MAC Performance ETHOS 2.0 Kit Review and Short Build

[Jozef]

I just received the first release of the new MAC Performance Ethos 2.0. It is a longer, lighter and simplified version of the original 4 inch diameter ETHOS designed around 38mm power in a singly deployment configuration. It will fly on larger G motors, but is also a great L1 cert platform should you decide to make the jump one day. A versatile rocket. ETHOS 2.0 is 50.7 inches long and the weight of my kit components totaled 43 ounces. As with all MAC Performance kits, the airframe is durable canvas phenolic as are the 1/8" thick fins which are expertly beveled. No time consuming beveling ply fins and filling of cardboard airframes. The kit includes a printed tailcone that accepts an Aeropoak retainer or any similar slip on retainer. Centering rings are 1/4 birch ply. A U-bolt assembly is included for the fore centering ring. The Pinnacle nosecone comes equipped with an eyebolt for harness attachment. Here are a few photos of the kit contents. Mine has the optional nosecone bay kit and Aeropak retainer. You can refer to the high power forum for further review and a soon to follow short build sequence.

 

[Jozef]

The first step in this build is to dry fit the motor retainer to the motor tube. This is required to establish the position of the forward centering ring and sets the length of the motor tube aft of the airframe to allow for mounting the tailcone. On ETHOS 2.0, the motor retainer is epoxied onto the motor tube AFTER the tailcone is mounted. For the Aerpopak, I marked 3/8 inch from one end of the motor tube and made a guide line with masking tape to trim the tube until the retainer slips on easily



Determine the position of the forward centering ring on the motor tube. The fin side of the forward centering ring should be at the leading edge of the fin slot. Dry fit the aft centering ring and tailcone. Test fit the motor retainer so it is fully seated on the motor tube and fully inset in the recess of the tailcone.



From this point on the epoxy begins to fly. More pics and tips coming soon

 

[Jozef]

Epoxy the forward centering ring to the motor tube at the location determined in the dry fit sequence. Use the epoxy of your choice. I tacked the centering with thin CA to ensure its position before applying epoxy. Of course, the motor tube should be scuff sanded as will any surface the requires epoxy

Attach the U-bolt assembly to the pre drilled holes in the centering ring and attach your preferred harness tether to the U-bolt. (not shown).

Apply epoxy just aft of the fin slots leading edge. Insert the motor tube with dry fit aft centering ring into the airframe. Be sure the U-bolt is not inline with a fin slot. I also inserted the fins and tailcone to ensure fit and alignment. Stand the assembly upright and allow the epoxy to fully cure. I attached two short screws the aft centering ring to aid in fitting and removal.

Epoxy the fins in place. I use Rocketpoxy with the double butter method, applying epoxy to the fins tab root and fin tube leading edge. Slide on a fin alignment jig. I also dry fit the aft centering ring.

I taped off the airframe and fins with strips of blue tape and applied small fillets using rocketpoxy, doing two adjacent fins at a time. There is a lot of available info in the forum regarding fillet methods. Since these are a small radius I just used a latex gloved finger and alcohol to draw the fillet. It is drawn a second time after the tape is removed to obtain a good feather edge

 

[mpitfield]

Looks good Joe, I can't wait to see your paint job. Have you decided on a theme, also are you using electronics, or are you going to keep it a simple pop and drop with just a JLCR?

 

[Jozef]

Looks good Joe, I can't wait to see your paint job. Have you decided on a theme, also are you using electronics, or are you going to keep it a simple pop and drop with just a JLCR?

I am considering using the original ETHOS theme... kind of an orange/goldish pearl from the 2016 Ford Focus. Of course, that can change when I get to the auto paint store and look at chips. The tailcone will be finished in satin black and epoxied in place after the airframe is cleared. JLCR for sure. The rocket is designed around keeping things simple. I did add the nose cone bay kit so a tracker can be added if larger motors are used. Certainly not necessary for a big G or H motors. Finishing work should begin when I get back from a few days of snowmobiling.

 

[wighty44]

...Slide on a fin alignment jig. View attachment 335131

Did you make the fin alignment jig specifically for this rocket?

 

[Jozef]

Did you make the fin alignment jig specifically for this rocket?

I made it about two years ago for a MAC Performance 3FNC kit. It is made from craft foam board

 

[wighty44]

Ok - thanks...

