Scratch Carbon Airframe with Soller Composites Sleeves

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
So I am looking the get started with making my own airframes, and the current plan is to make some 54mm carbon pieces from the Soller Composites Carbon sleeves to match Wildman airframe dimensions, with either a paper or fiberglass coupler as a mandrel.

So the target would be OD 2.242", ID 2.152" for a wall thickness of 0.045". It looks like two medium sleeves and a light sleeve will get me pretty close (0.047), but I was wondering if anyone had any guidance in terms of sleeve sizing, how much overhang for stretching and securing, and using the Soller shrink tube.

I've seen plenty of videos on using the sleeves to glass paper tubes, but couldn't find a lot on using them to make a standalone airframe.

Thanks
 

robopup

Well-Known Member
Joined
Oct 7, 2021
Messages
62
Reaction score
108
I use sleeves for my nosecones and have been really happy with them. I do not use sleeves for tubing because the fiber orientations aren't great: you want fibers on the tubes going 0/90deg to the axis of the tube, not ~45deg. Accordingly, I use a 0/90 woven fabric (also purchased from Soller). And personally, I find it's actually easier to roll a tube with woven fabric than to apply several sleeve layers.
 

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
That's a good point on the orientation. I think I read somewhere that using larger sleeves so that your desired diameter is close to the minimum diameter of the sleeve, the orientation is better. It does look like 5 layers of the 3k twill will get me exactly the 0.045 wall thickness so I might go with that.
 

robopup

Well-Known Member
Joined
Oct 7, 2021
Messages
62
Reaction score
108
That's a good point on the orientation. I think I read somewhere that using larger sleeves so that your desired diameter is close to the minimum diameter of the sleeve, the orientation is better. It does look like 5 layers of the 3k twill will get me exactly the 0.045 wall thickness so I might go with that.
Sleeve sizing - yes, that's possible. You have to be a little careful though, you're eventually going to hit a "locking" angle where the weave no longer shears. I suppose if you stay just above the recommended min size you'd probably be okay. But you're still left with a laminate which has no 90's (again, good for the loads these see) and non optimal axial fibers (because they're still going to be ~10 or 20 deg or something).

3k CF fabric is what I use - I actually just restocked on this stuff: https://sollercompositesllc.com/product/3k-im7-carbon-plain-weave-sold-by-the-running-yard/ I prefer plain weave over twill because it doesn't shear as much when it's being manipulated. It looks like you're trying to hit a specific OD, but for reference I usually use 3 wraps (~0.03") of the 3k plain weave fabric on 54mm tubes. They're very stiff and strong and I've hit them pretty hard.

As for actually making the tubes, there are a lot of guides. Tony Alcocer and Jim Jarvis both have excellent write ups (I don't have either on hand, but if you google you should be able to find). Here's a brief overview of my process, which is stolen mostly from Tony: https://www.rocketryforum.com/threads/75mm-composite-minimum-diameter-build.173626/post-2298331
 

kenstarr

Well-Known Member
TRF Supporter
Joined
Jan 19, 2011
Messages
1,403
Reaction score
511
Location
Cache County Utah
I just did a tube using soller composites sleeve. I've done several in the past. I used blue tube 54mm coupler for the mandrel. It required a couple wraps of butcher paper to get the appropriate diameter. I used parchment paper as the release over the mandrel and these shrink tubes
for compression because I found the clear shrink tube from soller to be completely unacceptable

I used the carbon/kevlar inside and straight kevlar on the outside... Mainly because I wanted a kevlar looking tube. I think there is a layer of carbon fiber between the two. Can't remember now. 20221114_194919.jpg
I know you can get uni sleeves so the fibers are all oriented along the long axis. Might be a good idea to use that in conjunction with a normal sleeve if you are really going to stress it.
 
Last edited:

rharshberger

Well-Known Member
Joined
Oct 13, 2014
Messages
11,985
Reaction score
3,805
Location
Pasco, WA
Use Blue Tube or Fiberglass coupler stock as mandrels, cardboard is too flexible and may require destroying the mandrel to get it out.
 

REK

Sponsor
TRF Sponsor
TRF Supporter
Joined
Feb 21, 2012
Messages
3,092
Reaction score
109
Location
El Paso, Texas
I just did a tube using soller composites sleeve. I've done several in the past. I used blue tube 54mm coupler for the mandrel. It required a couple wraps of butcher paper to get the appropriate diameter. I used parchment paper as the release over the mandrel and these shrink tubes
for compression because I found the clear shrink tube from soller to be completely unacceptable

I used the carbon/kevlar inside and straight kevlar on the outside... Mainly because I wanted a kevlar looking tube. I think there is a layer of carbon fiber between the two. Can't remember now. View attachment 546299
I know you can get uni sleeves so the fibers are all oriented along the long axis. Might be a good idea to use that in conjunction with a normal sleeve if you are really going to stress it.
Interesting shrink tubing, how easy would you say it was to remove it from the cured tube?
 

kenstarr

Well-Known Member
TRF Supporter
Joined
Jan 19, 2011
Messages
1,403
Reaction score
511
Location
Cache County Utah
Interesting shrink tubing, how easy would you say it was to remove it from the cured tube?
It was actually really easy to remove. I lightly scored down the length in 3 areas and peeled it off like a banana. I had made a prior tube using the soller composites shrink sleeve and was sorely disappointed with the results... Nevermind the finished tube was undersized to fit a 54mm motor.
 

