The problem with OnShape and Fusion 360 is that if (when?) the services are discontinued your designs go away. You can keep the STL/IGES files but they aren't very useful if you need to quickly tweak a dimension. I've been bitten before by Fusion360 refusing to work (in offline mode) without an internet connection because it had decided it was phone-home time.
Whilst it doesn't have all the features of the usual commercial packages (Solidworks etc), SolveSpace is great, cross-platform, a single binary and my preferred open source solution for simple 2D/3D cad jobs [1].
FreeCAD [2] has also come along a lot if you prefer something more like the traditional packages, although I found some annoyances with it's dimension and constraint system when I last used it ~6 months ago due to the fact it has two different sketching modes.
SolveSpace is fantastic, and it's impressive that the entire parametric CAD package is ~2MB, it just never ocurred to me to use it for this. I'll give it a shot, thank you.
You're right about the proprietary/cloud nature of the previous alternatives, which is regrettable because Fusion is a desktop program, and could easily just be saving files locally.
I hope FreeCAD becomes a great alternative soon, because Fusion really needs competition in the space.
Nice. I had a similar problem when I rode my bicycle to work daily. I really didn't want to have to carry anything more than my phone.
I ended up hacking a bluetooth earpiece into a remote after seeing the idea online. It was 100% reliable over a period of over 2 years.
Having it mounted in the open like that seems like it could have a few drawbacks. I would still be concerned about water damage, even if you don't plan to ever be out in the rain. What about the fasteners you used? Are they rust-proof? Things mounted on my bicycle that have any metal parts seem to wear out over time, and plastics seem to take on some weathering, possibly from sun.
There's definitely going to be water damage on the plastic, PLA isn't very water-friendly. I'll buy some PETG to print it later on, it should be much more weather-resistant and durable. The nuts and bolts need to be rust-resistant too, yes, although I can always just change those after a while.
The good thing about having a 3D printer is that a replacement part is just 20 minutes away.
I just keep a traditional garage door opener in the inside breast pocket of my vest and jacket. Easy to close the garage when I pull out, easy to open it as I'm coming down the driveway. Harley-Davidson has an opener I could get and install directly into the bike (with a pushbutton on the "dash") but it's more than I'm willing to pay since my current solution works well enough.
Huh, I've never heard to keep weight off the keyring. I imagine this is to avoid unnecessary force on the ignition assembly? Obviously you wouldn't want to put several lbs on there, but it seems like small items would be fine.
Regardless, cool project. I'm planning to do something similar, as soon as I can get an indoor space. I might go even more hidden, and hide it under the lip of the gas tank or etc.
I was dubious at first too, when the motorcycle mechanic told me that, but then my car mechanic (completely unrelated) said the same thing, so I took all my keys out of the keyring.
Apparently, weight leads to the lock "loosening up" and can make the key "stick" a lot, unable to turn because the rods no longer align as well.
> I might go even more hidden, and hide it under the lip of the gas tank or etc.
I was thinking about doing that and connecting it to the bike battery as well, but I couldn't find a place that was easier to reach (and that wouldn't require me to lay cables all over)...
Nice, Stavros. I've been thinking about the same thing; having my current remote inside a jacket pocket and attempting to poke through the fabric to the button is distracting.
Thank you! I was thinking of publishing this to Thingiverse, but the enclosure is so ad-hoc that it would hardly be of use to anyone. Maybe I'll just publish the Fusion source, though.
> This is because if, when finally screwing the parts together, the screw has to thread its way through, then the gaps between the parts won’t tighten when you tighten the screw, because there’s no travel between them.
That's why wood screws are only threaded partway up their length. Since these screws are self-tapping, they need to account for the problem you correctly identify here, where the screw can't clamp the parts together properly because they cannot move relative to one another as the screw is tightened into place. Ending the thread partway up the screw solves this by permitting the part nearer the screw head to move freely along the shaft, so the fastener can clamp them together properly as it's tightened.
The machine screws you're using, conversely, are threaded all the way up to the head because they are not designed for self-tapping, but rather to be used in holes which have had threads tapped into them. That's why they are giving you the trouble they are. Happily, there are a few different ways to make that trouble go away!
Making the entire screw path wide enough that the screw doesn't have to tap any threads, and securing it with a nut, is one option, and as you've seen, it can work. On the other hand, you lose something in clamping force, because there's less bearing surface, and you also have to choose between machining (or designing) a nut pocket into the part, or having the nut and the end of the bolt stick out past the profile of the case.
Another option, which replicates the benefit provided by the design of self-tapping screws, is to make the screw hole wider, but only in the part nearer the head, and leave the far part's hole narrow enough that the screw will tap threads into it on the first insertion. This way, you have the part near the head free to tighten, which solves the problem you saw with your first designs, and you get the maximum clamping force possible from the screw without having to tap threads for a machine screw - and, with a carefully chosen (or trimmed) length of screw, you can also have the path end in a blind hole in the far part, so that the only part of the screw visible in the finished item is its head. (If you care, of course.)
And a third option, naturally, would be to actually tap threads into your screw holes - but you need a tap set for that, and I'm not sure there's much point. You need taps to cut threads into metal, because metal is pretty hard, and you need something very hard to cut it cleanly so that your screws, which are only pretty hard themselves, aren't ruined when you try to use them. Plastic, on the other hand, is very soft, so you're not actually hurting anything by letting your screws self-tap. You just need to adjust your design to account for it.
