Composite low power motors?

[isobig]

Hi all! I was wondering why the smaller motors such as A-D are only available in black powder. I would love to see an option to get them in AP. Anyone know the reason? I am assuming economics, but could be other reasons that I am not aware of.

Thanks!

[DeeRoc29]

http://www.hobbylinc.com/aerotech_d_...rocket_engines

[Barracuda]

hobbylinc has D9 thru 15's in reloads..most are out of stock though.That's the smallest I've seen in composites.

[DeeRoc29]

Sorry, didn't see HL was out of stock. Try Apogee http://www.apogeerockets.com/Rocket_...ors_Single_Use

[Coop]

Not too long ago, I was lamenting the unavailability of 13mm B and C motors... the smallest composite of which I'm aware is a D. Seems economics is the driving force --that there really wouldn't be too much of a market for them --which I personally find unfortunate, but oh, well... no one ever asked me.


Later!

--Coop

[MarkII]

AeroTech used to make B and C reloads for the RMS 18/20 motor. The discontinued them because of poor sales.

[MarkII]

Not too long ago, I was lamenting the unavailability of 13mm B and C motors... the smallest composite of which I'm aware is a D. Seems economics is the driving force --that there really wouldn't be too much of a market for them --which I personally find unfortunate, but oh, well... no one ever asked me.


Later!

--Coop

There are others out there who share that desire. Unfortunately they are apparently too few in number to sustain a product line.

[luke strawwalker]

Hi all! I was wondering why the smaller motors such as A-D are only available in black powder. I would love to see an option to get them in AP. Anyone know the reason? I am assuming economics, but could be other reasons that I am not aware of.

Thanks!

Years ago there were smaller reloads, at least in B and C sizes, IIRC... they were never terribly popular because, quite frankly, it's hard to compete with BP motors on price point at that size... PLUS you have to have the reload hardware, and if the rocket gets lost with your case in it, that's a VERY expensive flight indeed! They were never big sellers apparently and thus went away.

As I understand it... Later! OL JR

[rockets4kids]

Given the semi-automated way that APCP grains are produced, it takes about the same amount of time to make a A-D class grain as it does an E. In fact, smaller grains can actually be quite difficult to produce. The major component of small reload cost is time, not materials, so everything in the A-E class costs effective the same to produce. When motors are priced according to impulse, there is very little profit on small motors. When they are all priced the same (that is, with a similar mark-up) very few people will opt for an A-D motor when they can get an E for the same price.

[DeeRoc29]

If you really want a composite A, B, or C motor, you should make them yourself.

[cwbullet]

I have come c motors from aerotech that are no longer certified.

[RoyAtl]

Twenty years ago, there WERE composite B and C motors (there are current D motors from Aerotech, two single use (D10 and D21), and two similar reloadables (D13 and D24), with an occasional long burn D motor made for glider flights).

The B8 motor was made in a 13mm case for Apogee Components when it was owned by Ed LaCroix. $8 per motor. Most popular use was for competition egg lofters.

Aerotech also made a C motor -- C10, i think -- for Apogee sometime in the past decade.

Aerotech also made (or at least offered), A, B, and C reload kits for the 18mm reloadable casing. These never, uh, took off.


Composite motors are generally hand-made, and are labor-intensive, so the cost of making a B composite is near the cost of making a D composite, possibly even more. Not that many people want to pay $10 or more for a single B motor.

[Disaster_Guy]

It would be nice if there was a slightly larger selection of motors for the 18/20 case. The current selection of only two motors (D13/D24) just doesn't justify the cost f the hardware in my mind. For the rare times that I need a D motor in an 18mm bird the D21 works. One thing of note... While Apogee lists both the D10 & 21 single use as in-stock, AT's online store only lists the D21 making me wonder if the D10 is headed OOP (not that I have ever used one or had a need for one).

[RoyAtl]

While Apogee lists both the D10 & 21 single use as in-stock, AT's online store only lists the D21 making me wonder if the D10 is headed OOP (not that I have ever used one or had a need for one).

Those are sold on ValueRockets.com, not the regular AeroTech site.

[Rocketjunkie]

Apogee used to have 13 mm B7 and C6 motors. In 18 mm they had C4, C10, and D3. I believe they still have the 24 mm E6 and 29 mm F10's.

[Coop]

I understand the logistics and economics... just wish it were not the case, because 13mm B and C's would be wicked.

I've got a few of the D-10's --they really wake up some of the Estes kits. DRM on a D-10? Yes, have some!



Later!

--Coop

[cwbullet]

I really do think now would be the time for more 18 mm motors. Rocketry is becoming more and more popular. I think it will continue to grow as the economy improves

[JPVegh]

HA! It's like deja vu all over again. Seems like every six months or so we have a similar thread.

