[outback97]

I read through the thread and unless I missed it I didn’t see what the ends of the strut pieces are dipped/coated in to cover them?

Thanks for the question. I thought I had listed them, but it looks like I forgot to include that. They're just "caps for strut channel" and can be found at McMaster Carr, and I'm sure other suppliers too.

https://www.mcmaster.com/cadinlnord/3312t11

I've added this to the first post as well.

 

[Rogue]

Here is another clamp option... for those who hate money LOL. I have 4 of these but I'm pretty sure I did not pay that much for them.

https://www.amazon.com/Power-Tank-ABC-2465-Billet-Aluminium/dp/B002KCE6H4

 

[outback97]

Here is another clamp option... for those who hate money LOL. I have 4 of these but I'm pretty sure I did not pay that much for them.

https://www.amazon.com/Power-Tank-ABC-2465-Billet-Aluminium/dp/B002KCE6H4

Thanks for posting those, hadn't seen them before. They look nice, and would be a bit lower profile compared to the ones I used. They are a bit expensive though!

I wonder how strong they are compared to a ubolt that wraps around the bar?

 

[timmytoast]

Another question for you: any chance you measured or can measure the length of 3/4” PVC needed for the DIY rotopax mounts?

 

[outback97]

Another question for you: any chance you measured or can measure the length of 3/4” PVC needed for the DIY rotopax mounts?

Hey, sorry, I just saw this. I can definitely do that. It's super easy to cut PVC so when I was putting this together I just started by eye and then took off a little more until it was the right length. The length needed will also depend on the thickness of the other hardware you're using.

I've been thinking about an improvement to the PVC setup, and that would be to 3D print something in the shape of the Rotopax mounts.

Basically just this type of shape with holes through it that would replace the two PVC rods. I think it'd be a bit more stable being a solid block. You'd thread the rods into two channel nuts and then slip this over it.

I have no experience creating a 3D print file, though I have had the library print one for me. Can anyone suggest where I'd start if I wanted to create something like the above? @29erClan @caain

 

[29erClan]

...
Basically just this type of shape with holes through it that would replace the two PVC rods. I think it'd be a bit more stable being a solid block. You'd thread the rods into two channel nuts and then slip this over it.

I have no experience creating a 3D print file, though I have had the library print one for me. Can anyone suggest where I'd start if I wanted to create something like the above? @29erClan @caain

Start here: https://www.thenewx.org/forum/89-free-items/272776-free-some-my-3d-models.html

You ought to be able to import those IGS files into anything and modify as you wish. The 3d printed plastic isn't always very strong but if you're bolting through it should be fine - it's just being a spacer like the PVC pipe is. After you've got your changes worked out you export that 3d file as STL format for printing. onShape makes it pretty easy and is free.

 

[caain]

Hey, sorry, I just saw this. I can definitely do that. It's super easy to cut PVC so when I was putting this together I just started by eye and then took off a little more until it was the right length. The length needed will also depend on the thickness of the other hardware you're using.



I've been thinking about an improvement to the PVC setup, and that would be to 3D print something in the shape of the Rotopax mounts.

Basically just this type of shape with holes through it that would replace the two PVC rods. I think it'd be a bit more stable being a solid block. You'd thread the rods into two channel nuts and then slip this over it.



I have no experience creating a 3D print file, though I have had the library print one for me. Can anyone suggest where I'd start if I wanted to create something like the above? @29erClan @caain

I need to get the dust off my printer and finish 29erClan's wobble extension handle yet (it's been a crazy month), but I could try making a few prototype prints of whatever it is you come up with. I have the same Rotopax and ended up spending the money for the DLX mounts since I was in a hurry to get it mounted before a trip. I should have gone your route and done them myself!

I made a few brackets to hold a light bar on my roof rack and they came out pretty sturdy. But I used a UV-resistant plastic and printed them at a really high infill, so they're pretty dense. Took 8 hours to print each one, but they haven't failed me yet. I think there are some photos of them in my build thread.