Ah, damnit, yes, this was the second thing I wanted to mention in the post (having the last part be tighter so the screw threads its way through) but forgot to write it up in the end.
Thanks for the reminder, that's exactly how these designs should work, you're spot on.
One other solution is that whoever it was in hollywood that first declared fanny packs to be 'uncool' needs to be 'drawn and quartered'. My little tiny remote is easy to access while i'm on my bike thanks to this amazing technology called a fanny pack.
I don't know how easy it would be, even with a fanny pack. There's going to be other stuff in there too, and even hitting the button when I'm holding the remote in my hand is hard with a glove, as the buttons are almost recessed. This design has the button protruding, making it much, much easier to press.
[+] [-] blutack|8 years ago|reply
Whilst it doesn't have all the features of the usual commercial packages (Solidworks etc), SolveSpace is great, cross-platform, a single binary and my preferred open source solution for simple 2D/3D cad jobs [1]. FreeCAD [2] has also come along a lot if you prefer something more like the traditional packages, although I found some annoyances with it's dimension and constraint system when I last used it ~6 months ago due to the fact it has two different sketching modes.
1: http://solvespace.com
2: https://www.freecadweb.org/
[+] [-] StavrosK|8 years ago|reply
You're right about the proprietary/cloud nature of the previous alternatives, which is regrettable because Fusion is a desktop program, and could easily just be saving files locally.
I hope FreeCAD becomes a great alternative soon, because Fusion really needs competition in the space.
[+] [-] no_protocol|8 years ago|reply
I ended up hacking a bluetooth earpiece into a remote after seeing the idea online. It was 100% reliable over a period of over 2 years.
Having it mounted in the open like that seems like it could have a few drawbacks. I would still be concerned about water damage, even if you don't plan to ever be out in the rain. What about the fasteners you used? Are they rust-proof? Things mounted on my bicycle that have any metal parts seem to wear out over time, and plastics seem to take on some weathering, possibly from sun.
[+] [-] StavrosK|8 years ago|reply
The good thing about having a 3D printer is that a replacement part is just 20 minutes away.
[+] [-] jlgaddis|8 years ago|reply
[+] [-] phantom_package|8 years ago|reply
Regardless, cool project. I'm planning to do something similar, as soon as I can get an indoor space. I might go even more hidden, and hide it under the lip of the gas tank or etc.
[+] [-] StavrosK|8 years ago|reply
I was dubious at first too, when the motorcycle mechanic told me that, but then my car mechanic (completely unrelated) said the same thing, so I took all my keys out of the keyring.
Apparently, weight leads to the lock "loosening up" and can make the key "stick" a lot, unable to turn because the rods no longer align as well.
> I might go even more hidden, and hide it under the lip of the gas tank or etc.
I was thinking about doing that and connecting it to the bike battery as well, but I couldn't find a place that was easier to reach (and that wouldn't require me to lay cables all over)...
[+] [-] adrianpike|8 years ago|reply
[+] [-] spthorn60|8 years ago|reply
[+] [-] StavrosK|8 years ago|reply
[+] [-] throwanem|8 years ago|reply
That's why wood screws are only threaded partway up their length. Since these screws are self-tapping, they need to account for the problem you correctly identify here, where the screw can't clamp the parts together properly because they cannot move relative to one another as the screw is tightened into place. Ending the thread partway up the screw solves this by permitting the part nearer the screw head to move freely along the shaft, so the fastener can clamp them together properly as it's tightened.
The machine screws you're using, conversely, are threaded all the way up to the head because they are not designed for self-tapping, but rather to be used in holes which have had threads tapped into them. That's why they are giving you the trouble they are. Happily, there are a few different ways to make that trouble go away!
Making the entire screw path wide enough that the screw doesn't have to tap any threads, and securing it with a nut, is one option, and as you've seen, it can work. On the other hand, you lose something in clamping force, because there's less bearing surface, and you also have to choose between machining (or designing) a nut pocket into the part, or having the nut and the end of the bolt stick out past the profile of the case.
Another option, which replicates the benefit provided by the design of self-tapping screws, is to make the screw hole wider, but only in the part nearer the head, and leave the far part's hole narrow enough that the screw will tap threads into it on the first insertion. This way, you have the part near the head free to tighten, which solves the problem you saw with your first designs, and you get the maximum clamping force possible from the screw without having to tap threads for a machine screw - and, with a carefully chosen (or trimmed) length of screw, you can also have the path end in a blind hole in the far part, so that the only part of the screw visible in the finished item is its head. (If you care, of course.)
And a third option, naturally, would be to actually tap threads into your screw holes - but you need a tap set for that, and I'm not sure there's much point. You need taps to cut threads into metal, because metal is pretty hard, and you need something very hard to cut it cleanly so that your screws, which are only pretty hard themselves, aren't ruined when you try to use them. Plastic, on the other hand, is very soft, so you're not actually hurting anything by letting your screws self-tap. You just need to adjust your design to account for it.
Hope this helps!
[+] [-] StavrosK|8 years ago|reply
Thanks for the reminder, that's exactly how these designs should work, you're spot on.
[+] [-] fergazen|8 years ago|reply
[+] [-] StavrosK|8 years ago|reply