Inexpensive High Power Rocketry

[DigBaddy]

I used the term "cheap" relative to the cost of buying the motor cases for reloads. In general, reloads are not that much cheaper than DMS. The last time I priced them out, the breakeven points varied all over the place depending on motor diameter, but none of the reloads broke even until you hit double digit usage of the hardware. Unless you fly dozens of motors per year, or want to fly a propellant that isn't available in a DMS motor, reloads just aren't worth it...

Don't neglect the potential to sell the cases should someone get out of the hobby or move on to other motor sizes, etc. Take good care of them and the resale isn't bad.

In the same vein as that; buying used cases can make the break even point just a couple flights depending on what a person wants to fly. Being patient can be worth it; deals pop up.

 

[tsmith1315]

Unless you fly dozens of motors per year, or want to fly a propellant that isn't available in a DMS motor, reloads just aren't worth it...

It’s much better than it used to be. When I bought my 38/720 case, the J350 was the only reload for it.

But now with an RAS, that case can fly 19 reloads from 480-720 and 7 from the 720 alone. There’s more than monetary value in there.

 

[High Desert Rocketry]

seriously a K-450 on a reload that costs $4.00????

A KNSB 'sugar' reload. Keep the chamber pressure low and the risk of CATO goes down dramatically. My 4" two grain K-impulse motor with reusable steel nozzle has over ten flights with the same liner and O-rings and the KNO3 and sorbitol propellant ingredients cost me $4...I get the casting tubes and liners free (the liners are reused Aerotech liners that friends give me). The four grain L-1150 reload cost me $8.

This Saturday it will fly on two grains made by a physics professor and one of the students that I taught yesterday at the college where I work. They are coming out Saturday to watch it fly with the grains they cast.

 

[Hobie1dog]

A KNSB 'sugar' reload. Keep the chamber pressure low and the risk of CATO goes down dramatically. My 4" two grain K-impulse motor with reusable steel nozzle has over ten flights with the same liner and O-rings and the KNO3 and sorbitol propellant ingredients cost me $4...I get the casting tubes and liners free (the liners are reused Aerotech liners that friends give me). The four grain L-1150 reload cost me $8.

This Saturday it will fly on two grains made by a physics professor and one of the students that I taught yesterday at the college where I work. They are coming out Saturday to watch it fly with the grains they cast.

I just put you on my "follow" list. I'm going to dive deep into this method once I get this pesky Cert 2 over with. Thanks for getting me excited about being able to afford HPR one day. Keep the videos and launch success reports coming.

 

[DigBaddy]

But now with an RAS, that case can fly 19 reloads from 480-720 and 7 from the 720 alone. There’s more than monetary value in there.

Another good point. There are 24 loads I can use with my 38/480 and a RAS. There are 8 SU <480Ns 38mm AT motors to pick from. That's why I went with that case and a RAS to get myself into 38mm stuff.

 

[Hobie1dog]

It’s much better than it used to be. When I bought my 38/720 case, the J350 was the only reload for it.

But now with an RAS, that case can fly 19 reloads from 480-720 and 7 from the 720 alone. There’s more than monetary value in there.

ok, being ignorant, what's a RAS?

 

[DigBaddy]

ok, being ignorant, what's a RAS?

Reload adapter system. Here's one such item. https://aerotech-rocketry.com/products/product_5a773ba0-68eb-df1a-37bf-817f3077b35a Allows for using smaller loads in a larger case - as long as there is compatibility (which can be hard to figure out sometimes, but I think Apogee has a good chart on that somewhere).

 

[Hobie1dog]

Reload adapter system. Here's one such item. https://aerotech-rocketry.com/products/product_5a773ba0-68eb-df1a-37bf-817f3077b35a Allows for using smaller loads in a larger case - as long as there is compatibility (which can be hard to figure out sometimes, but I think Apogee has a good chart on that somewhere).

learn something new every day, hopefully. thanks.

 

[tsmith1315]

learn something new every day, hopefully. thanks.

Same function as CTI grain spacers.

 

[Chad]

Another good point. There are 24 loads I can use with my 38/480 and a RAS. There are 8 SU <480Ns 38mm AT motors to pick from. That's why I went with that case and a RAS to get myself into 38mm stuff.

that's what i did too, i got a 38/480 case and the adapters. It covers almost everything I typically launch. After about 25 launches using reloads from buyrocketmotors.com (because i can pick those up locally and avoid hazmat) then the case is paid for.

