MAC MPR 38

1. MAC kits have a reputation for being more expensive than most. That's undeserved. A stock MPR38 is $100, $130 for dual deploy. A comparable LOC Deployer is $120, and a fiberglass kit would be significantly more. Plus the MPR38 comes with significantly more than most kits: Included in that $130 was a 3D printed sled, plus every nut, bolt and washer necessary for the av bay.I spent less building this kit than expected.
2. The reputation for quality fit of MAC components is justified. Goes together like a standard HPR kit, only better. Wing nuts and nyloc nuts for the avbay, stepped thrust plates, beveled fins, etc. Many nice touches.
   
3. Canvas requires more sanding than expected. It's best to sand these parts before assembly, especially the body tubes which have a pronounced grain that wraps around the body. Some aggressive sanding up and down the tube with a sponge is highly recommended. At least canvas is waterproof so you can regularly unclog your sponge with a spray bottle.
4. Related: Due to the grain, you'll use more primer than expected. Mike recommends high-build, which I used, and then after sanding I used some low build to fill pinholes.
5. The DD MPR38 is limited to a big I. I flew a DMS I500 for the first flight. The fin can/booster is relatively short, limiting you to about a 12" long motor. Even if you could get a bigger motor to fit, the fins are relatively small and it will be out of CG. Combine that with the stout airframe, and if it fits, it ships.
   
6. On the other end, the upper bay is spacious. I used 1" webbing and a standard-mil flat chute and everything fit just fine. Top Flight 36" and a streamer drogue fit the airframe and budget

Jozef said:

I have built and flown a half dozen MAC Performance kits and totally agree with your points.... maybe differing a bit on finishing. The airframes doe have a slight texture. I have found that block sanding with a good quality 120 grit dry knocks that down quickly with a 220 grit follow up then primer. I use 2K automotive primer, but have had similar good results with Duplicolor high build primer in a rattle can. To get a similar finish with a cardboard airframe would take hours of spiral filling and multiple coats of primer with between coat blocking. A fiberglass airframe skips the 120 grit dry blocking, but the remaining finishing process is the same for me. BTW, automotive refinishers and custom painters have long gone way from wet sanding substrates. Though recognizing that some of the the rattle can primer products we use may not respond well to dry sanding.
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Wallace said:

Jozef: What color is that? Do you have a paint code? Looks to be just what I was thinking of for a project I'm working on.

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Banzai88 said:

I did a 320 scuff sand, followed by 2 coats of high build primer, wet sand with 400, 2 coats of high build primer, wet sand with 400....smooth as silk and ready for top coat.

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