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[29erClan]

Welp, I'm a dummy. It's already been imported as part of the roof rack project...

If you are planning to use 1/4" bolts you may not need to make any changes at all. STL attached in the ZIP.

EDIT: new STL with 3/8" (0.400") bolt clearance holes attached.

 

[outback97]

I need to get the dust off my printer and finish 29erClan's wobble extension handle yet (it's been a crazy month), but I could try making a few prototype prints of whatever it is you come up with. I have the same Rotopax and ended up spending the money for the DLX mounts since I was in a hurry to get it mounted before a trip. I should have gone your route and done them myself!

I made a few brackets to hold a light bar on my roof rack and they came out pretty sturdy. But I used a UV-resistant plastic and printed them at a really high infill, so they're pretty dense. Took 8 hours to print each one, but they haven't failed me yet. I think there are some photos of them in my build thread.

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Will check out the build thread. Is the infill something that is specified in the file? Or a printer setting? I need to do some googling.

Welp, I'm a dummy. It's already been imported as part of the roof rack project...


If you are planning to use 1/4" bolts you may not need to make any changes at all. STL attached in the ZIP.

I mostly use 3/8" threaded rod or bolts for my DIY roof rack attachment stuff, but I have some 1/4" spring nuts too and I'm sure 1/4" would be plenty strong. I would probably need to come up with a spacer or plate to go underneath the mount.

You guys are awesome, thanks!

I found this when googling for Rotopax and 3D printed stuff:
https://www.thingiverse.com/thing:3122299

The caps are hard to get off when tightened enough to seal. This thing would be quite handy, although right now I just use a channel lock pliers which works well enough.

 

[caain]

Will check out the build thread. Is the infill something that is specified in the file? Or a printer setting? I need to do some googling.

It's basically a printer setting. The 3D model file usually comes in an STL format. From there, it's loaded into a Slicer that converts the model to a series of instructions set up for a particular printer (speed, temperature, texture, infill, etc.). I usually do prototypes at around 10% infill. I think the mounting brackets I made were 70-80 (overkill).

I found this when googling for Rotopax and 3D printed stuff:

https://www.thingiverse.com/thing:3122299



The caps are hard to get off when tightened enough to seal. This thing would be quite handy, although right now I just use a channel lock pliers which works well enough.

I like this! Once I get running with the printer again I'll see about running a few off. I've been trying to use up some awful filament I bought on sale, but I think it's going in the garbage and I'm ordering new stuff.

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[outback97]

Another question for you: any chance you measured or can measure the length of 3/4” PVC needed for the DIY rotopax mounts?

Looks like 2.25”.

 

[caain]

I found this when googling for Rotopax and 3D printed stuff:
https://www.thingiverse.com/thing:3122299

The caps are hard to get off when tightened enough to seal. This thing would be quite handy, although right now I just use a channel lock pliers which works well enough.

I shortened the handle a bit and ran one off with what I have on hand. It didn't come out too pretty, but it definitely works. I'll get one printed with better filament next week and send it out to you. I think it'll survive in a padded envelope.

 

[outback97]

Wow, that’s cool @caain!

 

[caain]

new STL with 3/8" (0.400") bolt clearance holes attached.

I've got a few (rough) estimates for the 3/8" hole version:

• 25% infill: ~3.05 hours, ~48 grams, ~19.2 meters of filament ($0.46)
• 50% infill: ~3.75 hours, ~66 grams, ~26.5 meters of filament ($0.64)
• 75% infill: ~4.25 hours, ~82 grams, ~32.7 meters of filament ($0.78)
• 99% infill: ~4.75 hours, ~96 grams, ~38.5 meters of filament ($0.92)

I list the last as 99% because desktop printers will never do fully 100% solid prints. I usually print really slow, so someone with a better machine will likely be able to print these more quickly than me. The prices are just to illustrate how cheap 3D printing materials can be (this is for PETG @~$24/kg). Other filaments are cheaper, and some are way more expensive (carbon fiber, metal filled, polycarbonate, etc.). @29erClan, do you mind if I ask what the library charged for printing the wobble handle tool in PLA? It looks like they have a very nice machine!

