I need some more motor mount tubes, 54mm and 76mm .. anyone got any they want to sell/donate? I'd like to get them for this weekend if possible.

Thanks! Steve

Steve
I checked all the tubes on the wall tonight. Well....if you need coupler material Im your man. 😥 I have 3-3foot sections of each, 54 and 75....coupler. 😕 Evidently bought the wrong stuff, a couple a years ago. CRAP!!! 😕

ANY BODY NEED ANY COUPLERS ? 😀 I have enough for 20 rockets or so.
Could build rockets out of it ........ dont plan on minimum diameter though. 😉

Since this will be a research flight with the O-motor - are you looking at doing research motors for everything else?

If you want to do the 75mm 2/3 grain motors I could volunteer the machining if the project bought the materials. Doing 5 motors is not much more work than doing one once the lathe is set up. Maybe people who'd like could purchase a motor at cost and then use it in the flight and then later use it for personal flights.

Edward

Thanks Edward .. I believe I will be going with something in the 54/1750 range in the booster outboards. What are the material costs for something like that .. complete motor/each? I can post this idea on the EX forum and see what kind of response I get.

Thanks!

Strongly suggest moonburners or endburners for the outboards.

54mm is the one size that is more economical to buy the casings. You will get much more interchangeability with drawn 2.125 x .095 wall tubing than you will turning a bunch of pipe for 54mm.

That is one reason I suggested 2/3 grain 75mm motors. The tubing is available and very inexpensive. Also, it would cut cost to if you didn't use 75mm motor mounts and instead did centering rings for true 3" motors (like the old, old Kosdon 3" motors).

75mm will also give you a longer burn and more show.

A moonburner or endburner is an excellent idea Warren. The problem is that those take time to engineer and get right and the project doesn't really have the time to do all the characterizations and test firings to ensure you have a set of competent, reliable motors. End and moonburners are great in theory, but don't transfer well to our aluminum cased hobby motors.

Edward

Edward, Fort Collins is much more accessible from Wellington than Longmont for frequent trips. Is there something I can do to help or at least come and observe when you make motors?

54mm is the one size that is more economical to buy the casings. You will get much more interchangeability with drawn 2.125 x .095 wall tubing than you will turning a bunch of pipe for 54mm.

That is one reason I suggested 2/3 grain 75mm motors. The tubing is available and very inexpensive. Also, it would cut cost to if you didn't use 75mm motor mounts and instead did centering rings for true 3" motors (like the old, old Kosdon 3" motors).

75mm will also give you a longer burn and more show.

A moonburner or endburner is an excellent idea Warren. The problem is that those take time to engineer and get right and the project doesn't really have the time to do all the characterizations and test firings to ensure you have a set of competent, reliable motors. End and moonburners are great in theory, but don't transfer well to our aluminum cased hobby motors.

Edward

Yea, I thought that might be the case .. but thought I would find more EX'ers interested in a 54mm case than a 75mm one .. I could be wrong.

How much are we talking per case for something in the 75/1700 range?

I am looking for a long burn, but not too long. The main motor will burn say 5-6 sec .. having low thrust outboards burning 10-12 sec might be overkill. I think an 8 sec burn in the outboards will be fine.

Rough Estimate without quotes -

Case - $30
Closure - $10
Nozzle -$30
Snap Rings/Nozzle Washer/Thrust Ring - $15

$85 materials.

If you want it turned to 75mm instead of true 3.00" it would be ~$1 per inch. I much prefer not to turn down casings.

Edward

By the way, I have both Loki and AMW 1750 cases.... I'm not sure if the Loki is 1750, but it is close and I have a K250 moonburner load I'd donate.

Oh wait... 1/2 bates grain fast burn and 1/2 moon or end burners for the outboards..... I've got one of each I'd donate to the project.

By the way, I have both Loki and AMW 1750 cases.... I'm not sure if the Loki is 1750, but it is close and I have a K250 moonburner load I'd donate.

