of the guide wasn't a factor. I was using it as an inclined plane to wedge the fin tabs tight to the motor tube. After I broke it, I took the trouble to find my big rubber band....

As far as "problems" with the kit go, I basically discovered none. As far as kits/parts go, it's by far the best I've had. All problems I had were self induced.

After mating the fincan,boat tail, canards and body tube I deftly applied generous Rocketpoxy fillets using my favorite "tool". A 45 degree pvc fitting, keeps your fingers out of the glue and gives a nice working angle at the same time. Only problem I have with Rocketpoxy is bubbles. I do have a home made vacuum jar setup that would not be a problem since there's a fairly long wait between mixing and application, probably gonna have to try it one of these days.

Electronics were stupidly simple. I just took my "modular" sled system with everything all ready to go and using some nylon spacers cut to give a nice snug press fit, bolted it to the supplied 3d printed sled. And since Mike even includes all necessary (aluminum,no less) hardware.... I do use indexing pins to keep it from rotating and align the pull pins for the outstanding LabRat switches. Sled has all Eggtimer stuff, Didn't even need to change the programming on the Quantum or Quark, just hook it up and fly. Doesn't get any easier than that.

Btw: The switches are not all used at the same time. They're located to align with different switchband locations in keeping with the modularity theme. Would be nice to have dedicated stuff for every rocket but until I become independently wealthy....

Did some minor touch up with spot putty. Turned out to be totally unnecessary. I picked up a gallon of Eastwood high build polyester primer since I've never used it before. It's pretty much what I expected, lightly thinned spray-able Bondo. Biggest tip I had on hand was a 2.1 and it was clearly insufficient. I'd say minimum 2.5, this stuff is crazy to work with but very cool. I've read that you can tape a quarter to a panel and bury it to the point of invisibility. After using it I can see that as being entirely possible. Working with what I had I gave it 2 "medium" coats and called it good. Figure I can sand it out and recoat if needed before paint.

I usually make my own chutes, but after all I've heard about Aercon's 60" flare chutes I just had to try one. For $10 (I got a discount for buying 2) it really can't be beat. They won't work unless you have the space and don't mind the weight. Fit perfectly in the big conical nc and I needed the weight anyhow. They claim 14oz w/bag, mine weighs over a pound without. As long as I was ordering I also picked up an 18" $5 flare chute (date stamped 1968) for a drogue. Really can't top that for a grand total of $15 plus minimal shipping. https://aeroconsystems.com/cart/all-parachutes/60-inch-white-parachute/

I am a huge fan of in flight video so I got this camera and mount from Flight Commander Systems. I usually just tape an 808 on but wanted to try an "upgrade". Overall pretty happy with the mount, the camera on the other hand......

I love the look of those surplus chutes coming down.

Bat-mite said:

I love the look of those surplus chutes coming down.

Click to expand...

Strangely enough, they do have a very cool "military" look about 'em

Original Plan was to L2 with it as such...

Cloud ceiling and financial situation combined told me that wouldn't be happening, at least not on that day. I had an J250 re-load, but felt it would be underwhelming with 10 pounds of mass sans motor. After a bit of head scratching and poking around in Wildman's trailer I came up with this. Loaded, it gave me exactly one caliber of static stability, 13.3 pound pad weight and simmed @ 666 fps @ 4800 and change so I went with it. Only problem I ran into is that particular motor calls for a 54mm seal disc which I nor Tim seemed to have. He saved the day by robbing one out of a complete AT motor he had for sale. Thanks again Tim. After all, who doesn't love sparkies right...