3D printed reducer in a Camroc Carrier build - vcp

Aware that I was trying to work out the best sort of balsa transition to use for both a Camroc Carrier build as well as a Camroc clone (to also be flown on the Camroc Carrier, forum member vcp very generously offered to send a couple of 3D-printed reducers for me to check out. The package turned out to also include some vintage Carrier parts - ridiculously generous, and such a great addition to my project. Thank you again vcp.

Anyway, I'll post some pictures of the various reducers. I asked for the reducers to be tapered like the Camroc (which I don't possess) is, a little more than 0.5".

From left to right are the 2 3D printed Camroc reducers, then one 3D printed to match the vintage Carrier balsa, the Carrier balsa, and finally the Semroc 0.5" 5060 reducer.



Here is a close up of the 2 Camroc-spec versions:



The Carrier-spec 3D and original side by side:



And finally the Semroc reducer next to the original:



I've also included pics of the 3D's fitting into my standard modern Camroc Carrier tubes. The clear payload is from Estes, available in the variety pack they still sell. The BT-50 tube is from Semroc, and what I have used for both my Carrier and Delta clones.



The fit (and length/taper) of the reducer very critical for Carrier construction, since the paper fairing construction has to work with both the Camroc and the standard clear payload (on reducer), ideally.

The 3D reducers seem to work very well. The fit in both the BT60 and BT50 is really excellent. Snug but not too tight. That the first 2 3Ds are so close to identical speaks well for the reproducibility of the process.

I've not yet tried to sand or paint the 3D printed reducers, so I can't comment on that. The surface though looks very good and I imagine I can get it to look rather like the plastic of the Camroc, if I try.

I hope that vcp will chime in with further details. And thanks for another great forum pay forward - you've really taken my Camroc Carrier / Delta project up a notch in a big way, particularly since the balsa versions, vintage or Semroc, really are no longer available.

Nice Work!

I can't wait to see your finished project.

Jim

What an excellent introduction to how I've spent my beautiful Saturday: In a cave, working on transitions...



The first is a Saturn 1B upper fairing, in Dr. Zooch scale, with a socket printed in for the extra weight. I added in the fairing hinge point details, and they actually don't look too bad. The weight and balance came out very good - this could be certainly be used on a Dr. Zooch model.

The second pic is just a collection of some assorted transition tests, and the third hints at what I'll have soon in my Etsy store: Any Transition You Want.

Al's close pictures of the printed transitions make them look pretty bad... until you look at the balsa, and they look pretty bad too, that close up. And that's what I've always said about printed items: Raw prints will take a moderate amount of finishing work, about the same as a balsa part.

Gary

Hah, Gary, that's just my poor photography and unflattering lighting. I think the surfaces look quite good. Any advice on sanding, filling, painting? Thanks!

So what the heck. I went ahead and made it live.

Any Transition You Want (within certain limits, heh): https://www.etsy.com/listing/178152385/any-transition-custom-conical

Just solid transitions at the moment, I'll add other versions later. The pricing is tentative and most likely too low, but 'twill do for now. Currently I can print up to 5" diameter and 6" total length.

The other versions:


I've done some tests of the socketed versions, and I've found it possible to get a very nice edge between the transition and socketed tube. Advantages of a socket are that it lowers the weight and provides a greater internal volume in the socketed tube. The trick here is to get the CAD software totally parametric so I only have to plug in numbers; that's gonna take another week or two.

Gary

Heck, unflattering lighting is what I want - I don't want anyone harboring illusions that prints will be just a plug and go situation. They will require finishing work.

The biggest difference between plastic/balsa is that you will probably want to start out with some more aggressive sanding; 150 or maybe 90 grit. This will significantly reduce finishing time. You're not going to accidentally gouge it out like you might with balsa. A progression of finer grits will get it as smooth as you want. If fills are required, I've used Squadron body putty. Then you should be able to finish just like anything else, primer, some final sanding and finish coat(s).

The other possibility is acetone vapor finishing, which is a shortcut to a highly gloss finish. There are plenty of links online that describe the method(s), but it's really easy to ruin the part; it requires some experimentation to get the technique right. I've given it a quick try, but not on model rocket parts; I will do some more testing in the next few months. As always, use proper precautions working with acetone.

Gary

vcp said:

Heck, unflattering lighting is what I want - I don't want anyone harboring illusions that prints will be just a plug and go situation. They will require finishing work.

The biggest difference between plastic/balsa is that you will probably want to start out with some more aggressive sanding; 150 or maybe 90 grit. This will significantly reduce finishing time. You're not going to accidentally gouge it out like you might with balsa. A progression of finer grits will get it as smooth as you want. If fills are required, I've used Squadron body putty. Then you should be able to finish just like anything else, primer, some final sanding and finish coat(s).

The other possibility is acetone vapor finishing, which is a shortcut to a highly gloss finish. There are plenty of links online that describe the method(s), but it's really easy to ruin the part; it requires some experimentation to get the technique right. I've given it a quick try, but not on model rocket parts; I will do some more testing in the next few months. As always, use proper precautions working with acetone.

Gary

Click to expand...

The best idea I can think of is to have a before/after image. This is the raw part (as in what you get in the mail), and this is what you can pull off after sanding with XXX, YYY, and ZZZ grits of sandpaper then priming and painting.

Gary,
Those prices look very inviting. Is it too soon to ask about nosecones, e.g. Cineroc, Camroc, Astrocam? Much harder to define the shape with a few numbers, I realize.

I can currently do just about any nose cone up to 6" long, and I have done longer by segmentation. On larger cones I also have a very neat system to bolt on the shoulder, which gives access to the interior and allows 6" lengths not including the shoulder. So "Any Cone" will happen eventually, I just don't want to promise too much too soon. There are two factors: 1) While I have the code to do any regular shape, I still need to parameterize that code so it is plug and play, without too much CAD work required for each new cone - having to spend even an hour/cone would make the job untenable in a hurry. And, B), I only have one printer. If it breaks, getting repair parts could take weeks, and that doesn't make for a good service model. As it is, I've been putting off a major printer upgrade, because it would have the printer down for a week or more. I do have two printers on order, both Kickstarter projects, but they are several months away. I've also got parts on order to build another, but that's probably at least a couple of months away too.

Tramper Al said:

Gary,
Those prices look very inviting. Is it too soon to ask about nosecones, e.g. Cineroc, Camroc, Astrocam? Much harder to define the shape with a few numbers, I realize.

Click to expand...

I have parts for a cineroc clone in the works.

Landru said:

I have parts for a cineroc clone in the works.

Click to expand...

Excellent. Please count me as a customer.

Great work Gary, and a great service to the rocketry community. What I was imagining as I read this thread is that in a few years we'll probably be treating 3D printers parts as being very available, and this type of thread will be viewed as nostalgic 'history'.