Custom 38mm Kosdon Bulkhead with Loki/AT Delays

I assume a lot of you out there have Kosdon 38mm hardware from the great sell off from a couple of years ago when Frank passed away. Some came with internals, some didn't. If you're without a bulkhead or are unable to make or source appropriate delay grains, these are for you. I took it upon myself to modernize Frank's design slightly by doing the following:

• Same external dimensions as Franks original bulkheads, making them plug and play with what you have
• Reduced the delay cavity from 7/8" ID to 3/4" ID to accept Loki and Aerotech delays for tracking smoke
• Reduced the threaded portion (powder well for Frank) from 1/2-13 to 1/4-20
• A 3/32" hole passes through the cavity into the threaded portion to allow you to install the delay without compressing air in the cavity.

You can buy delay and o-ring assemblies from Scott at www.LokiResearch.com, or full delay sticks and o-rings from RCS at www.rocketmotorparts.com. The delay well is 1" deep. I do not recommend using EX bulkheads for motor ejection, and therefore recommend installation of a delay with greased fore end and a bolt or eyebolt to prevent any blow-by.

I am asking $50 shipped each for these custom parts. If interest exceeds the 2 that I have made, more can be made to order.

Any interest in these? Wrong price? Want complete motors?

Can you make some that are plugged and shorter?


JD

patelldp said:

Any interest in these? Wrong price? Want complete motors?

Click to expand...

patelldp said:

Any interest in these? Wrong price? Want complete motors?

Click to expand...

Ahhhhh,

I'd try to make sure you get the word out to as many potentially intrested parties as possible Dan.
A one day post isn't likely to be seen by that many.:wink:

Kurt

JDcluster said:

Can you make some that are plugged and shorter?


JD

Click to expand...

Hi JD,

Shorter I can see but to plug it, just stick a screw/eyebolt in. You need a lower profile for an extreme purpose? Like cramming in as much propellant as possible?:grin:
Kurt

As you may know already; the bulkheads are actually thread NTP where bolts are typically SAE.
They fit but not intended use.

I don't use smoke and use it as an attachment point with 1/4"-20 eyebolts.

JD

ksaves2 said:

Hi JD,

Shorter I can see but to plug it, just stick a screw/eyebolt in. You need a lower profile for an extreme purpose? Like cramming in as much propellant as possible?:grin:
Kurt

Click to expand...

ksaves2 said:

Hi JD,

Shorter I can see but to plug it, just stick a screw/eyebolt in. You need a lower profile for an extreme purpose? Like cramming in as much propellant as possible?:grin:
Kurt

Click to expand...

Yea, greasing a bolt or eyebolt and threading it in there is as good as making it sealed.

I could make a shorter version, much like an Ellis bulkhead.

JDcluster said:

As you may know already; the bulkheads are actually thread NTP where bolts are typically SAE.
They fit but not intended use.

I don't use smoke and use it as an attachment point with 1/4"-20 eyebolts.

JD

Click to expand...

Ok,

I see what you mean. Stupidhead here had small caliber AT plugged (with no threaded bolt) bulkhead on the brain. No hole and no fun trying to stuff a smoke grain in without some sort of pressure relief. I've always thought that an eyebolt on a threaded closure was for just having something to grab onto to get the closure
out of the spent motor casing. This after seeing two different rockets come apart during recovery when the shockcord connected to the forward closure eyebolt.
Unscrewed it out so it came in butt end ballistic. Of course it was mentioned on the board to prevent that just use a jam nut or an allen set screw if possible to drill and
thread for the set screw. Kurt

Kosdon's, or at least the ones that I have, are 1/2-13 SAE.

Do you want Kosdon dimension (1.8" long) bulkheads without a delay cavity and a 1/4-20 thread on the outside? Do you want them shorter? I can do either, but how many would you want?

If you're looking to drum up sales I would post these on the Facebook "Tripoli Rocketry Association", National Association of Rocketry" and "Rocket flights around the world" groups. I think I get more hits there than I do off of TRF. You could also start a business page and share posts from it to those groups. I have about 75 followers on my APE page:

https://www.facebook.com/AtteberyPerformanceEngineering?ref=hl

Great idea, Chris. I created a page on Facebook!

https://www.facebook.com/PatellManufacturing

patelldp said:

Great idea, Chris. I created a page on Facebook!

https://www.facebook.com/PatellManufacturing

Click to expand...

Liked and following!

DRAGON64 said:

Liked and following!

Click to expand...

Thanks!

I'm certainly not a full fledged business, but I figured it was time to use Facebook to share my work and sell some items.