I've been thinking about cost optimized experimental motors and the $4 sugar reloads further up thread really have my interest. I'm ok with a larger initial cost to get started if the ongoing cost is low.

 

[gdjsky01]

I feel your pain.

I bought 95% of all my reloads 10 years ago or more. I have receipts from Performance Hobbies were I got 8 J's for $400. Now it costs $640 or more PLUS $50 shipping. Commercially bought HPR motors are expensive. I mean $80+ for a single J launch? I am confident that Rocketry is considered a rich white hobby. (No don't bother with your opinions - just watch the videos.) That I think someone is marking them up big time... I just can not imagine that it costs $60 bucks wholesale to make a J motor. IMO it's more like $10 in materials bought in quantity. Some labor. Some insurance and shipping. OTOH I understand that ROCKETRY is a TINY market.

I don't think I can make an HPR motor... but I have the people here in Socal that can (FAR). If you want cheap HPR, thats the way to go... except the Kitchen-Aid mixer is not cheap!

EDIT: Honest, the good news is don't worry. Do LPR or MPR. There is a million variations on rockets that are waiting for you to build and fly. YOU DO NOT NEED TO LAUNCH HPR ROCKETS to have a shload of fun in rocketry

 

[Neutronium95]

I bought 95% of all my reloads 10 years ago or more. I have receipts from Performance Hobbies were I got 8 J's for $400. Now it costs $640 or more PLUS $50 shipping. Commercially bought HPR motors are expensive. I mean $80+ for a single J launch? I am confident that Rocketry is considered a rich white hobby. (No don't bother with your opinions - just watch the videos.) That I think someone is marking them up big time... I just can not imagine that it costs $60 bucks wholesale to make a J motor. IMO it's more like $10 in materials bought in quantity. Some labor. Some insurance and shipping. OTOH I understand that ROCKETRY is a TINY market.

The price of AP has gone through the roof in the past few years. Back in the Shuttle days, it used to be around $6 a pound or less, now it's often triple that.

 

[ksaves2]

The price of AP has gone through the roof in the past few years. Back in the Shuttle days, it used to be around $6 a pound or less, now it's often triple that.

I bought a fair amount back then for that price. Had a prefect that bought I believe something like 1200lbs. and I think it was less than 6 bucks a pound. I bought some from him at cost.

Doesn't Artemis use APCP (probably PBAN) strap-on boosters?
If that program fires up, maybe AP production will pickup and perhaps there will be enough to keep the prices lower or at least stable for the "rocket" guys and gals.
Did a quick look online and AP 400 was $14.00 a lb. Ouch! Compared to the olden days. Glad I was able to partake of it. Kurt

 

[Neutronium95]

I bought a fair amount back then for that price. Had a prefect that bought I believe something like 1200lbs. and I think it was less than 6 bucks a pound. I bought some from him at cost.

Doesn't Artemis use APCP (probably PBAN) strap-on boosters?
If that program fires up, maybe AP production will pickup and perhaps there will be enough to keep the prices lower or at least stable for the "rocket" guys and gals.
Did a quick look online and AP 400 was $14.00 a lb. Ouch! Compared to the olden days. Glad I was able to partake of it. Kurt

I don't know many of the details, but I doubt the price is going to go down any time soon.

My understanding is that companies in the US have to use American made AP. The only facility in the US that makes AP can only do large batch sizes, whereas the Europeans have a more flexible facility to make AP for their solid motors. I believe that Northrop Grumman dodges around the restrictions by importing cheaper precursor chemicals, but that they also only make AP for their own products and won't sell it on the open market.

Even if SLS starts flying relatively often, I doubt that AP prices will come down for companies operating on the scale of Aerotech or Cesaroni.

Also, I believe the SLS boosters switched to a HTPB based formulation.

Again, I don't have any relevant expertise, this is all just half remembered information from conversations with people that know a lot more than me about the subject.

 

[cwbullet]

I bought a fair amount back then for that price. Had a prefect that bought I believe something like 1200lbs. and I think it was less than 6 bucks a pound. I bought some from him at cost.

Doesn't Artemis use APCP (probably PBAN) strap-on boosters?
If that program fires up, maybe AP production will pickup and perhaps there will be enough to keep the prices lower or at least stable for the "rocket" guys and gals.
Did a quick look online and AP 400 was $14.00 a lb. Ouch! Compared to the olden days. Glad I was able to partake of it. Kurt

It had doubled in price. I certainly do not see it dropping.

 

[ksaves2]

Well shoot on that! Thanks for the news Kurt