Kosdon Nozzles

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emckee

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Hi folks,

While I have seen some information regarding case, nozzle, and liner sizes for larger Kosdon cases (specifically 54+mm), I still haven’t found any information regarding the 24-38mm sizes.

I have recently come into a number of reloads and cases in this size range, so need help identifying the needed nozzle dimensions (particularly throat sizes) for these reloads:

24mm H550
29mm I550
29mm I800
38mm J530
38mm J1500 (same case as the J530)

Please note that I believe these are the older reload classifications, and they were probably updated at some later point.

Any help would be appreciated!
Erik
 
(From 1998 Kosdon data)...
24mm H550 = 0.3770
29mm I550 = 0.3680
29mm I800 = 0.4375
38mm J530 = 0.5940
38mm J1500 (same case as the J530) = 0.5940
 
That table on Tapatalk is what I have been going by for some time, but as I mentioned, it doesn’t have anything below 38mm...

Interesting to hear that it is generally not the original Kosdon specs. Indeed, the 38/1116 nozzle size you have provided does not match the one on the table. Do you have a source that you can share for the original 1998 Kosdon designs?

Also, if I have a reload, how can I differentiate whether it is an AMW/Kosdon East vs a Kosdon TRM reload?

Thanks,
Erik
 
The original Kosdon reloads will just say Kosdon TRM. AMW loads have new propellants and closure designs, so grain lengths and nozzles are different.

I have original design tables from 1998 which can't be posted publicly. But I can spot check sizes as needed.
 
That's mostly AMW/Kosdon East and does not match the original Kosdon motor designs.

I'm going to *mostly* disagree with that statement. I will agree that the table on the TQC forum, while helpful, is not 100% accurate.

The original Kosdon reloads will just say Kosdon TRM. AMW loads have new propellants and closure designs, so grain lengths and nozzles are different.

Every Kosdon load I've ever had/burned, came in the trademark Ziploc baggies with Frank's handwriting on the outside in pen...simply "L1860F-23" for example...nothing more. The grains are generally labeled F, S, DH, or if you're lucky, RP4 or similar. The only instructions I've ever seen were included in the hardware...sometimes. The only place I ever saw Kosdon-TRM in print was in HPR magazines. I've received loads directly from Frank, through a few vendors (Performance H, Red Arrow), and second hand through others that are fans of Frank's stuff.

For the most part, Paul and Jim did not change the throat sizes of the nozzles for a given hardware size; but YES, the Kosdon East/AMW nozzles were a bit longer with the liner step, and the bulkheads were a different design, but the grain lengths remained very similar.
 
That table on Tapatalk is what I have been going by for some time, but as I mentioned, it doesn’t have anything below 38mm...

Interesting to hear that it is generally not the original Kosdon specs. Indeed, the 38/1116 nozzle size you have provided does not match the one on the table. Do you have a source that you can share for the original 1998 Kosdon designs?

Also, if I have a reload, how can I differentiate whether it is an AMW/Kosdon East vs a Kosdon TRM reload?

Thanks,
Erik

Erik,

I'm not much value on many of the sizes you have, unfortunately.

I do have a 1.5-1116 hardware set, which was supplied with a Frank Kosdon nozzle with a .693" throat. Other measured nozzle sizes for Kosdon (not Kosdon East/AMW) 1.5" hardware:

390 (3G): .284"
510 (4G): .316"
640 (5G): .369"
900: .507"
1116: .693"

It appears...your mileage may vary!:)
 
For the most part, Paul and Jim did not change the throat sizes of the nozzles for a given hardware size; but YES, the Kosdon East/AMW nozzles were a bit longer with the liner step, and the bulkheads were a different design, but the grain lengths remained very similar.
[...]
For the most part, Paul and Jim did not change the throat sizes of the nozzles for a given hardware size; but YES, the Kosdon East/AMW nozzles were a bit longer with the liner step, and the bulkheads were a different design, but the grain lengths remained very similar.

No they are mostly not similar. I have all the dimensions for grain lengths and nozzle sizes for all certified Kosdon (pre-AMW) reloads (1998 snapshot). I also have all the specs on the AMW motors. It's nearly impossible to find anything the same other than some case lengths.
 