Thanks Warren, I think I am going to go with the AMW/Gorilla 54/ 1750 case style and James and I will build the motors. I can get a good discount on cases from my friend back east .. if not locally. Gorilla and AMW are cross certified so they can still be flown commercially. I'll see how many I can borrow and then buy the rest. After the launch I will sell them at discount as well. btw, my understanding is Jeff went with different sizing .. his is 54/1600 .. which might be usable in this 'EX' format .. I'll ask James.

After meeting with James Russell today we have agreed on motor options for the 1st Proton M flight.

The booster will have a central 98mm mount and 3 - 75mm mounts. The outboards with have 54mm mounts. The sustainer will have a single 98mm mount that will be adapted to 75mm for the initial launch.

James and I, with help from a few of you, will build all the motors (propellant). We will launch on 3 - M1350 (or so) and 6 - K550 (or so) motors. The K's will light after movement is detected. Initial SIMs show stage separation at about 3000 ft with the sustainer topping out around 9000ft.

Motors will likely be a mix of Red and White formulas.

All of this is of course subject to change but I feel good about these numbers and this option will greatly reduce the cost of motors. We have all the large motor cases taken care of and just have to work out the K motors now.

This should be an awesome flight!!

Think I'll go up to Longmont and do some more glassing tomorrow (Sunday) if anyone is interested.

Perhaps another option would be to stick with the EX motors for the 75mm mounts, but go commercial for the 54mm mounts. You could go with 6 grain Cesaroni cases and use either the 6 grain K260 "Classic Longburn" reload (8.7s burn), or the 5 grain (with a spacer) K261 "White Longburn" (7.8s burn) reload. Theres a 4 grain long burn (K160, 9.7s burn) also if you need to keep the total impulse down to the K550 range.

The advantage is that you can get long burn motors without some of the EX hassles with long burners mentioned above, and you'd be using cases that would be very easy to resell (or even get people to buy them in advance, something I would be willing to do). Not to mention the fact that Cesaroni motors are very simple to prep. I would also bet that you could find some club members who would be willing to loan their Pro54 cases to the project.

John Marvin

This sure is stacking up to be one hell of a MHM.

Just for the record. I have a new camera this year. Better
pictures and better video.

1080 and lower HD and slow motion.
Continuious and burst still shooting
Better zoom.

But remember it is sitill I that will be operating it.
I am still on a learning curve.

getting pumped up already.

Perhaps another option would be to stick with the EX motors for the 75mm mounts, but go commercial for the 54mm mounts. You could go with 6 grain Cesaroni cases and use either the 6 grain K260 "Classic Longburn" reload (8.7s burn), or the 5 grain (with a spacer) K261 "White Longburn" (7.8s burn) reload. Theres a 4 grain long burn (K160, 9.7s burn) also if you need to keep the total impulse down to the K550 range.

The advantage is that you can get long burn motors without some of the EX hassles with long burners mentioned above, and you'd be using cases that would be very easy to resell (or even get people to buy them in advance, something I would be willing to do). Not to mention the fact that Cesaroni motors are very simple to prep. I would also bet that you could find some club members who would be willing to loan their Pro54 cases to the project.

John Marvin

Thanks John .. I did consider commercial for the outboards, including CTI, but the cost factor is just too much. I can build the "K"s for around $20/each, compared to $120-$150/each for CTI. Plus I can sell the AMW cases to commercial or EX flyers and CTI is only commercial.

Also, my main motors (M's) will likely burn around 5-6 sec .. I don't want the outboards to burn much past that as the outboards alone, especially something like a K160, will lack the thrust needed to keep the speed up and it will slow down 'fast' with all the drag on a design like this. It is critical on a 2-stage like this that we are going straight up at separation and sustainer ignition.

Before you worry about commercial motor costs, why not have Joe Hinton talk to Dr. J at Cesaroni and see if we can get some comp'd motors or at least motors at cost? Cesaroni has been quite free in the past.

By the way, I do have an AMW 54/1750 and 54/2550 cases that you are more than welcome to use for this project. I'm sorry if I haven't taken the kind of dive into this project that I did with the Delta II, but got a lot of shit going on right now to take on such a large project. If you need sub-systems such as fins or couplers, ebay, etc. laid up and vacuum bagged, I'd be glad to do it. Can't commit to much more.