Wooden or 3d printed ebay

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AtomicStorm

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Do you want that 3D Printed?
I have a et quantum, so i dont think it would fit that design. Theres one i really like on thingiverse thats very basic.
 

AtomicStorm

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The cheapest place i have found to 3d print stuff for me is the ups store a few states away. I just email the details and they print it out and ship it to me.
 

AtomicStorm

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Im now leaning on building it from wooden dowels or driveway markers for rods and couplers for the bay. I would really like the 3d printed one but i have spent way too much on the last couple builds getting bp, motors, e-matches, ripstop nylon, cordage, altimeters, etc. So if i can make it ill try doing it.
 

Jowayen

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So you have the charge on the inside of the bay? Thats a cool design!
Yes. The Centrifuge tube slips in from the outside and bottoms out on the lip. Since they have a slight taper, it seals itself airtight.
It keeps the igniter wires super short. This eliminates terminals, eliminates extra connections, and eliminates extra wires.

Do you want that 3D Printed?
If you're offering, I say thank you, sir.
I like the strength of the birch plywood bulkheads.
If I keep the birch ply bulkheads, the remaining parts that would be printed are basswood and weigh 1/8 of an ounce.
The weight savings may not be worth issues trying to epoxy the plastic to wood.

But I do like the idea of an all plastic sled.
 

FjStix

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I recently started pursuing the 3D printed option. This is for a 98mm tube and it is the first iteration. It has to undergo a lot of testing still. I plan on performing a sustained stress test (Positive Pull test) on it tonight. Since this photo, I did epoxy coat the sled and the eyelets in. Like I said there are still several hurdles to overcome with this design and I am sure the next version will be more developed. The assembly will be installed with screws through tubes most likely.

If it doesn't survive the stress test, I plan on adding a threaded rod to strengthen it.

At this point, I am not sure I see a benefit of this over wood construction other than the fact that I like to make stuff from scratch.


98mm AV Bay Prototype.jpg
 

AtomicStorm

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Just an idea,why not try to print a half circle where the i bolt is to tie the shock cord to? Do you have anything holding the green and yellow parts together, like a treaded rod?
 

FjStix

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Just an idea,why not try to print a half circle where the i bolt is to tie the shock cord to? Do you have anything holding the green and yellow parts together, like a treaded rod?
There are posts on both sides that go into the top and bottom plates. The I-Bolts thread through and into the center of the sled with some epoxy to bind it all together. The threaded rods are likely going to be added for good measure but I want to see how much force I can pull as is.

I considered printing the eyelet for the shock cord but printed plastics can be brittle and that is a vital part that cannot fail.

AV Bay V1 Top view.png
 

Jowayen

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...I considered printing the eyelet for the shock cord but printed plastics can be brittle and that is a vital part that cannot fail.
Aren't your eyebolts epoxied into the brittle 3D printed plastic?
You may be able to hang weights and get this to hold up to a certain point, but a shock load will snatch the eyebolts and epoxy right out.

A test for this would be to hang one eyebolt from something, then drop a weight tied to the other end.
Force=mass * acceleration so the heavier the weight, and the higher you drop it, the more force you'll have to stress the system.

I'd be very curious to the size of the weight and height you drop it from to get it to break.
 

Mike Haberer

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Looking to find a lightweight, durable removable dual deployment electronics bay for a bt60 vapor. I was wondering what would be the lightest and most durable ebay kit. I like the smt designs bt60 kit, so maybe something like that.
I am very likely going to standardize my AV-Bay designs around SMT Designs offerings. I already have one for Miss Riley (3"). One AV-Bay for each sized BT, transferrable between rockets. Common wiring, common altimeters, common switches, common batteries. A standard design allows for cannibilization of parts if something borks to keep you flying on the field, the same prep steps for each flight and less chance for human error, which is a big factor in a lot of the failures in complex builds.

I've asked Steve Thatcher last week for the base weights of each size AV-Bay he offers (no weights on the web site) so I can include the exact specs in my designs as I have some very weight sensitive designs in the hopper. He said it would it takes a few days to pull together. I'll share on TRF once I get them.
 

AtomicStorm

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I was looking at the different materials and designs and whatever material you decide to use, i believe you need atleast 1 if not 2 threaded rods connecting the bulk heads, bonus points if you can connect your shock cord directly to the threaded rod. Im working on a bt-60 sized 29mm dual deploy wayyyy upgraded estes vapor and im trying to make everything really light. Thought about using some carbon fiber rod i got from lowes, i believe it is 3/16. Just need to find the right fittings and adhesive to make it strong enough to be able to hold the shock, which for this project shouldn't be too much.
 

FjStix

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Aren't your eyebolts epoxied into the brittle 3D printed plastic?
You may be able to hang weights and get this to hold up to a certain point, but a shock load will snatch the eyebolts and epoxy right out.

A test for this would be to hang one eyebolt from something, then drop a weight tied to the other end.
Force=mass * acceleration so the heavier the weight, and the higher you drop it, the more force you'll have to stress the system.

I'd be very curious to the size of the weight and height you drop it from to get it to break.

Yes, It is not capable of much in this form. It may have been super early to post this. The design has changed so much already. This was more of a pathfinder. I will post an update once I complete the design of V2. Steel rods are mandatory and possibly a threaded insert or continuous tube in the center for the eye-bolts.

I just started learning how to model in 3D, so bear with me. This would be a sturdy piece if it was milled out of aluminum but that defeats the purpose of keeping things cheap.


98mm AV Bay V2 Front.JPG
98mm AV Bay V2 Back.JPG
 

MikeyDSlagle

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I have a design that can fit a Quantum and 2S LiPo along with a Missileworks screw switch but you want need it for a Quantum. It also has holes to mount a few other boards as well. Uses two #8 rods with your plates and eyes. I could maybe lighten a bit, especially if you don't want RRC2+
received_453784669100496.jpeg
received_164796595476982.jpeg



You don't need rod at all. Use Kevlar through the bay, epoxied to the coupler and a loop on each end. Machine screws to hold it together, no stress on the end caps/plates at all.

I'm sure I could come up with a rodless design if you just have to have one. I've done custom work for several other folks.

PM (conversation) me if you're interested.
 

AtomicStorm

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I have seen a few people print out 3d parts and then wrap them in carbon fiber or fiberglass for extra support. Maybe that would be a option for a design like fjstix has. Also if you tie in a section of elastic or bungee material to your kevlar shock cord, it would greatly reduce the shock on the av bay, so you wouldn't have to add a bunch of weight over strengthening the bay.
 
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