It was about 3-4 years ago that Gary R posted a teaser thread over on YORF asking if there was any interest for Aerotech bringing back some of the LPR reloads for the 18/20 motor. Of course there was great interest in having that happen and folks got all excited. Then he posted a youtube video of a D3 test and that generated a bit more excitement. A little over a year ago I posted a question on the AT FB page asking if the D3 was still a go and got a reply that we might see it early next year. Well so far all we have seen is a bunch of vaporware. I'd love to see the C4 and C12 back in production as well a D3 reload.

[cwbullet]

Vapor wear is terrible. I understand though if it is not profitable.

[JPVegh]

Vapor wear is terrible. I understand though if it is not profitable.

Oh I agree, if you can't make a profit then why would you do it. Apparently the 18/20 isn't doing so well because fewer and fewer vendors are carrying the motor and the reloads. I've bought about a dozen reloads for mine in the past 2 years and I know a few other people who have bought reloads but I guess the sales just aren't there. It's a shame because when you think about it an 18mm reloadable motor is a very cool thing. I'd really hate to see support for this motor go away.

[ClayD]

HA! It's like deja vu all over again. Seems like every six months or so we have a similar thread.

It was about 3-4 years ago that Gary R posted a teaser thread over on YORF asking if there was any interest for Aerotech bringing back some of the LPR reloads for the 18/20 motor. Of course there was great interest in having that happen and folks got all excited. Then he posted a youtube video of a D3 test and that generated a bit more excitement. A little over a year ago I posted a question on the AT FB page asking if the D3 was still a go and got a reply that we might see it early next year. Well so far all we have seen is a bunch of vaporware. I'd love to see the C4 and C12 back in production as well a D3 reload.

I think one of the major hurtles to overcome is that the(quest/estes) BP motors can be purchased by minors, and arent (explosives). Whereas the APCP motors are brandished as dangerous, and you have to be 18 to purchase the reloadables.
I don't know what kind of exemptions you would have to get for an APCP single use... But thats probably a big enough pita alone to keep most manufacturers away.

I dont see mass producing APCP single use a major hurtle, other than the beurocratic mushflopping to get it done. RMS is a great deal easier, and you could make more money with it, but then your restricted to adults who probably would be a really limited spectrum, and be (not worth it.)


The fact that you see them come and go, is a clear indicator the market doesnt sustain them. Unless a manufacturer wanted a presence selling them for trinket value, you wouldnt make them as a sound buisness decision.

[cwbullet]

BP is still listed as an ATF regulated product if not in a gun.

[ClayD]

BP is still listed as an ATF regulated product if not in a gun.

what does that have to do with estes and quest rocket "engines".

[cerving]

It costs more to make an AP motor because they have to handle higher temperatures and pressures. If you tried to put AP in a paper/clay casing like the BP motors the nozzle would probably blow out. Nevermind the higher cost of the propellant, I doubt that anybody could make an AP LP motor for anywhere near what Estes/Quest can make BP motors for. I honestly can't see anyone spending $10 for a B motor... even the oldtimers that lament not being able to get a B14 anymore.

[ClayD]

It costs more to make an AP motor because they have to handle higher temperatures and pressures. .

Dont tell that to aerotech... thier econo line are mostlyl paper cases....

[Bazookadale]

Dont tell that to aerotech... thier econo line are mostlyl paper cases....

They are kraft phenolic - not just plain paper

[Bazookadale]

I understand the logistics and economics... just wish it were not the case, because 13mm B and C's would be wicked.

Later!

--Coop

I flew the 13mm motors, they were cool but a bit of a pain to use. The nozzles had to be very small in order to keep the chamber pressure up - AT supplied a super thin copperhead for them but it was still a pain to insert properly, often you had to shave down the pyrogen to get it in.

[Initiator001]

Dont tell that to aerotech... thier econo line are mostlyl paper cases....

Current AeroTech single-use motors use a molded plastic case.

[ClayD]

Current AeroTech single-use motors use a molded plastic case.

Plastic? i wonder if thats okay considering plastic that would be strong enough would probably be frangible like PVC, which is not allowed....

They are kraft phenolic - not just plain paper

paper by any other means, is paper! Kraft paper, is escpecially cheaper than butcher paper...

Looks like RCS still sells the same ole paper phenolic tube they had back when i flew my last SU load back in 99
http://www.rocketmotorparts.com/prod...henoliccasings

Paper/Phenolic Motor Casings
Black convolute-wound XX-grade paper-phenolic tubing
(NOTE: Phenolic tubing will not be shipped outside the U.S.)




Product No. Outside Dia. Inside Dia. Length

18mm Casing
01930L .703" .625" 48"
24mm Casing
01950L .938" .812" 48"

29mm Casing
01960L 1.130" 1.005" 48"

38mm Casing
01970L 1.500" 1.312" 48"

[cavecentral]

I flew the 13mm motors, they were cool but a bit of a pain to use. The nozzles had to be very small in order to keep the chamber pressure up - AT supplied a super thin copperhead for them but it was still a pain to insert properly, often you had to shave down the pyrogen to get it in.

I have enough trouble with E15s.

I do remember seeing a B composite the size of a mini motor. Don't remember if it was AT or another brand. It was more of a novelty than a full production motor.