Transitions

[mycrofte]

Does anyone make through-tube transitions? All I can find online are solid balsa.

[tbzep]

Does anyone make through-tube transitions? All I can find online are solid balsa.

You can go two routes. Drill out the balsa transition, or for a larger diameter, make a paper transition. My son and I normally use a shroud generator such as the one on New Century Rocketry's website, and make our own transitions. I don't know if anybody has paper transition kits or not, but it shouldn't be much trouble to look it up on Semroc, Fliskits or other manufacturer websites.

Drilling the balsa is easy as pie. Just don't try to drill such a big hole that you end up getting close to the edge of the smaller diameter section.

[mycrofte]

Yeah, that's the problem with the balsa drilling. I need it to be about 1/16 around the narrow end. Unless I buy a bigger size and sand it down on the outside as well.

I have tried a few of the paper generators. The one I downloaded isn't very accurate for short transitions. I am trying an online version and looking at others.

[Carl@Semroc]

The "easiest" way is to drill it before turning it. :D

What transitions are you looking for that are drilled?

[mycrofte]

I'm looking for BT50 to 55 transitions with a BT-20 hole through it. Which cuts it real close on the BT50 side. According to the 1" and 1.5" transitions I've looked at. And I don't have the equipment to do something that close.

[Carl@Semroc]

I'm looking for BT50 to 55 transitions with a BT-20 hole through it. Which cuts it real close on the BT50 side. According to the 1" and 1.5" transitions I've looked at. And I don't have the equipment to do something that close.It would be very thin. We do the BTC-55Z tail cone and the base of it is about .93" so I know it can be done. How many do you need? TA-5055 or TA-5055L?

[mycrofte]

Actually I have a couple of designs in mind that could use them. Both the TA-5055 and TA-5055L. So, 3 each would cover my needs for about the next 6 months.

Unless there is an easier way to run a BT-20 up to a front pod!?! I've been wanting to experiment with coke bottle shape rockets. I guess it would actually be inverted coke bottles. Similar to the GOONYDENT but with the BT-20 running through the middle.

[sandman]

Actually I can drill them while they are still on the lathe.

Also I can make it any length you would need.

[mycrofte]

What kind of cost are we looking at for pieces just like the TA-5055 and TA-5055L drilled out for a BT-20?

[sandman]

What kind of cost are we looking at for pieces just like the TA-5055 and TA-5055L drilled out for a BT-20?

$12 each plus shipping.

I can make them a bit long, shorter, an ogive shape, a stepped shape or even a convex shape.

[mycrofte]

I'm afraid I'll have to stick with the paper transitions for now. That would be $24 per rocket for something I'm not even sure will work at this stage.

[Carl@Semroc]

mycrofte,

Send me your shipping info to sales@semroc.com and we will send them out tomorrow.

TA-5055D (http://www.semroc.com/Store/scripts/prodView.asp?sku=ta-5055d)
TA-5055LD (http://www.semroc.com/Store/scripts/prodView.asp?sku=ta-5055ld)

[mycrofte]

Yeah, those look like what I need!

Thanks!!!

[KD5NRH]

I'm looking for BT50 to 55 transitions with a BT-20 hole through it. Which cuts it real close on the BT50 side. According to the 1" and 1.5" transitions I've looked at. And I don't have the equipment to do something that close.

It seems odd that nobody makes a transition designed to slip over the smaller tube, since that would leave the entire inner space available. Putting a third, smaller tube down the middle is easy enough with centering rings.

[sandman]

It seems odd that nobody makes a transition designed to slip over the smaller tube, since that would leave the entire inner space available. Putting a third, smaller tube down the middle is easy enough with centering rings.


They do, well, I do it's called a tailcone but if you put it in the middle then it's a transition. :D

This is the tail cone for the Sprint but I can make any size.

[KD5NRH]

They do, well, I do it's called a tailcone but if you put it in the middle then it's a transition.