 

[Jozef]

Made a bit more progress on ETHOS 2.0 with sanding to prep for initial primer coat. The 3-D tailcone is printed from PLA plastic so it sands cleanly and doesn't fuzz up. I used 220 grit on a palm sander and rotated it around the tailcone until the print ridges were leveled. Took about a minute. Initial blending of the fillets is with Norton 220 grit. Duplicolor filler primer will be used to spot in around the fins to find any imperfections before an automotive 2K primer is applied. Nosecone prep is next in line...always a lot of "fun" :surprised:

 

[gfunk]

This thing looks awesome! Cool kit, and great job on the build and documentation. If I had to redo my L1, I think it'd be on this kit! If I hadn't just ordered 3 other MAC kits today I'd be checking one out just for fun.

 

[Jozef]

This thing looks awesome! Cool kit, and great job on the build and documentation. If I had to redo my L1, I think it'd be on this kit! If I hadn't just ordered 3 other MAC kits today I'd be checking one out just for fun.

Yup, MAC Performance kits are an easy build and kind of addictive. I understand some really neat stuff is in the pipeline. Congrats on your recent L2.... and thanks for the kind words

 

[EXPjawa]

Yup, MAC Performance kits are an easy build and kind of addictive.

Indeed! I started tentatively with a Scorpion a year and half ago, and am now about to start my 5th MAC build. This Ethos2 is pretty looking, I especially like the tailcone design... Can't wait to see flight pics!

 

[Jozef]

Indeed! I started tentatively with a Scorpion a year and half ago, and am now about to start my 5th MAC build. This Ethos2 is pretty looking, I especially like the tailcone design... Can't wait to see flight pics!

Rick, It may not fly until Mini Midwest Power in early May. Will definitely get a video and some pics. I do plan to have it with me at URRF 5 in June. Ive been behind on builds. Just finished the repaint of my Rayzor that took a core sample at URRF 4. Thanks for helping with the recovery that day

 

[mpitfield]

I especially like the tailcone design

Yeah the design is good, but the guy who designed it is another story

 

[EXPjawa]

Rick, It may not fly until Mini Midwest Power in early May. Will definitely get a video and some pics. I do plan to have it with me at URRF 5 in June. Ive been behind on builds. Just finished the repaint of my Rayzor that took a core sample at URRF 4. Thanks for helping with the recovery that day

Ah, then with luck, I'll see it first hand at URRF. Hopefully the weather will be better this year!

Yeah the design is good, but the guy who designed it is another story

Oh, don't even get me started about that guy!

 

[Jozef]

Yeah the design is good, but the guy who designed it is another story

I second that emotion...

 

[ascastil]

Ok, what is phenolic tubing and what are the fins made out of? Looks like a fiberglass or cf coating on the fins. Do they come like that? Looks like a nice kit.

 

[EXPjawa]

Ok, what is phenolic tubing and what are the fins made out of? Looks like a fiberglass or cf coating on the fins. Do they come like that? Looks like a nice kit.

MAC kits are phenolic-canvas. They use the canvas like fiberglass uses glass cloth, and the phenolic is essentially the resin. The body tube, fins, and now centering rings (some kits, like shown here, still have ply rings) are this material. The motor tube, however, is phenolic over kraft tube. Basically, its lighter than typical fiberglass and a lot stronger than thickwall paper. And its waterproof.

 

[ascastil]

Oh, very nice. Thanks.

 

[Jozef]

Made some progress on paint prep. After sanding the tailcone, I sprayed adhesion promotor followed by high build primer. The primer revealed a few areas to be addressed with Bondo spot glaze putty.

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After sanding the fin fillets, airframe and fins, I sprayed two coats of Duplicolor filler primer to reveal any flaws to be addressed. This is good stuff. Once the flaws are addressed, the primer will be block sanded with 320 grit in preparation for the final 2K auto primer coat. 2K primer cures, it doesn't shrink like single stage rattle can primer. However, it requires good spray equipment, good ventilation and a good respirator. However, excellent finishes can be achieved with your favorite rattle can paint system. Finishing of canvas phenolic is very much like fiberglass and much easier that cardboard/plywood airframes

 

[Jozef]

The Pinnacle nose cone was washed with Dawn detergent to remove mold release then sanded with 220 wet. This helps to minimize the "fuzzies" that are typical when sanding this type of durable plastic. The nosecone was treated with two coats of adhesion promotor followed by two light coats of primer. I use SEM products here which come from auto body supply stores. Any molded nosecone has two seams. Don't try to sand them out or you will make two flat spots the length of the nosecone. I use bond spot and glaze putty to fill the seams. When dry, the seams are block sanded lightly with 220 grit then followed up with 320. It may take a couple of passes to get it right.

