round-rectangle-round transition

round-rectangle-round transition

Post by Paul Alber » Sat, 08 Feb 1997 04:00:00



I need to make a transition from a round BT to a rectangular section
and then back to round again.  The dimentions for the rectagle are
fixed, but the diameter of the both round sections can be almost
any current Estes BT.

Does anyone have any suggestions?
--
-------------------------------------------------------------

     "First things first, but not necessarily in that order."
                                -- Dr. Who

 
 
 

round-rectangle-round transition

Post by Louis P. Catozz » Sat, 08 Feb 1997 04:00:00


Quote:

> I need to make a transition from a round BT to a rectangular section
> and then back to round again.  The dimentions for the rectagle are
> fixed, but the diameter of the both round sections can be almost
> any current Estes BT.

> Does anyone have any suggestions?
> --
> -------------------------------------------------------------

>      "First things first, but not necessarily in that order."
>                                 -- Dr. Who

1. Block of balsa
2. Sharp Knife
3. Sand Paper
--
___________________________________________________________________________
Lou Catozzi                IBM RS/6000 Division          Visual Systems

Tel: (512) 838-4065           Austin, Texas              Administration
                                 --oOo--

 
 
 

round-rectangle-round transition

Post by Larry Basket » Sun, 09 Feb 1997 04:00:00


Quote:

> I need to make a transition from a round BT to a rectangular section
> and then back to round again.  The dimentions for the rectagle are
> fixed, but the diameter of the both round sections can be almost
> any current Estes BT.

Try using a balsa tube adapter with the larger diameter big enough to
cover your rectangular cross-section and the smaller diameter small enough
to fit inside.  Mark the outline of the rectangle on the face of the large
diameter and use a razor saw/Exacto blade to make cuts on into these lines
parallel to the axis of the adapter.  Clean up with sandpaper and sand
down sharp edges as desired--a blended round-to-rectangle transition would
look pretty neat.  You can make a shoulder for the the rectangular end by
using a sanding block on the sides.

You could get a standard balsa adapter from Estes or order a custom one
from Balsa Maching Service.

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      |   |       Larry Baskett
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round-rectangle-round transition

Post by benn.. » Mon, 10 Feb 1997 04:00:00


     Is the scale of the project small enough to use chip board or oaktag
that can be folded into the correct shape?  Sheet metal is folded into
transitions like this all the time for air conditioning ducts.  You could
then reenforce the inside and saturate the skin with epoxy for strength.
If I misunderstood your question and you are looking for the drafting

-------------------------------------------------------------------
PCB Designer for a railroad products company
-------------------------------------------------------------------

 
 
 

round-rectangle-round transition

Post by Robert Maste » Tue, 11 Feb 1997 04:00:00



Quote:
>I need to make a transition from a round BT to a rectangular section
>and then back to round again.  The dimentions for the rectagle are
>fixed, but the diameter of the both round sections can be almost
>any current Estes BT.
>Does anyone have any suggestions?

The way I did it for the MKII Camera Carrier was to use two flat
balsa sheets to make either end of the rectangular bay (wot the
camera lives in) and attach a pair of short lengths of BT60 (or
whatever) to them.

Then take a piece of cardstock (210gsm is enough) and wrap it around
the structure on one side, until you get a smooth-ish transition.

Unroll the card and mark out the contact points, and join the
dots/lines. Use this as a template to construct the shrouds.

Worked for me!

(If you can, it will be easier if you can round the corners of the
endplates a little.)

BTW - What are you going to be doing with it?

-Rob.

--

"Splee three frooKs, biffle preden7ine mass."-Nik, Fodunk of the Glass Sveege
"Will you follow me into death?" - From the Minbari rebirth ceremony, B5. <*>
"...I've seen NTU lights glitter in the dark near the Mail Gate..." P.Gutmann

 
 
 

round-rectangle-round transition

Post by Bob Kapl » Wed, 12 Feb 1997 04:00:00


Quote:

> I need to make a transition from a round BT to a rectangular section
> and then back to round again.  The dimentions for the rectagle are
> fixed, but the diameter of the both round sections can be almost
> any current Estes BT.

> Does anyone have any suggestions?

Can you run the tube thru the rectangular section? If so, just build the box
around the tube. You'd need some "square" centering rings.

If not, build the box, and use stage couplers or balsa blocks on each side
to connect the tubes. These tubes now no longer have to be the same size.

We might be able to come ou with more ideas if we had more details.

        Bob Kaplow      NAR # 18L       TRA # "Abort, Retry, Fail?"