Suggestions for first HPR

I think a MAC kit would make a great first high power kit. from what I've seen they are a very complete kit with well made parts that don't really require any work. fairly low weight so you get good flights on smaller high power motors. tough and water proof. the down side to fiberglass is it always requires some tweaking and fine tuning. traditionally it was heavy but the new thin wall stuff seems to have remedied that. the down side to cardboard is it isn't very tough and does not do well with rough landings or water. MAC kits seem to be a good compromise.

I scratch built my L1 rocket out of LOC 54mm tubing and hobby store plywood. I fly a 29mm 3-grain CTI case, mostly in the upper G's but sometimes the baby H's. Having just built a Madcow Arcas kit, I think my biggest mistake was not going direct to a 38mm case. That gets you to upper end of G motors on the 1-grain to middle-low I on 3-grains. Get a 3-grain case to start with a couple of spacers and you're good to go with a lot of different options. I'd probably also go back and use an Aeropack (or equal) motor retainer rather than the slightly kludgy sheet metal hooks I use now. That way I could get rid of the forward bulkhead that I used for a thrust plate and have the flexibility to use Aerotech DMS or larger CTI cases as the mood strikes.

I don't know how prices of 38mm motors compare with 29mm, but last I checked they weren't too much different. For the amount of flying I do, it's unimportant. If you're in CA, make sure you know which motors are legal there. I don't think you can fly Loki there due to state regs.

I think it's kinda like buying the right software, then the computer. How big a motor do you want to got maximum? The 54mm 6gxl cesaroni, can go down to a 4 grain motor w 2 spacers. The big 6xl motors are cool, especially the 9.2 second burn mellow. The rocket has to take the extra long case. Think about gps, and nose cone size too. That might help you vet the rocket. You can reduce the 54mm to 38mm also

The verdict!!! (I think)

I am going to place an order for a Loki 38/240 system later today. I went with 38 mm because I figure that I can fly a ton of L1 motors at this size, and I went with Loki because the hazmat fees would eat up any savings that I got from a certification special from AT or CTI. I'll probably take advantage of a certification special for a 54 mm case when I go for L2, because hazmat will be a necessary evil by then.

For the rocket itself, I think I want a Stealth by Binder Design. While I want this rocket to be a workhorse that I can use to learn HPR, I want to love the design too. And those BD designs are just to cool too pass up. Very close runners-up are BD's Excel with dual deploy and and the HyperLOC 300. I like both of these because they have dual deploy, but I figure that I can upgrade the Stealth to DD when I'm ready. Whatever kit I go with, I'll get a 54 mm motor mount, so I can fly the 38 mm engines with an adaptor at my home field, which has a low ceiling and a relatively small field, but then give it more power when I visit MMMS (hoping to go up there in November).

Thanks so much for all of your input. Without this thread, I wouldn't have even considered Binder Design, GLR or MAC. And I wouldn't have known where to start with my choice of engines. Thanks to you guys, my wish list has exploded over the past week. I think I can keep the Stealth + the 38/240 + plus a few reloads near my budget for the short term, but for the long term, all bets are off.

NattyDread said:

I think it's kinda like buying the right software, then the computer. How big a motor do you want to got maximum? The 54mm 6gxl cesaroni, can go down to a 4 grain motor w 2 spacers. The big 6xl motors are cool, especially the 9.2 second burn mellow. The rocket has to take the extra long case. Think about gps, and nose cone size too. That might help you vet the rocket. You can reduce the 54mm to 38mm also

Click to expand...

Actually from the 6gxl you can only go to 5g with two spacers.

Kevin

BDB, you made a fine choice. No shame in that game at all.

The budget is a disaster, but at least my wife is supportive.

I took all of the advice that you guys gave me and then some....



That's a Tyrannosaur by Binder Design with a DD kit and a 38/54 mm adaptor. Two complete Loki 38 mm motors (240 and 480) and my first H-impulse reload. It's going to be a fun Fall.

BDB said:

The budget is a disaster, but at least my wife is supportive.

I took all of the advice that you guys gave me and then some....

View attachment 273514

That's a Tyrannosaur by Binder Design with a DD kit and a 38/54 mm adaptor. Two complete Loki 38 mm motors (240 and 480) and my first H-impulse reload. It's going to be a fun Fall.

