2.6 E-Bay Layout

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Thank you both :)

So it's paper tubes... is brass not good? I was wondering if epoxy would stick well to brass...

Maybe I can roll up some tubes. The threaded rods in my ebay look like 3/16th

Bob
I'm sure brass would be just fine. All my older ebays used those exact same tubes, although I fiberglassed a piece of fiberglass cloth over the tubes and onto the plywood. Same would make the brass tubes extra secure.

Reason you probably will see many people using those tubes is they were handy. That's what the igniter used to come in!
 
I have a bunch of 3d printed av bays, including 9volt, micro switch, and perfect flight. Happy to print something for you if you want. Just let me know the spacing between the all thread on your Bulkheads. Or even just a piece that screws to your plywood.
 
That printed sled is very cool. I hope to get there someday. And thank you for the generous offer but I kinda want to move forward with the stuff I have for this rocket. I know I won't be spending $30 plus for another of these e-bays.

So anyway, I tried my hand at making some paper tubes yesterday morning. The material used was regular printer paper and Elmer's white glue. The top two were rolled like you'd roll a cigarette using a 4 inch wide piece of paper. They came out a little wrinkled and seemed heavier than needed. The bottom two were spiral wrapped like a body tube using 3 pieces of 1/2 inch wide strips of paper. I liked the spiral wrapped better so I brushed on some laminating resin and let them sit overnight. This morning I sanded them a bit and cut them to length. I am going to go with them. Sled Straw.jpg

Thanks again for all the help, suggestions and offers,
-Bob
 
I had a productive weekend with this project. We had our monthly launch on Saturday and that is when I discovered the paper tubes that hold the ignitor for 29/40-120 reloads fit the all thread very well.
Ignitor Tubes.jpg

I also plugged the old holes in the bulkheads and got the new holes drilled
Modified Bulkheads.jpg

I was all excited to actually start assembling the e-bay today and then I ran into a problem. I thought I would tack the tubes on the plywood sled with CA then run a fillet of epoxy down each side. The CA didn't want to hold the tube in place so I took a closer look and found the plywood sled is warped.
Sled Warp.jpg

I don't feel it's worth the effort to try to straighten out. Looks like I need to cut a piece out of some 1/4" ply I have at home.

Not very happy and wishing I had taken Kramer714 up on his offer to print one for me. I'd still like to know about the switch his sled is designed for...

Very sad in Alamogordo :(
Bob
 
I had a productive weekend with this project. We had our monthly launch on Saturday and that is when I discovered the paper tubes that hold the ignitor for 29/40-120 reloads fit the all thread very well.
View attachment 685074

I also plugged the old holes in the bulkheads and got the new holes drilled
View attachment 685075

I was all excited to actually start assembling the e-bay today and then I ran into a problem. I thought I would tack the tubes on the plywood sled with CA then run a fillet of epoxy down each side. The CA didn't want to hold the tube in place so I took a closer look and found the plywood sled is warped.
View attachment 685076

I don't feel it's worth the effort to try to straighten out. Looks like I need to cut a piece out of some 1/4" ply I have at home.

Not very happy and wishing I had taken Kramer714 up on his offer to print one for me. I'd still like to know about the switch his sled is designed for...

Very sad in Alamogordo :(
Bob
Save some weight and use 1/8" ply. There is no recovery stress to the board. I have even used electric perf boards for sleds. No issues.
 

kramer714


I wanted to ask what kind of switch is that on the printed sled?

-Bob
micro switches like Amazon Micro Switches these.

I use the ones with the lever on the m and cut the lever to the length of the switch. That way if you use too long of a screw you cant push into the switch, it stops before you can.

i have done this with just tapping the 3d print and also using a heat set insert.
 
micro switches like Amazon Micro Switches these.

I use the ones with the lever on the m and cut the lever to the length of the switch. That way if you use too long of a screw you cant push into the switch, it stops before you can.

i have done this with just tapping the 3d print and also using a heat set insert.

I was ready to buy a pack, but then wondered; how is the quality in that Amazon switch? Has your use been OK with them?
-------------------------------------------------------------------
Some of the ratings show fail open, and even one saying it pushed in, but would not pop back out keeping the circuit active.

I was lucky in that my failures of the 0/1 rotary switches always failed open on the ground just when I tried to turn them on in the field.

I have 2 larger AV-bay's switch bands with lots of them in it, as I added more to replace the faulty ones that were glued in, as a field replacement when one failed.
 
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I was ready to buy a pack, but then wondered; how is the quality in that Amazon switch? Has your use been OK with them?
-------------------------------------------------------------------
Some of the ratings show fail open, and even one saying it pushed in, but would not pop back out keeping the circuit active.

I was lucky in that my failures of the 0/1 rotary switches always failed open on the ground just when I tried to turn them on in the field.

I have 2 larger AV-bay's switch bands with lots of them in it, as I added more to replace the faulty ones that were glued in, as a field replacement when one failed.
one thing I have found out, if you 'over push' the button they can stay closed, the solution is to use the switches with levers, and just cut the lever to just past the button.

Pictures below


1735052275729.png

1735052351145.png

1735052666743.png

1735052751958.png

1735052892610.png
 
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