3D Printing Custom Transistions

[Enocelot]

Hi does anyone here make customized transistions?

I'd be happy to pay a fair price for 3 each:

-Length: 1.5 cm BT50 to BT5
and
- Length: 3 cm BT50 to BT55

transistions.

Cheers!

Eno

 

[Arnie]

Looking for a hollow Bt-20-Bt-50 and a hollow Bt-5-Bt-20 transistions

 

[cwbullet]

I can probably do this but I need more info. Do they need attachment points?

I would not do hollow but I would do 10% infill.

 

[Arnie]

I can probably do this but I need more info. Do they need attachment points?

I would not do hollow but I would do 10% infill.

No attach points needed. I want them hollow ln order for the ejection charge to pass from the narrower body tube to the wider tube.

 

[rocketgeek101]

I would not do hollow but I would do 10% infill.

A hollow transition at this size would be easy to do. Speaking from experience, with a 4mm nozzle and 4 perimeters it would be sufficiently strong.

 

[cwbullet]

No attach points needed. I want them hollow ln order for the ejection charge to pass from the narrower body tube to the wider tube.

Personally, I would not do it that way. I would line it with paper tubing. This will insulate from the hot gasses.

 

[cwbullet]

A hollow transition at this size would be easy to do. Speaking from experience, with a 4mm nozzle and 4 perimeters it would be sufficiently strong.

I Know it is easy to print, but it is easy to damage with hot gasses.

 

[Arsenal78]

I second lining it with a tube. If you glue it in, over time those gases and powder bits will melt the plastic and it will deform. Line it with a tube and then coat the bottom part that faces the ejection with some epoxy.

 

[Enocelot]

Bullet,

I'm not thinking I need attachment points. I am going to join with long couplers.... in fact, my plan was to link the the couplers inside the plastic "skins" to shield the plastic from the ejection gasses. Maybe surround the couplers with some wadding inside the transistions?

If you can do them and they work, I may become a regular customer - at least until I ever muster the testosterone to dabble in 3-D printing myself!

 

[Enocelot]

In fact there may be a product line here....

 

[rocketgeek101]

I Know it is easy to print, but it is easy to damage with hot gasses.

I can only speak from my own experience, but I have found that it really isn't an issue when printed out of a more temperature resistant material like PETG. I have several fully 3D printed rockets made with PETG and even after several flights (with some printed components directly in the line of fire of the ejection charge) they show no signs of damage or deformation from the ejection gasses.

 

[cwbullet]

I can only speak from my own experience, but I have found that it really isn't an issue when printed out of a more temperature resistant material like PETG. I have several fully 3D printed rockets made with PETG and even after several flights (with some printed components directly in the line of fire of the ejection charge) they show no signs of damage or deformation from the ejection gasses.

I have a few fail. I certainly print more than 99% of the forum. Some nose cones and transitions have warped with heat. They also fail with UV exposure.

 

[Arsenal78]

The trick with PETG is getting to actually print right. I tried it a few times but could never get it to stop stringing and coming out rough. I gave up and I use eSUN PLA Pro for the most part. I did get some PLA-F for Christmas which is supposedly a blend of ABS and PLA. I have yet to test it but I am printing out an upscale Art Applewhite Stealth with it to try.

 

[OzHybrid]

I have a few fail. I certainly print more than 99% of the forum. Some nose cones and transitions have warped with heat. They also fail with UV exposure.

I've recently been printing ABS with a 0.6 nozzle printing at 0.65 at 0.2 layer. Massive increase in deposition and strength. With really nice results. And ABS is generally good in the sun. Always had difficulty with PETG. So stopped using it.

 

[manixFan]

All I print with now is PETG. Virtually no stringing or blobs. The key is adjusting the amount of retraction. It’s so much more heat resistant than PLA it’s worth the trouble. PLA is basically unusable in Texas in the summer.

You can also line the passage with just rolled up bond paper. That way you can replace it between launches if need be. I’ve done that in several instances where I needed to protect inner tubes from hot gasses and it works well.


Tony

 

[dr wogz]

to to OP:

Why not just use / make paper transition?

and to it 'traditional': smaller BT in CRs inserted in teh larger BT. then teh transition just covered up teh step..

 

[OzHybrid]

Here's a transition generator SCAD file I just wrote Default values are BT5 to BT50. at 15mm length. All dimensions in millimetres.
Have fun.. Looks like it's about Au$30 for Qty3 from a generic printing house in ABS. plus postage. Or learn to print.....$$
to create a new preset, click the+, put your new name in the box that opens, then change the dimensions. Otherwise you'll overwrite the existing preset, not create a new one.... Increase the facet numberfor the final render to $fn=120 or whatever you're happy with.
Enjoy.....