Click to expand...

That's a sweet looking pile o' rocket stuff! Congrats, now get busy building! I am envious - I want to expand into Loki motors, but not until the next flying season - too many flights already lined up with existing motors.

Next summer, though - Darkstar Jr. + K1127 = :eyepop:

That looks like a pile of awesome! Be sure to do a build thread.

75Grandville said:

Next summer, though - Darkstar Jr. + K1127 = :eyepop:

Click to expand...

ZOOM!!

BDB said:

The budget is a disaster, but at least my wife is supportive.

I took all of the advice that you guys gave me and then some....

View attachment 273514

That's a Tyrannosaur by Binder Design with a DD kit and a 38/54 mm adaptor. Two complete Loki 38 mm motors (240 and 480) and my first H-impulse reload. It's going to be a fun Fall.

Click to expand...

sweet! all very nice!

One thing I don't see (and you may have hidden in there) is an Aeropack motor retainer. Absolutely worth every penny.

Nice haul!


TA

BDB said:

The budget is a disaster, but at least my wife is supportive.

That's a Tyrannosaur by Binder Design with a DD kit and a 38/54 mm adaptor. Two complete Loki 38 mm motors (240 and 480) and my first H-impulse reload. It's going to be a fun Fall.

Click to expand...

I would also recommend you check the Loki FAQ (McMaster part no. included) and buy the recommended snap ring pliers for those cases. The "old guys" in my club that have been flying snap ring cases for +20 years say the Knipex brand pliers recommend by Loki is the only one worth buying. Hope the budget isn't too busted yet.

Good luck.

+1 on Knipex

I'll third the recommendation for the Knipex pliers. I tried using my cheapo snap ring pliers I've used when working on my cars, and all I managed to do was scratch up my case.

Also, keep your off hand over the snap ring when removing it from the case. I launched one into the field at Pawhuska. Luckily, they're cheap to replace.

My first high power deal was to build an Aerotech kit with a few light modifications like proper motor retention, then load bigger motors into it starting with the H128. It does not take much!

Speaking of Loki, I would probably be a serious Loki user if not for California.

+ 4 for something besides the crappy needle nose pliers that I have. Scott from Loki told me about the Knipex, but I figured my needle nose pliers would work. Boy, was I wrong.

About the Aeropack retainer....I think I'll wait until it is painted to see if my finish-job qualifies for the investment. But if I do go that way, how do I use a retainer with the 54/38 mm adaptor? I assume I buy the 54 mm retainer, but I'm confused about how it would all fit together.

BDB said:

+ 4 for something besides the crappy needle nose pliers that I have. Scott from Loki told me about the Knipex, but I figured my needle nose pliers would work. Boy, was I wrong.

About the Aeropack retainer....I think I'll wait until it is painted to see if my finish-job qualifies for the investment. But if I do go that way, how do I use a retainer with the 54/38 mm adaptor? I assume I buy the 54 mm retainer, but I'm confused about how it would all fit together.

Click to expand...

I would get the Aeropack 54/38 adaptor. It is nicely made and works perfectly with their standard retainer. In fact most of my flights are exactly that configuration.

Aeropack motor mount adapters come with rings that retain the smaller motor with the original thread on cap. The adapters nest, so you can adapt a 54 all the way down to 29mm.

BDB said:

+ 4 for something besides the crappy needle nose pliers that I have. Scott from Loki told me about the Knipex, but I figured my needle nose pliers would work. Boy, was I wrong.

About the Aeropack retainer....I think I'll wait until it is painted to see if my finish-job qualifies for the investment. But if I do go that way, how do I use a retainer with the 54/38 mm adaptor? I assume I buy the 54 mm retainer, but I'm confused about how it would all fit together.

Click to expand...

Ideally you should have the retainer and motor on hand before you start the build. Some retainers may require that the MMT be positioned forward or aft the default position and may be hard or not possible to retrofit. The GLR 54mm tailcone would look great on that kit but before you commit you need to find out if it is compatible with your motor hardware. I can tell you that it will fit the AT, CTI and barely fits the Loki. When I say barely I mean some motor may fit and some fit well, depending on the manufacturing tolerances...it is that close.