Erik,

I'm not much value on many of the sizes you have, unfortunately.

I do have a 1.5-1116 hardware set, which was supplied with a Frank Kosdon nozzle with a .693" throat. Other measured nozzle sizes for Kosdon (not Kosdon East/AMW) 1.5" hardware:

390 (3G): .284"
510 (4G): .316"
640 (5G): .369"
900: .507"
1116: .693"

It appears...your mileage may vary!:)

You have to make sure the nozzle was intended for "regular Bates grain" loads or "Special Bates grain" loads. All the reloads Erik asked about are the "Special Bates grain" loads and the nozzle info you listed are for regular loads.

There are also special cases and nozzle combos laying around that Kosdon made that were not certified. Then there's the change a vendor mixed together parts to get rid of inventory. Safest is to go by the as-certified combination of case length, grain specs, formula, and nozzle throat... for the reload class and average thrust. To make it even more confusing, there is the Kosdon designation for the load and the as-certified designation.

The specs for the nozzle throat are nominal drill bit number/letter. So, they may be a little larger "as measured". And larger after they've been used.
 
Wow, good information here. Thanks to all for the contributions.

It certainly doesn't sound like it is as straight-forward as I had initially thought.

John-
Thanks for the clarifications regarding "special" vs "regular" Bates grains, and associated nozzles. I didn't see that one coming. I have a set of the 390/510/640 cases and have a few nozzles that were provided with them, but no details on which goes with which (or, as you said, if the vendor just threw some extra nozzles in to clear inventory). Do you agree with Eric's numbers for standard loads (slow, fast, DH, and C-slot) in these cases?

In the case of the 1.5" x 1116 case and nozzle, my understanding is that there were only two loads for this case: J1500/J975 and J900/J530, which you indicate both used the 0.5940" throat nozzles. Eric indicates 0.693" throat for this case, which you indicate is for the "regular" bates grain... But I don't see another reload for the case which could have a "regular" grain configuration. Can you please clarify?

Lastly, am I correct in the presumption that the KBA reloads will use the standard nozzles/throat sizes?

Eric, Thanks to you also for the information. The differences between yours and John's numbers highlight the challenges associated with using Kosdon motors/reloads in the present day!

Again, thanks to all for the contributions!
Erik
 
Wow, good information here. Thanks to all for the contributions.

It certainly doesn't sound like it is as straight-forward as I had initially thought.

John-
Thanks for the clarifications regarding "special" vs "regular" Bates grains, and associated nozzles. I didn't see that one coming. I have a set of the 390/510/640 cases and have a few nozzles that were provided with them, but no details on which goes with which (or, as you said, if the vendor just threw some extra nozzles in to clear inventory). Do you agree with Eric's numbers for standard loads (slow, fast, DH, and C-slot) in these cases?

In the case of the 1.5" x 1116 case and nozzle, my understanding is that there were only two loads for this case: J1500/J975 and J900/J530, which you indicate both used the 0.5940" throat nozzles. Eric indicates 0.693" throat for this case, which you indicate is for the "regular" bates grain... But I don't see another reload for the case which could have a "regular" grain configuration. Can you please clarify?

Lastly, am I correct in the presumption that the KBA reloads will use the standard nozzles/throat sizes?

Eric, Thanks to you also for the information. The differences between yours and John's numbers highlight the challenges associated with using Kosdon motors/reloads in the present day!

Again, thanks to all for the contributions!
Erik

Good luck, Erik!!!

I had a big response typed out in response to John's last response, but deleted it. I respect you, John, though I totally disagree with several of your statements. :cool:

Not saying you haven't...but I've flown A LOT of Kosdon motors, A LOT of AMW motors, and my "EX" program is based upon Kosdon/AMW/Gorilla/Loki hardware. I've got a pretty decent track record with all of the above. Definitely differences in there, but your claims essentially question everything I ever "knew" about all of the above. So, please understand and forgive me if I disagree with your response(s).

All good, I'll just agree to disagree. Like Erik said, that's part of the challenge (FUN) of flying Kosdon then and now.

Cheers!
 
Good luck, Erik!!!