 

[cwbullet]

That is pretty slick. Is it possible to make it solid as an option?

 

[OzHybrid]

That is pretty slick. Is it possible to make it solid as an option?

A solid has a hole with dimension 0.0 This will throw up a couple of warnings. Ignore them. The short straight sections(you can make them any size you want) are there to give a couple of layers printed at full OD to ensure the transition doesn't print undersized on the OD when sliced. (I did my best to think about the full process. Bores go into transition by 10% before tapering to meet next bore to ensure a sort of consistent wall thickness.)

 

[cwbullet]

A solid has a hole with dimension 0.0 Which will throw up a couple of warnings. Ignore them.

I figured it out. It is quite a neat piece of programming.

 

[OzHybrid]

I'm not drinking beer. That makes it easier. See updated previous post. :0

 

[OzHybrid]

The trick in making it all work is the fudge factors. For simple stuff you can get away with just assembling a block on top of a block. If you want to guarantee it works well, one block needs to be slightly inside the other, by an amount so small it's a nothing, 0.01mm, but inside it. The F and F2(if you need 2x F) are a simple easily added variable that stick it all together. Much easier than typing -0.01 or +0.02 where needed everywhere.

Norm

 

[cwbullet]

Here is a BT50-Bt60 Transition that is hollow:

 

[OzHybrid]

Here is a BT50-Bt60 Transition that is hollow:

Or hAllow in this case. bt50-bt60-hallow-transition-stl.502690/

 

[cwbullet]

Or as I make them with an attachment on both ends:

 

[OzHybrid]

Looks like my transition design. You've learned grasshopper. It's easy enough to drill a hole, but printing a hole does allow for reinforcement by having full walls there. And the advantage of the customiser is that the files are available to all and can be customised. Once you've got your spreadsheet with tube sizes(available elsewhere on the forum), just plug the numbers in. Then you have ALL transitions, if you can print them as an engineering part, not just a pretty piece. It's tricky to get engineering parts from FDM printers.
It takes more work to create a SCAD file. But it only has to be done once and you've got EVERY transition
When I created my fin program, someone said it was too complicated. To create nice fins there are quite a few parameters..... So if you want a nice fin you have to be able to specify a lot of parameters. I created a whole bunch of presets for generic types of fins to get you started. But not enough for some. Hey ho.

What would you prefer as an attachment point? What is the hex hole for? Easier to print as the roof is 60deg angle not a curve? Is this why you want to do it solid? Makes it easier to attach a cord?

I'll add a few things in. Back in a moment. Stay tuned......

 

[cwbullet]

Looks like my transition design. You've learned grasshopper. It's easy enough to drill a hole, but printing a hole does allow for reinforcement by having full walls there. And the advantage of the customiser is that the files are available to all and can be customised. Once you've got your spreadsheet with tube sizes(available elsewhere on the forum), just plug the numbers in. Then you have ALL transitions, if you can print them as an engineering part, not just a pretty piece. It's tricky to get engineering parts from FDM printers.
It takes more work to create a SCAD file. But it only has to be done once and you've got EVERY transition
When I created my fin program, someone said it was too complicated. To create nice fins there are quite a few parameters..... So if you want a nice fin you have to be able to specify a lot of parameters. I created a whole bunch of presets for generic types of fins to get you started. But not enough for some. Hey ho.

What would you prefer as an attachment point? What is the hex hole for? Easier to print as the roof is 60deg angle not a curve? Is this why you want to do it solid? Makes it easier to attach a cord?

I'll add a few things in. Back in a moment. Stay tuned......

The hex hole allows it to print better and the square cutouts allow the cord to avoid contact with the body. I use it for the suck cord attachment.

 

[OzHybrid]

Something like this.

Aerofoiled internal connection bars to allow free flow of ejection gasses and allow hollow transition with connection without crushing.
Hex hole for easier printing. Adjustable hole diameter. Variable slot depth and width, bar shape scalable to go from round to aerofoiled.

 

[Enocelot]

So does someone want to make me 3ea. BT50s to BT5s length 1.5 cm, and BT50s to BT55s length 3cm for $60 bucks plus postage?

I prefer them hollow.

 

[Enocelot]

Gotta admit, this stuff does look kind of cool..... makes me wish I were 30 years younger.....