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thzero

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Building out a sport scale version of the BBX based on Peter Alway's books based on the BT60 tubes. This is doing a fiberglass BT-60 using Mach 1 tubes based dual-deploy that will launch on composite Cesaroni motors, and has a multitude of 3d printed parts as opposed to my D/E powered gap staged BT60 version (https://www.rocketryforum.com/threads/bbx-scratch-builds.163933/).

Starting with a bag of parts...

PXL_20210124_185951711.jpg


Couple of printed parts poking out there.
 

thzero

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Custom printed sled for a GPS and an altimeter. Specifically the cage is for the JollyLogic Altimeter, I usually use the Altimeter 3, and then either a Missileworks or Raven GPS, although I do have a Eggtimer available.

PXL_20210124_225234169.MP.jpg
 

thzero

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And beginning of a printed avbay. Most likely running either a Featherweight or an Eggtimer Quantum (only have an RRC3 which is way too big). Will print custom "sleds" that attach with screws to hold the altimeter and its battery. Kevlar loops will be used instead of an eyebolt.

PXL_20210124_225355546.jpg
 

thzero

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Here is the screen shot of the coupler from the CAD software. Printed out a couple of test pieces to get fit, etc. in PLA.

Capture.PNG


Final parts are all being printed in PETG on a Creality CR-6 SE.
 

thzero

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Got the coupler printed in PETG - takes a lot longer due to the slower print speeds. But came out well, only real issue is that I'd tweaked the model to account for PLA shrinkage and PETG does change as much (required little to no fan in printing). However, its ok because lets me 'customize' the fit. Did built a mechanical ledge into the design to glue in a bulkhead for recovery purposes of the booster.

PXL_20210128_213353426.jpg
 

g.pitts

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Got the coupler printed in PETG - takes a lot longer due to the slower print speeds. But came out well, only real issue is that I'd tweaked the model to account for PLA shrinkage and PETG does change as much (required little to no fan in printing). However, its ok because lets me 'customize' the fit. Did built a mechanical ledge into the design to glue in a bulkhead for recovery purposes of the booster.

View attachment 448350
Not sure if this helps you, but you can keep your model at its current spec, and use Cura's scaling capability to compensate for any dimensional change after printing.
 

Nytrunner

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Great project?

Are you running any sort of reinforcing tube through the throat of that coupler? Bending loads on the neck of that FDM printed part are not comforting
 

thzero

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In this case, not really. It was mostly the internal dimensions, the outside dimensions are fine :)
Not sure if this helps you, but you can keep your model at its current spec, and use Cura's scaling capability to compensate for any dimensional change after printing.
 

thzero

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Yeah, its not. however, all my horizontal print attempts have not panned out at this time. But yes, that is for a sure a concern. Was thinking about running some fiberglass cloth strips inside as re-enforcement. I've done that on a few other 3d printed parts (these were done online, so had less control over how they were printed) that are couplers - it was for an Estes Saturn V; and thus far those have held up ok.

Great project?

Are you running any sort of reinforcing tube through the throat of that coupler? Bending loads on the neck of that FDM printed part are not comforting
 

thzero

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Test print for a booster fin can for the rocket. Will have at least one layer of fiberglass on the fins at least when do the final print. The idea is to have a bit more scale fins, as opposed to flat wood or fiberglass.

PXL_20210326_150510032.jpg
 

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