REK

Sponsor
TRF Sponsor
TRF Supporter
Joined
Feb 21, 2012
Messages
3,092
Reaction score
109
Location
El Paso, Texas
It was actually really easy to remove. I lightly scored down the length in 3 areas and peeled it off like a banana. I had made a prior tube using the soller composites shrink sleeve and was sorely disappointed with the results... Nevermind the finished tube was undersized to fit a 54mm motor.
I was curious how this would work with prepregs. I’ll have to order one and see how it turns out. I tried Dunestones shrink tubing, but it bonded to the tube. It was very similar to mylar. This shrink tubing is different material so I am eager to see how it will work out. Would finally be awesome to have tubes with very little or no sanding at all.

Thank you
 

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
Thanks for the heads up on the Soller shrink tube, that was definitely going to be my choice. I love the look of the kevlar tube, we're you able to get a decent surface finish on it? I know kevlar can be a bear to sand.
 

JimJarvis50

Well-Known Member
Joined
Jan 17, 2009
Messages
2,785
Reaction score
1,328
I have one tube that I covered with a sock. It didn't turn out well because I tried the Soller shrink tube, which was a disaster. I never tried to make a tube out of just the sock materials. The main reason for this is that adjusting the sock to the diameter of the mandrel will open up the weave to some extent. I believe the result of this would be a tube with a high weight ratio of epoxy, which seems like it would defeat the purpose of using carbon. The use of shrink tubing doesn't seem to fix this, as I have never seen an example where large quantities of epoxy are squeezed out of the ends of the tube. Please correct me if I am in error regarding these issues. If there is a good process that avoids these issues, I'd like to know about it.

The method I use to make tubes is described in these two articles. Looks like it's been a while since I last posted the links.

https://www.raketenmodellbau.org/repository/archive/167792?view=true (Part 1)

https://www.raketenmodellbau.org/repository/archive/167793?view=true (Part 2)

I still make tubes in much the same was as described in the articles, but I do two things differently that make the process much easier. First, after applying the peel ply and attempting to completely wet it out, I use the tip of a chip brush to remove the air trapped under the peel ply. I just tap the entire surface of the tube with the tip of the brush. This works like magic and removes nearly all of the pin holes in the finished tube. Second, instead of endless sanding and wet sanding, I generally just sand down to reasonably smooth and then wipe on one or two coats of epoxy, removing most of the epoxy on each coat until the tube feels nearly dry. This process gives the tube a little shine, but with 10% of the work of the fully sanded tube.

Jim
 

REK

Sponsor
TRF Sponsor
TRF Supporter
Joined
Feb 21, 2012
Messages
3,092
Reaction score
109
Location
El Paso, Texas
Please correct me if I am in error regarding these issues. If there is a good process that avoids these issues, I'd like to know about it.
I’m experimenting on trying to get a decent result, it all depends on the quality of the shrink tubing to be able to compress enough to squeeze the excess resin. The one I tried from Dunestone applied a good amount to a prepreg layer, however it bonded to it, which I really don’t want that.
 

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
Thanks for the links! I've seen countless references to the "Jim Jarvis Technique®" but never seen the original articles. Any chance of using the sleeves around a nosecone plug and vacuum bagging? I would think that the diameter toward the tip would push the limit of the sleeve minimum diameter.
 

JimJarvis50

Well-Known Member
Joined
Jan 17, 2009
Messages
2,785
Reaction score
1,328
Thanks for the links! I've seen countless references to the "Jim Jarvis Technique®" but never seen the original articles. Any chance of using the sleeves around a nosecone plug and vacuum bagging? I would think that the diameter toward the tip would push the limit of the sleeve minimum diameter.
You're welcome. I should make an addendum of the things I would now do differently.

Jim
 

kenstarr

Well-Known Member
TRF Supporter
Joined
Jan 19, 2011
Messages
1,403
Reaction score
511
Location
Cache County Utah
Here's the second tube I just barely made. I did carbon fiber, kevlar, and fiberglass on the OUTSIDE layer. Previous tube had kevlar on the outside... Not that I'm planning on sanding it. Note the "peeling banana" to remove the shrink. Pretty easy to remove
20221126_185325.jpg
 

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
Looks good! Do you know what your wall thickness ended up being? I'm leaning back toward the sleeves since it's tough to find kevlar and s-glass ply in widths wider than ~27in.
 

REK

Sponsor
TRF Sponsor
TRF Supporter
Joined
Feb 21, 2012
Messages
3,092
Reaction score
109
Location
El Paso, Texas
Looks good! Do you know what your wall thickness ended up being? I'm leaning back toward the sleeves since it's tough to find kevlar and s-glass ply in widths wider than ~27in.
Here you go

 

kenstarr

Well-Known Member
TRF Supporter
Joined
Jan 19, 2011
Messages
1,403
Reaction score
511
Location
Cache County Utah
I really feel like the sleeves are a novelty if you are just using sleeves and removing the mandrel because it's a MAJOR PAIN to get the release layer the right thickness and I'm pretty sure wrapping with a fabric is much stronger but I'm no engineer. I built a 38mm min diameter rocket years ago using 2 layers and launched on an I1299 with no issues. I'm envisioning these tubes for a rocket with an L1000 giving a push.
Wall thickness appears to be about .07" on average. Oh, here's a tube where I just used sleeve for reinforcing. One layer of thick fiberglass. 10 diameter sleeve maybe? I think that's where the sleeve really shines
Ken
 

Attachments

  • 16695706812718162589567486627690.jpg
    16695706812718162589567486627690.jpg
    1.4 MB · Views: 0

pyrrxa

Member
Joined
Nov 23, 2021
Messages
13
Reaction score
0
The sleeves definitely seem to shine as a relatively light reinforcement. I'm thinking of maybe doing a reinforced cardboard H999/I1299 optimized rocket. Main plan is a 54mm bird built around the Loki 54/4000 case and then adapted down for local flying, so trying to plan out structural components for that.
 
Top