I'm not sure what the best option would be for infill. @outback97, do you know about how much weight will be on these? I know that might be hard to answer. PETG has some give/flex to it, while PLA can be a bit brittle and is biodegradable. Something like ABS or ASA might work well too, but I don't have any experience with those.

 

[29erClan]

29erClan, do you mind if I ask what the library charged for printing the wobble handle tool in PLA? It looks like they have a very nice machine!

The library wasn't technically involved in printing the handle. A friend and I pooled up and bought a mini delta. Our intention is to learn to run it well and be the back end service for the library. The librarian will setup the presentations and public side stuff. She doesn't have any idea how to do the modeling or printing, but she seems interested in this sort of volunteer partnership. We can afford to donate a spool every month, and that may be plenty to keep the kids busy. If the project works she might write it all up and share it with ALA so other small libraries that don't have the space, staff, or time can still offer 3d printing. It's a fun side project.

Anyway, I think the handles cost like $0.25 or so for material. I forget what the slicer said at the end. I picked fine mode with 0.1mm layers, and each handle was around 4 hours to print. I pressed the extension bars in with a hammer. They were fairly tough. Maybe 20% infill setting.

And for what it's worth I've never had to tighten my rotopax cap very hard at all. The rubber gasket is great. The key is to scrape any flash off the mating surface. I used a regular utility razor.

Just scrape, don't cut, or you could make it leak worse.

 

[caain]

The library wasn't technically involved in printing the handle. A friend and I pooled up and bought a mini delta. Our intention is to learn to run it well and be the back end service for the library. The librarian will setup the presentations and public side stuff. She doesn't have any idea how to do the modeling or printing, but she seems interested in this sort of volunteer partnership. We can afford to donate a spool every month, and that may be plenty to keep the kids busy. If the project works she might write it all up and share it with ALA so other small libraries that don't have the space, staff, or time can still offer 3d printing. It's a fun side project.

Anyway, I think the handles cost like $0.25 or so for material. I forget what the slicer said at the end. I picked fine mode with 0.1mm layers, and each handle was around 4 hours to print. I pressed the extension bars in with a hammer. They were fairly tough. Maybe 20% infill setting.

And for what it's worth I've never had to tighten my rotopax cap very hard at all. The rubber gasket is great. The key is to scrape any flash off the mating surface. I used a regular utility razor.

Just scrape, don't cut, or you could make it leak worse.

Congrats on the delta! I've always liked those printers. I'm impressed with the print quality, and that sounds like a really great project you're working on.

I'll scrape some of the flash off the cap and see how it fits. I'm always worried about gas leaks being as it's usually mounted on the roof, but I don't use it that often right now anyway. I boxed up the bad filament and ran off another wrench with some clear PETG I have while I'm waiting for new stock. It's almost impossible to get anything to come out clear with how FFF printers work, but it makes a kind of cool 'frosted' look where you can see some of the internal honeycomb structure (or whatever infill pattern you select):

@outback97, if you're okay with the clear filament, I can send you out one of these. They are the full-size handle version. Just shoot me your address in a PM if you want one.

 

[outback97]

I'm not sure what the best option would be for infill. @outback97, do you know about how much weight will be on these? I know that might be hard to answer. PETG has some give/flex to it, while PLA can be a bit brittle and is biodegradable. Something like ABS or ASA might work well too, but I don't have any experience with those.

Thanks! It's hard to say. There wouldn't be a lot of weight on them because the Rotopax are laying down on my crossbars. There would be some force on them as I drive around and the fuel can wants to slide and move. Really they're more like spacers to keep the 3/8" threaded rod in place, the role currently being filled by the short length of PVC pipe.

