BT20 Baffle
 

This may be a silly question but here goes:

Does anybody make a BT20 based baffle system?
If so, is a baffle that small really reliable?

I have only ever built a single rocket with a baffle system and that one has yet to fly.


Thanks,

I don't know if a commercial one exists, but I put one in my Cherokee Goon, right on top of the motor mount to see just how reliable it could be. The A10-3T's I've been flying have packed a considerable wallop, so it should test it well. I've only had one flight so far, and I don't see any damage to it yet. It is designed with three disks, like Jim's BT-50 sized baffles.

Thanks for the info. I may try to scratch build one.

I am actually thinking about using such a thing on some Estes Starwars stuff that has the flight probes. My thought is that the additional weight forward could do nothing but help these marginally stable rockets. It will also give me a way to mount a more reliable shock cord.

Thanks again,

I (FlisKits) have the materials to make a BAF-20. If there is a desire, I will get right on it.

NOTE: For those of you who have built our BAF-50 and had problems getting that center ring in place properly, I have solved that problem and would implement that solution in the BAF-20.

So, just let me know!
jim

Re: BAF-20s
 

Jim-

If you are ready to produce these things, I am ready to buy a few...

Let me know when you have them ready! I'm also interested in your 'cure' for the assembly difficulties.

Regarding the Cherokee Goon, a similar 'fix' might be to use the center of a EM ring which is normally NOT used, have an inch or so of EM Tube above the centering ring open and punch holes with a standard hole punch near the top of the tube. Coat the inside of the EM Tube with white glue as well as the disc, and glue the disc in place at the top of the engine tube.

That will prevent the ejection charge from 'blasting' through. Coat the inside of the Body Tube (BT-60) with white glue as well, spread around naer the final position of the passage holes with a scrap strip of balsa. You have made your own 'quick-and-dirty' baffle.

PM sent

Enough interested has been expressed (both here and elsewhere) that I am going to get this one out shortly.

I will draw up the baffle plates and instructions this weekend. I would expect to have the plates in by the end of the week and will let folks know when the production kits are available.

Keep watch :)

jim

Due to a back log of orders it took a tad longer to get the samples. But their in, tested and the new production rings are now on order.

I hope to have some information next week about availability.

My only concern with this baffle (and this will be mentioned in the product details) is the possible problems with restricting the air flow in the case of one of these "shot-gun ejectinos" that happen from time to time. That could result in a blown baffle (best case) or split tube (worse case).

Below is a photo essay of the proto construction.

In the second picture you can see my "cure" for the assembly issues on the BAF-50. Looking at pic #1 you can see that each ring has a pair of notches. One wide and one narrow. The wide one is sized to fit onto a length of basswood (0.040" square) that will be provided with the kit.

In picture 2 you can see how the baffle rings are glued to this strip of wood.

Pic #3 shows how you then attached the provided kevlar cord in the narrow notch.

Once dry, you simply slide this whole assembly into the coupler as can be seen in the last 2 pictures.

Stay tuned :)

jim

I've flown mine (based on this design) in my Cherokee Goon a couple of times with hot A10-3T ejections and it's still in one piece. I have it sitting literally on the motor mount, so it's getting the worst possible treatment. Time will tell how reliable these little guys are, but it's looking good so far. BTW, I coated my disks with glue to give them a bit of ablative material to hopefully extend the life for a few extra launches.

Yeah, coating the plates with glue is a great idea.

That's another issue too, the closer to the motor the greater the damage. Baffles are not a "lifetime" item. They wear out over time. The closer to the motor and/or the more motors, the faster it gets used up...