[29erClan]

... 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.

That's why guys like me and @caain get the big bucks. We do free stuff right! Oh, wait...
:grin:

 

[29erClan]

...Printing threads this small won't work well with a desktop printer,

I don't mean to argue, and this is wandering off topic too, but I'm surprised how well it does work. Earlier today I was making some replacement parts to fix the twist-lock mechanism in a collapsible cane. What you see there is a 1/4-20 thread. Took me a while to figure out how to sweep a helix and look up all the thread sizing dimensions. Pretty cool that it worked so well - now the cane only collapses when you want it to. :thumbup:

 

[caain]

I don't mean to argue, and this is wandering off topic too, but I'm surprised how well it does work. Earlier today I was making some replacement parts to fix the twist-lock mechanism in a collapsible cane. What you see there is a 1/4-20 thread. Took me a while to figure out how to sweep a helix and look up all the thread sizing dimensions. Pretty cool that it worked so well - now the cane only collapses when you want it to. [emoji106]

By all means feel free to prove me wrong anytime! I'm here to learn. And I agree on the off-topic bit - sorry outback!

Sent from my Pixel XL using Tapatalk

 

[timmytoast]

Looks like 2.25”.

Thank you. I'm planning on making a DIY rotopax mount for my Gobi ladder.

 

[caain]

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.

These came out pretty well! I'm excited to see how they work for @outback97. They make my anodized Rotopax mounts look a bit purple..

 

[outback97]

@caain @29erClan those look amazing! Nice work and thank you!

 

[outback97]

I got the 3D printed Rotopax "mounts" (really spacers in my application) from @caain the other day. They look awesome! @29erClan

Here's a "cross section" view of how they mount to the strut channel. They're just slipped over the 3/8" threaded rod.

These should absolutely work to replace the PVC pipe / washers / nuts that I have been using to mount the fuel can. Since I am using them in this way instead of being mounted on a Rotopax base plate, they are a little short. If they were a little taller and had a thicker, flat base the width of the strut channel, it'd be an even better fit.

I'm looking forward to trying them out when it doesn't look like this outside.

 

[caain]

I got the 3D printed Rotopax "mounts" (really spacers in my application) from @caain the other day. They look awesome! @29erClan

These should absolutely work to replace the PVC pipe / washers / nuts that I have been using to mount the fuel can. Since I am using them in this way instead of being mounted on a Rotopax base plate, they are a little short. If they were a little taller and had a thicker, flat base the width of the strut channel, it'd be an even better fit.

I'm very glad they fit! What changes would you make to the design so they'd fit better? I know we talked about removing the center hole. What about making the design a simple oval instead of the 'three lobe' design? They'd fill up the Rotopax hole a bit better and be a little stronger - and maybe take less time to print too, given the simplified design. How much taller would you make them? Making a wider base on the bottom to match the strut channel would be pretty easy too.

I hope it warms up over there soon!

 

[outback97]

I'm very glad they fit! What changes would you make to the design so they'd fit better? I know we talked about removing the center hole. What about making the design a simple oval instead of the 'three lobe' design? They'd fill up the Rotopax hole a bit better and be a little stronger - and maybe take less time to print too, given the simplified design. How much taller would you make them? Making a wider base on the bottom to match the strut channel would be pretty easy too.

I hope it warms up over there soon!

Not sure about the dimensions. I need to take some measurements, but something like shown below, with the yellow the added material. More height, and a wider base. Maybe even matching the gap in the strut channel to "key" it into there? Or would that make it weaker?

I'm not using the center hole, and the lobed design isn't really necessary. So, it could be simplified. I have thought about just using one center bolt, but I do like the redundancy of two bolts per mount... one is none and two is one and all that.

I'll have to get some measurements and see how much taller to go. The cool thing is it will work well as it stands right now. These things came out really nice!

 

[29erClan]

How about incorporating a 4" circle? I think it was 4" when I made the ladder mount thing. Being printed you could even include divots for those 2 bumps. With a round plate having a small chunk of the space shape (like 0.25-0.50") you could use 2. Both sides - base for support, top like a washer for wing nuts.

I hope I'm not too tired to put useful words together trying to describe what I'm seeing. :sleepy2:

 

[caain]

How about incorporating a 4" circle? I think it was 4" when I made the ladder mount thing. Being printed you could even include divots for those 2 bumps. With a round plate having a small chunk of the space shape (like 0.25-0.50") you could use 2. Both sides - base for support, top like a washer for wing nuts.

I hope I'm not too tired to put useful words together trying to describe what I'm seeing. :sleepy2:

I am going to try to visualize this in the morning when I've had coffee.. I just don't have the brain power at the moment! I still haven't learned anything about OnShape (it's on my list), but I did play with a basic design in Sketchup. Just simplifying it, really - removing the lobes/contours, giving it a wider footprint. It looks like a cartoon now. I must learn OnShape..

 

[29erClan]

That's pretty much what I was thinking.

I was hoping to print it scaled up an extra 1.5% or whatever the aluminum casting shrink factor is and use it as a casting pattern. Well, when I get a chance to build a backyard forge...

This version has draft angles matching the 2G plastic can (I don't know about any others) and is about 1mm shy of the center-line so you can apply some clamping force but not too much. You could also chop it off 1/4" or so above the mount disc and use the original spacer. And the bolt holes can be changed or deleted for the cast aluminum version for direct tapping, etc.

EDIT: forgot the file. It's also in the roof rack project under the acc/fuel folder.