The clamping from the plate, the rod and the strut crossbar is doing most of the important work here. Even if the spacer totally evaporated while in use, the fuel cans wouldn't go flying off. They would just move around a lot more, and possibly the rod could loosen from the spring nuts.

...
And for what it's worth I've never had to tighten my rotopax cap very hard at all. The rubber gasket is great. The key is to scrape any flash off the mating surface. I used a regular utility razor.

Just scrape, don't cut, or you could make it leak worse.

Thanks for the idea, I may have to try that. Although when I'm using mine, we tend to be traveling through a lot of elevation and temperature changes, so I still think I'd have to crank them down pretty tight. I have never used a tool to tighten them, it's just when I tighten them down by hand enough to not leak when laying flat, I often have trouble opening them by hand when it's time to use them.

This afternoon I picked up my dashboard radio mounts from the library, and I'm pretty disappointed. Not in the file, it's perfect, and the same library printed them just fine a couple years ago. They printed them laying down flat, despite what I thought were very clear instructions about how they should be printed. And, it took a month to get them done. I may try another library branch next time... I need to find the right people there to speak to who would even understand infill and different plastics.

 

[caain]

Thanks! It's hard to say. There wouldn't be a lot of weight on them because the Rotopax are laying down on my crossbars. There would be some force on them as I drive around and the fuel can wants to slide and move. Really they're more like spacers to keep the 3/8" threaded rod in place, the role currently being filled by the short length of PVC pipe.

I'd think that 50% infill would be more than adequate for this sort of thing, and might even be a bit of overkill. Would it be helpful to have the bolt holes large enough that the bolt passes through easily, or reduced in size slightly so the bolts would be threaded through? Printing threads this small won't work well with a desktop printer, but if you make the hole a bit 'too small', you can use the bolt as a tap and cut threads into the plastic the first time through.

This afternoon I picked up my dashboard radio mounts from the library, and I'm pretty disappointed. Not in the file, it's perfect, and the same library printed them just fine a couple years ago. They printed them laying down flat, despite what I thought were very clear instructions about how they should be printed. And, it took a month to get them done. I may try another library branch next time... I need to find the right people there to speak to who would even understand infill and different plastics.

Can I ask what about them was disappointing? Surface finish, color, resolution, etc.? Just curious.


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[outback97]

I'd think that 50% infill would be more than adequate for this sort of thing, and might even be a bit of overkill. Would it be helpful to have the bolt holes large enough that the bolt passes through easily, or reduced in size slightly so the bolts would be threaded through? Printing threads this small won't work well with a desktop printer, but if you make the hole a bit 'too small', you can use the bolt as a tap and cut threads into the plastic the first time through.

Can I ask what about them was disappointing? Surface finish, color, resolution, etc.? Just curious.

Slightly larger holes would work best. This spacer would be slipped over the rods, rather than tightened down with threads. Then the fuel can is dropped over it, then the round plate, then wing nuts tightened

Regarding the poorly printed radio mount, see photos below. It could be as simple as printing from the wrong axis, not sure if there's other factors. The gray is the new one, black is the old correctly printed one. I don't know enough about 3D printing to really describe it, but the pictures should show better than I can tell.

And I very explicitly told them to print from the "bottom" of the mount, not the mounting surface. Even included a photo in my email depicting it. They just didn't pay attention. I'm not mad about it, I didn't pay anything for this, but it's just a lot of time spent.

 

[caain]

Slightly larger holes would work best.



Regarding the poorly printed radio mount, see photos below.

The modified 3/8" Rotopax mount 29erClan made should be perfect as-is then. Sorry to have you explain all that again - never had my coffee this morning.

As for the prints, it looks like a combination of factors. They did print from the wrong axis, and they also used a very large layer size rather than the fine size of your original mount. This can be done to speed up printing considerably, but it makes for jagged prints when there are curves/slopes in the model. It also looks like they printed with supports and did not (or could not) detach them - that's why the relief areas on the back designed for mounting tape are roughly filled in.

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