 

[Jozef]

Here is ETHOS 2.0 with all component in initial primer. I have a few areas to touch up then it will be ready for final 2K primer and finish paint. Stickershock23 is working on graphics, which will be a variant of those used on the original MAC Performance Ethos.

 

[mpitfield]

Here is ETHOS 2.0 with all component in initial primer. I have a few areas to touch up then it will be ready for final 2K primer and finish paint. Stickershock23 is working on graphics, which will be a variant of those used on the original MAC Performance Ethos.

View attachment 335754

Looking good. You must have a warm shop, painting is not an option for me right now.

 

[Jozef]

Looking good. You must have a warm shop, painting is not an option for me right now.

I do, Mike. The shop is a separate room in the basement. A 325 CFM blower is mounted in the rafters and plumbed inside the wall to the paint booth and vented outside the house through 6 inch dryer duct. The booth itself is nothing more than a large packing carton from U-Haul. The back is cut out to fit over the wall vent that goes to he blower. It sits on a plastic stand and can be simply moved if needed. Inexpensive furnace filters line the back wall of the booth to catch overspray

 

[Jozef]

I ordered the optional nose cone bay kit for this build. It can be used to hold a tracker and / or nose weight if desired for larger motors. The instructions provided with the kit are very good and it has few parts. The first step is to cut the lower section off the Pinnacle nosecone. I wrapped masking tape around the cut line and used a razor saw while rotating the nosecone until the cut is finished.



there are two points of contact on the inside of the nosecone for the bay kit rings. Scuff these areas with 80 grit in prep for epoxy. The wall thickness on plastic nosecones tend to be inconsistent, so you may need to trim thick spots if the stepped ring does not seat.

 

[EXPjawa]

I've done a couple of the nose cone bay kits so far, none have come out quite as clean as yours (not patient enough with cutting the end off). Nice job.

 

[Jozef]

Got the 2K primer on tonight. Build will be on hold until I get back from a North Woods snowmobile trip.

 

[MikeyDSlagle]

What's the deal with the tail cone? Does it glue to the air frame? Are you just leaving it unattached for finishing? Might want to mask the shoulder to keep the paint and primer off of it if that is the case.

Curious because this is likely my next rocket. Tired of beating around the bush about getting a MAC. Always liked the Ethos so I might as well. I am requesting it for my birthday and if it doesn't show up, I may buy it anyway. LOL Didn't buy a kit all of 2017, so I am due one. I talked to Mike months ago about a 3" Blackfly, but I passed up his latest short run because I saw Ethos was back. So it is about darn time I get one. I'm sure Mike is saying the same. Sorry, end rambling.

 

[mpitfield]

I do, Mike. The shop is a separate room in the basement. A 325 CFM blower is mounted in the rafters and plumbed inside the wall to the paint booth and vented outside the house through 6 inch dryer duct. The booth itself is nothing more than a large packing carton from U-Haul. The back is cut out to fit over the wall vent that goes to he blower. It sits on a plastic stand and can be simply moved if needed. Inexpensive furnace filters line the back wall of the booth to catch overspray

Joe I'm coming down for a paint shop party! Looking great so far.

 

[Jozef]

What's the deal with the tail cone? Does it glue to the air frame? Are you just leaving it unattached for finishing? Might want to mask the shoulder to keep the paint and primer off of it if that is the case.

Curious because this is likely my next rocket. Tired of beating around the bush about getting a MAC. Always liked the Ethos so I might as well. I am requesting it for my birthday and if it doesn't show up, I may buy it anyway. LOL Didn't buy a kit all of 2017, so I am due one. I talked to Mike months ago about a 3" Blackfly, but I passed up his latest short run because I saw Ethos was back. So it is about darn time I get one. I'm sure Mike is saying the same. Sorry, end rambling.

Yes, the tailcone has a shoulder that glues inside the base of the airframe. The center of it also glues to the motor tube. I did mask the shoulder before priming. I am leaving it unattached as the tailcone will be painted black and the rocket will be painted the original Ethos color which is an orange/gold metallic. If you look at Michael Pitfield's Black Fly build, you can epoxy the tailcone to the airframe, fill the seam, then prime and paint. I simply chose to make mine resemble the Aeropak screw on tailcone retainer used on the original Ethos.... which was a 54 mm powered rocket that Mike Crupe flow on K-motors.