Loc-line/gorillapod style arms

[jsc]

In the time I've had my M2, I've tried out many different gorillapod-style flexible arm models, and none of them have been really satisfactory until I came across this one: http://stickvise.com/hacks/stl-downloads

The improvement is, each segment gets a locking ring that tightens the socket around the ball so that it won't ever pull out inadvertently.

The modules can be a bit finicky to print, the sockets don't join up for a while so the segments have a tendency to want to detach from the bed, but a good dose of your bed treatment of choice and going a little slower than usual (60 mm/s vs my usual 80 mm/s) does the trick.

[Tim]

I take it that you printed this. . . do you have a Stickvise, or were you just printing it on its own? If you have a Stickvise, do you recommend it? It looks like it should belong to my stock of critically valuable tools. . .

[jsc]

I have printed eight segments, printing some more now.

I don't have a stickvise, but I just ordered one. You can get similar PCB holders on ebay for $4, but I like the design of this one so I decided to splurge.

All I ever wanted in life was something that would hold two wires in perfect alignment as I try to solder them. I have yet to find something that would do that. The helping hands that came with my old Radio Shack soldering iron was super fiddly and the jaws would always fall out. A flexible helping hands thing I bought a while ago that relies on thick gauge wires for the arms works a little better, but the wires have hysteresis so you have to bend them past where you want them and hope they relax back just right. My printed arm seems like it should have promise in terms of position holding. If it's not strong enough, I may try printing adapters for actual loc-line.

[ednisley]

hold two wires in perfect alignment as I try to solder them

That's called "structural solder" and is a Bad Idea: the wires should have a solid mechanical connection before you apply solder to make a solid electrical connection. Solder is surprisingly brittle when flexed, so any mechanical load applied to the joint will wreck the solder joint in short order.

Ideally, after you twist the wires together, they'll stay put on their own. More often than not, you'll need one clamp to hold the whole mess in place, but it won't require fiddly alignment.

The fact that I make "the bigger the blob, the better the job" solder joints on occasion should not be held against me... [grin]
http://softsolder.com/2015/05/18/random ... re-layout/

[jsc]

Hm, prompted by Ed I took a quick tour of the internet to check. I've been doing it wrong this whole time!

Well, I'm sure it will still come in handy for other things, too.

[Tim]

That's called "structural solder" and is a Bad Idea: the wires should have a solid mechanical connection before you apply solder to make a solid electrical connection. Solder is surprisingly brittle when flexed, so any mechanical load applied to the joint will wreck the solder joint in short order.

I know it's not ideal, but I've used the three-handed solder technique plenty of times. Yes, solder is brittle, but on the other hand, unless the connection is in the open where it's going to flex, a quick bit of solder between two parts held next to each other is very likely to last a lot longer than whatever is the thing I'm soldering, given the short usable lifespan of anything electronic. Now, if it's my M2 printer I'm working on, I'm going to make sure that solder job lasts for years, 'cause the printer sure is going to.

[ednisley]

the three-handed solder technique

I've always regarded that as a major evolutionary failure: so many things would be so much easier with three hands.

Besides, then we could say "On the gripping hand..."

[jsc]

Re: stickvise, here's a printable knockoff of the design, if you have suitable springs lying around: http://www.thingiverse.com/thing:881269

On soldering, once I learned how to design and make (have made for me incredibly cheaply, that is) PCBs, I regard any time I have to deal with wires within a circuit as a failure mode. Sadly, they are still inevitable once you have to come off the board.

Ed, a gripping hand would certainly come in handy when tombstoning SMD resistors on a protoboard....

[Tim]

Re: stickvise, here's a printable knockoff of the design

Coincidentally, I just completely disassembled an old color laser printer for parts, so I have lots of steel rods, springs, etc. Not to mention enough stepper motors to build another 3D printer with. But plenty of material to build a few stickvise knockoffs. Thanks for the link!

On soldering, once I learned how to design and make (have made for me incredibly cheaply, that is) PCBs, I regard any time I have to deal with wires within a circuit as a failure mode.

Undoubtedly, the availability of cheap PCBs in small batches is a huge boon to the DIY community. I used to design boards as a grad student, and I still have a box full of old boards that went from massive wire-wrap jobs to nice, clean circuit boards over the course of a few years. I have not done wire wrap for ages, other than using the tiny wire wrap wire to do quick board repairs.

a gripping hand would certainly come in handy when tombstoning SMD resistors on a protoboard....

"tombstoning" ?

Anyway, there is a nice soldering iron attachment called "solder tweezers" that can be conveniently held in one hand and heat both sides of an SMD component at the same time. Only useful if you have to do a lot of SMD rework on boards with too many plastic components to get a heat gun on it or use a hot plate.

[jsc]

I was referring to Ed's photo and accompanying article, where resistors are installed with one end in the air. I'd only ever seen it done to save space with through hole parts. Apparently, it is also a failure mode in reflow soldering, and now, thanks to Ed, a viable prototyping technique (?)