Bottom line regardless of which retainer and motor you use, I would recommend mocking it all up dry first then adjusting if necessary, sim it out with the new configuration (if changed), then start the build.

I have one of my Loki cases with a nice scratch in it, that it didn’t need to have, because I thought, "Baaa any old snap ring pliers will do." Well after a few hours looking for snap rings that went "WHING!" and the nice aforementioned scratch, I am the proud owner of two pairs of Knipex snap ring pliers.


As for motor retainers many different methods work. I only buy them if there is not enough room in the rocket to make or install my own. I'm also partial to the Giant Leap slimline retainers they are about the same cost, and I like the look better. I have never been a fan of the the big twist on bottle cap.

The retainers I make are out of 16 gage sheet metal a 1 1/4" hole saw, a jigsaw with a metal blade and some files, and you can whip out some motor retainers in no time. I use them on all my 3" rockets and up, the 38mm size and 54mm size are interchangeable. The 54mm get a bit more cooked but they do pretty good. My biggest piece of advice is make all of you screws and bolts and any other hardware the same as much as possible, that way you can swap parts out between rockets as you need.


TA

The retention supplied with the Tyrannosaur kit gets the job done on AT, CTI, or Loki. The adapter supplied works with said retainer. The only trick to using the adapter is this: Insert motor into adapter. The motor will stick through the top of the adapter. Apply a tape ring above that which will trap the motor from sliding out. Then slide the works into the motor mount tube and secure with the motor retention hardware provided with your kit.

The retention supplied is the Binder Design variation of a Kaplow clip. It gets the job done without a bunch of expensive machined hardware.

Binder Design said:

The retention supplied with the Tyrannosaur kit gets the job done on AT, CTI, or Loki. The adapter supplied works with said retainer. The only trick to using the adapter is this: Insert motor into adapter. The motor will stick through the top of the adapter. Apply a tape ring above that which will trap the motor from sliding out. Then slide the works into the motor mount tube and secure with the motor retention hardware provided with your kit.

The retention supplied is the Binder Design variation of a Kaplow clip. It gets the job done without a bunch of expensive machined hardware.

Click to expand...

I agree, do that, I did knot know it came with a retainer.


TA

Thanks for all of the input. And thanks Mike for throwing in an adapter for this kit. I need to dry fit all of this to figure out how it will all fit together. Hopefully I can get started this weekend. I have huge projects to do for work this week and I need to flip one of our rental properties, but all I want to do is build rockets!

Binder Design said:

The retention supplied with the Tyrannosaur kit gets the job done on AT, CTI, or Loki. The adapter supplied works with said retainer. The only trick to using the adapter is this: Insert motor into adapter. The motor will stick through the top of the adapter. Apply a tape ring above that which will trap the motor from sliding out. Then slide the works into the motor mount tube and secure with the motor retention hardware provided with your kit.

The retention supplied is the Binder Design variation of a Kaplow clip. It gets the job done without a bunch of expensive machined hardware.

Click to expand...

Retention AND adaptor are supplied? Wow! I am so used to buying kits without retention that I did not even think of it when I first responded. Maybe a Binder kit needs to be in my future.

watermelonman said:

Retention AND adaptor are supplied? Wow! I am so used to buying kits without retention that I did not even think of it when I first responded. Maybe a Binder kit needs to be in my future.

Click to expand...

In light of that, I agree. If only they still offered a Raptor........

Banzai88 said:

In light of that, I agree. If only they still offered a Raptor........

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I can still kit a Raptor by special order for $129.99. The one caveat being that it does not conform to our current standards regarding the quality of the instructions and it uses the old Binder Design build method. It does not come with a pre-slotted airframe.

I do intend to bring this kit up to our current standards at some point in the future, but writing the instruction set and doing the CNC files for the fins and airframe slots takes time.

Anyone have a .rkt or an .ork file for the Tyrannosaur?

Banzai88 said:

Anyone have a .rkt or an .ork file for the Tyrannosaur?

Click to expand...

Just struck out at Rocketreviews.com

After I bought the kit, I asked Mike for the file and he sent it to me. I'm just not sure if he wants me to share it here. I suggest emailing him directly.

BTW...I haven't started building this thing yet, and it is killing me. I'm just too busy with work right now. Everything should calm down in a week, so November is going to be the month of the Tyrannosaur around here.