I had a big response typed out in response to John's last response, but deleted it. I respect you, John, though I totally disagree with several of your statements. :cool:

Not saying you haven't...but I've flown A LOT of Kosdon motors, A LOT of AMW motors, and my "EX" program is based upon Kosdon/AMW/Gorilla/Loki hardware. I've got a pretty decent track record with all of the above. Definitely differences in there, but your claims essentially question everything I ever "knew" about all of the above. So, please understand and forgive me if I disagree with your response(s).

All good, I'll just agree to disagree. Like Erik said, that's part of the challenge (FUN) of flying Kosdon then and now.

Cheers!

If what you're doing is working for you, don't worry about the discrepancies. If there is something specific that you don't agree with, let me know and I'll see if I can try to resolve it. I might be wrong. ;)

The best way to do EX with snapring cases is to understand what you *should* have for grain dimensions, nozzle throat&opening, and good closure designs. What a manufacture supplied is what worked for their goals and might not be best to copy. This is especially true with old Kosdon hardware. AMW redesigned all the closures, and new hardware altogether in some case sizes, because Kosdon's were not very consistent. AMW & Loki have commercial hardware to match what their propellant is/was, and the thrust curves they wanted. Design tradeoffs for mass flux, etc. It's not always best to just clone a commercial load without understand what Burnsim is telling you. This is critically true when cloning AT/CTI loads which used an erosive phenolic nozzle and expecting it to work with a graphite nozzle.
 
The best way to do EX with snapring cases is to understand what you *should* have for grain dimensions, nozzle throat&opening, and good closure designs. What a manufacture supplied is what worked for their goals and might not be best to copy. This is especially true with old Kosdon hardware. AMW redesigned all the closures, and new hardware altogether in some case sizes, because Kosdon's were not very consistent. AMW & Loki have commercial hardware to match what their propellant is/was, and the thrust curves they wanted. Design tradeoffs for mass flux, etc. It's not always best to just clone a commercial load without understand what Burnsim is telling you. This is critically true when cloning AT/CTI loads which used an erosive phenolic nozzle and expecting it to work with a graphite nozzle.

John, we're speaking the same language. I've designed and burned loads in both AT/CTI hardware and Kosdon/AMW style snap ring hardware. For EX, I've had one cato in 177 burns... with a 0.56% failure rate, I must be lucky or I'm not trying hard enough.:)

I should have been more specific earlier...I use AMW/Kosdon/Loki/Gorilla as the basis for the majority of hardware for EX. In other words, I don't clone commercial loads...never have. But I have darn good records of the dimensions to make loads for that hardware (cases: snap ring-to-snap ring length, nozzle: LOA, liner step, throat, bulkhead: LOA, liner step, O-ring sizes for all the above and so on). Sometimes I use the "stock" nozzle and bulkhead, other times not...it depends upon the formula, internal parameters, etc. As you describe, I DESIGN my loads. HOWEVER, since I tend to use a lot of AMW, Kos hardware for my EX program, I *think* I have pretty decent notes on hardware dimensions. Those that have had a glimpse into my "Research Notebook" would probably agree. I tend to be a bit OCD and a documentation nut! And though I have a copy of Burnsim, and do like the program, I designed successful motors for a long time before purchasing a copy. I think I've designed 3 motors in Burnsim; the rest are done using my noggin' and some basic calculations....not too indifferent from Frank's napkin scratchin' style!:wink:

All good!
 
I should have been more specific earlier...I use AMW/Kosdon/Loki/Gorilla as the basis for the majority of hardware for EX.

That's good. Better than using AT/CTI for EX, and easier than making your own hardware. I've been making my own hardware for 20 years. Up to 6" P so far.

But this is not the research forum. The original poster was asking about specific Kosdon reloads and nozzle sizes. You've said you disagree with what I've posted about those nozzle sizes. I'm confident I have the as-certified info on most Kosdon and AMW reloads. Let me know if there is something *specific* you don't agree with and I'll double check what I have.

What I don't have is all the dimensions for the various sizes of Kosdon forward closure or nozzle dimensions (other than throat size). Posting measurements of those would be very helpful to many people trying to use an old Kosdon reload with missing hardware.
 

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