DOH!! I never even thought to look at tailcones when I was looking for a hollow transition. :(

[mycrofte]

Yeah, I never thought of looking into boat tails either. Here is what I did with two of the hollow transitions I got from Semroc. Made it easy to connect the top and bottom of a "home grown" Nike Hercules and allow the ejection charge to go up.

http://i629.photobucket.com/albums/uu15/Mycrofte/Current%20Build/PHOT0135.jpg

[Chris_Timm]

I'm looking for BT50 to 55 transitions with a BT-20 hole through it. Which cuts it real close on the BT50 side. According to the 1" and 1.5" transitions I've looked at. And I don't have the equipment to do something that close.

Wouldn't the plastic tail cone from the estes Bullpup kit work for you?
Big diameter is bt-55, has a bt-20 going thru it. Just use a bt-5020 ring and you're set to extend the smaller diameter (bt-50) however long you wish.

[mycrofte]

I don't know. I've never seen one.

[Intruder]

It's just an ordinary, average BT-55 to BT-50 plastic transition that you have to hack into a boat tail.

[Chris_Timm]

Any hints on what you are thinking of building that requires the hollow transition?
If its for venting to ignite an upper stage, you can still line a hollow plastic transition with a foil-lined tube to help protect it.

[mycrofte]

Same as before. I would need a ready source of the plastic transitions. My main use for them is that it makes it easy to transition from an engine size tube to something else without loosing the ejection charge.

If you block off the lower section with a solid transition you have very little space left for a parachute. As you can see in the picture of my single engine Nike Hercules, passing the BT-20 tube through to the upper section made that real easy.

Plus it gave me room in the upper section for a baffle. Not that it can't be done other ways. It just seemed a whole lot easier to me. I didn't want to mess with a 4 engine cluster and an expensive transition to divert the ejection through. Seemed like a lot of hassle for something that can be done simpler.

[Rocket Doctor]

Same as before. I would need a ready source of the plastic transitions. My main use for them is that it makes it easy to transition from an engine size tube to something else without loosing the ejection charge.

If you block off the lower section with a solid transition you have very little space left for a parachute. As you can see in the picture of my single engine Nike Hercules, passing the BT-20 tube through to the upper section made that real easy.

Plus it gave me room in the upper section for a baffle. Not that it can't be done other ways. It just seemed a whole lot easier to me. I didn't want to mess with a 4 engine cluster and an expensive transition to divert the ejection through. Seemed like a lot of hassle for something that can be done simpler.

What sixe plastic transistion do you need? I might be able to help you out. PM me with the details.

[mycrofte]

None now that I have the balsa transitions. But, I mainly use 'B' and 'C' engines and BT-55 tubes seem to fit most of what I want to build. So, anything that works like the 5055 transitions that I can run a BT-20 through will work.

Carl thought it was a good enough idea to add to Semroc's line so I'm covered unless you know of some good plastic parts.

[Chris_Timm]

Quest Aerospace has an affordable plastic hollow reducer coupling but its metric sized close to your needs.

30mm to 25mm or roughly BT-55 to BT-50.
And only 50 cents each!!!

http://www.questaerospace.com/itemdesc.asp?ic=21061&eq=&Tp

[mycrofte]

I'll have to look into that. Being plastic, I can always sand it or take the Dremel to it.

[KD5NRH]

Quest Aerospace has an affordable plastic hollow reducer coupling but its metric sized close to your needs.

30mm to 25mm or roughly BT-55 to BT-50.
And only 50 cents each!!!

Oooh! And the 3525 is pretty close to being BT56-BT50...could make a good tailcone for the BT56 AMRAAM I've been thinking about. (For some reason, I have a plastic BT56 nosecone laying around that looks about right for an AMRAAM...and keeps deceiving me into thinking it's a BT55 cone, so I need to get it mounted on something so I'll quit misinterpreting my parts pile...yeah, that's a good excuse for building another rocket :D )

[Rocket Doctor]

None now that I have the balsa transitions. But, I mainly use 'B' and 'C' engines and BT-55 tubes seem to fit most of what I want to build. So, anything that works like the 5055 transitions that I can run a BT-20 through will work.

Carl thought it was a good enough idea to add to Semroc's line so I'm covered unless you know of some good plastic parts.

I should have the 5055 plastic Estes transistions that you are looking for. If you only need a couple, I think I cna help you out.