 

[outback97]

I am going to try to visualize this in the morning when I've had coffee.. I just don't have the brain power at the moment! I still haven't learned anything about OnShape (it's on my list), but I did play with a basic design in Sketchup. Just simplifying it, really - removing the lobes/contours, giving it a wider footprint. It looks like a cartoon now. I must learn OnShape..

Thanks! Yes, like that, though I don't know how much of a lip there can be on the ends of the long axis, and I don't know how high the lip can be before it gets in the way. This weekend I should be able to take a closer look at it.

That's pretty much what I was thinking.

I was hoping to print it scaled up an extra 1.5% or whatever the aluminum casting shrink factor is and use it as a casting pattern. Well, when I get a chance to build a backyard forge...

This version has draft angles matching the 2G plastic can (I don't know about any others) and is about 1mm shy of the center-line so you can apply some clamping force but not too much. You could also chop it off 1/4" or so above the mount disc and use the original spacer. And the bolt holes can be changed or deleted for the cast aluminum version for direct tapping, etc.

EDIT: forgot the file. It's also in the roof rack project under the acc/fuel folder.

That looks sweet! Dumb question, but to create a cast, would you 3D print it, then create a mold from that (with what?) that you then would cast into?

It *seems* like these clamps should be better at preventing movement of the fuel can when bouncing along rough roads, or cornering at speed. I'm not smart enough to figure out whether that type of design would be a big improvement over my simple spacer and metal disc clamp setup.

These definitely look better than my ham fisted plumbing store hackery!

 

[29erClan]

to create a cast, would you 3D print it, then create a mold from that (with what?) that you then would cast into?

Yes sir, I'd use a shrink-factor scaled-up 3d print as the pattern for a sand mold. Here's a nice youtube series that I'd aspire my backyard foundry to be as nice as:
https://www.youtube.com/playlist?list=PL69F982076354AC97
Or just use a pair of non-scaled plastic ones as-is.

It *seems* like these clamps should be better at preventing movement of the fuel can when bouncing along rough roads,

Well, "seems" is almost as bad a word as "assumes"... In all honesty, if you're laying them down flat on the roof rack all these really do is protect the can from the threaded bolt holding them down. My shovel and full 2G were on the ladder when I got T-boned last week and they didn't go flying and/or explode.

 

[caain]

This is pretty much how I feel comparing 29erClan's OnShape masterpieces to my Sketchup crayon drawings:

The backyard foundry sounds awesome. I've seen some basic work with styrofoam models buried in sand where the molten aluminum pretty much vaporizes the styrofoam and takes its shape, but those guys were also melting beer cans for aluminum and the amount of cans (and slag!) was a bit off-putting.

 

[29erClan]

This is pretty much how I feel comparing 29erClan's OnShape masterpieces to my Sketchup crayon drawings...

:laughing3: That's exactly how I feel seeing your 3d print quality compared to mine! :rofl:

 

[outback97]

I took a closer look at the Rotopax setup. The base of the spacer can't really extend in the long axis because of how the fuel cans are molded, but it could be wider.

Like this (excuse the poor quality)

As far as height, with the nuts removed from the threaded rod and the spacer sitting on top of the strut channel, there's about 3/4" (actually more like 13/16 but you want a little space) of depth atop the spacer.

 

[29erClan]

Just finished my test. Good news and bad news. In order to be a good casting pattern I need to scale it up by the 2% plastic shrink factor plus another 1.5% or so aluminum shrink factor. Bad part: max printer capacity says no. Good part: except for some minor damage cutting off the raft it worked.

It's really cold outside and I don't wanna go get the red one, so I'm testing it on the water can. Same size, 2G.

The height ended up around 1-2mm below the center line. The idea is to use one on each side so this is good.

The mounting surface is darn close to flush. (The circle is about 0.312" thick.) And you get to see my print quality troubles there at the bottom.

And since @caain led me down this octoprint rabbit hole...

Nothin but the best! Genuine clothes pins are my camera crew.

 

[caain]

Just finished my test. Good news and bad news. In order to be a good casting pattern I need to scale it up by the 2% plastic shrink factor plus another 1.5% or so aluminum shrink factor. Bad part: max printer capacity says no. Good part: except for some minor damage cutting off the raft it worked.

I try to avoid rafts like the plague - seems like there's always some scars after removing them. That said, they are a necessary evil at times! Give me a shout if you want me to print off one of these for you in a larger format. If you're just using it for a casting, I can print it with some 'structurally sound, but aesthetically displeasing' filament I have.

And since @caain led me down this octoprint rabbit hole...

Nothin but the best! Genuine clothes pins are my camera crew.

Sorry about that.. but I maintain that it's worth it in the end! Before I printed a camera mount, my crew was masking tape and a telescope barrow lens. The barrow lens setup was actually a better camera angle..

 

[29erClan]

Give me a shout if you want me to print off one of these for you in a larger format. If you're just using it for a casting, I can print it with some 'structurally sound, but aesthetically displeasing' filament I have.

Thanks! I may take you up on that offer. But probably not until closer to summer. Need to setup the foundry first.

Sorry about that.. but I maintain that it's worth it in the end! Before I printed a camera mount, my crew was masking tape and a telescope barrow lens. The barrow lens setup was actually a better camera angle..

Excellent! The other Pi I was looking for has the eyepiece adapter for the telescope. I was dabbling in astrophotograpy/timelapse stuff before the move. Just haven't managed to find/unpack everything yet.

Speaking of... sorry about so much off topic in your thread @outback97, but when I found the PiCam I also found a few of the old dash radio mounts I made years ago. Yours if you want them.