Category: Projects

Hack for using a cheap vise…

Post author By Aaron
Post date September 6, 2015
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A few years ago I got so frustrated picking things up all night, I made one of the most useful tools in my shop. I was using it last night and realized it might be a trick worth passing along.

The problem is that cheaper vises “ratchet” when trying to hold a work piece that does not span the run of the jaws. So when the sides of the vise leave parallel, force gets applied unevenly to the work piece, which means the vise does a horrible job of gripping the work piece.

The solution I used since I was a kid was fairly simple – just put a scrap piece of the same width as the work piece on the other side of the vise. Its fast and work works, but it is generally a pain since you keep one hand one the work piece when loading and unloading the vise, and use the other to work the vise, which means the spacer usually falls through the vise to the floor. When you are cutting a lot of pieces, especially small ones, this means you keep having to pick things up off the floor.

After an evening of repeatedly picking the spacer up off the floor, I routed a small channel in a piece of scrap and glued another piece onto it to act as a lip. This prevents the spacer from falling through the jaws of the vise when loading and unloading the work piece. I did it without thinking as a quick hack, and inadvertently created a tool I use all the time. You only need to make one for each width you commonly use.

This trick makes tasks like cutting a bunch of pins massively faster.

Projects Prototyping Smart Matter

“The Turn”, my favorite part of prototyping

Post author By Aaron
Post date August 31, 2015
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One of my favorite moments in bringing an idea to life is when the assembly bench is loaded with parts, and you are about to start assembly of everything for the first time. I never thought of it in these terms before – but it is actually like “The Turn” in a magic trick. You are, as you assembly the various bits, taking a bunch of ordinary things and transforming them into something extraordinary.

Christopher Priest explains the parts of a magic trick in The Prestige:

“Every great magic trick consists of three parts or acts. The first part is called “The Pledge”. The magician shows you something ordinary: a deck of cards, a bird or a man. He shows you this object. Perhaps he asks you to inspect it to see if it is indeed real, unaltered, normal. But of course… it probably isn’t. The second act is called “The Turn”. The magician takes the ordinary something and makes it do something extraordinary. Now you’re looking for the secret… but you won’t find it, because of course you’re not really looking. You don’t really want to know. You want to be fooled. But you wouldn’t clap yet. Because making something disappear isn’t enough; you have to bring it back. That’s why every magic trick has a third act, the hardest part, the part we call “The Prestige”.”

Pictured here is the proof of concept I am currently working on for a smart matter extruder. So far it has been about 80 hours of non-stop printing, and I am waiting for the last mechanical part to finish printing so I can start assembly.

3D Printing

Making a Nerf Scope

For the last few years I have been working with my nephew on concepts like drawing things you want to build, making schematics, and keeping a lab notebook. We started when he was six, so at almost 8 he is comfortable with the processes. Still I was pretty blown away bow how comfortable he had become with the design process. He showed up for the visit with a bunch of designs. After a Nerf battle, we ended up designing and printing up a scope for his Nerf rifle.

Main thing that blew me away is that he drove the design process, iterating through a bunch of pretty different scope designs on paper before talking to me about what he wanted to build. Then when we were talking, we were able to refer to his drawings, even to the point where he merged two previous ideas coming up with a new one. It was actually really similar to how I normally work with professional designers. It was very cool.

Something I really liked about projects printing up my nephews designs is that he gets to work though failures, and learn about the power of iteration and value of measuring twice. In this case we designed the scope, but since we were not designing it to fit against a model of the gun – we were not checking clearances. So our first version looked good – but didn’t fit on the support rail.

My nephew got to figure out what was wrong with the design, then how to fix it. After that we revised the design and printed out a new scope, which you can see being tested here. Again, I was impressed that he was not paralyzed by disappointment, we just set to figuring out how to fix things.

Here’s an action shot of the scope.

All in all I plan on doing a lot more projects like this. Pretty much the only problems were the boring parts for my nephew. Watching the printer was cool, but after a while that changed into “hurry up and print”. Also my doing the CAD modeling while he watched was hard. I explained stuff and asked him questions so he was engaged while I implemented what he told me to – but it still taxed the attention span of a 7-8 year old. Still, over all we both had a lot of fun and learned a lot. I highly recommend projects like this if you have a printer and a little person.

3D Printing Toy making

A $6 Nerf Grappling hook

Started printing this version, which prints both the hook and the dart body. Problem with that is the printed dart body does not work with the compressed air spring driven Nerf guns or the electric Nerf guns dart accelerators. It was kind of a disappointment for my nephew.

http://www.thingiverse.com/thing:360571

My nephew and I did find this version of the grapping hook. It required cutting up a Nerf dart, but it worked amazingly well. It was also fast to print.

http://www.thingiverse.com/thing:604853

We bought a Nerf Jolt to use to launch the darts. Amazon has them for $6, and it works perfectly with the grappling hook dart. They also sell them in groups of 4, which would let parents and adults watching kids to stash them around the house. You know, in case you wanted to retaliate to any surprise Nerf attacks.

After we made the grappling hook, we designed and printed up a modification to the Nerf scope we designed so it clipped onto the Jolt. My nephew did the design and used calipers to take the needed measurements, and I did some translation into Solidworks for him.

With printers, VR, and AR all taking off someone seriously needs to make a decent CAD package targeted at kids. My nephew is a pretty impressive kid, but I was still surprised by how he walked through designing his scope. This was actually the second scope we built, so I’ll talk about his designing in another post, but I was impressed. He iterated a bunch of really specific designs on paper before telling me exactly what he wanted his scope to look like. He even tried out different lollipop and crosshair designs.

For “rope” we used a 15 foot section of dentil floss. Use the un-waxed type if you have a choice, it helps keep it from knotting. I added a front cross bar and spars to hold the “rope” on the grappling hook. Firing the dart would cause the “rope” to unspool as the dart flew, and winding up the rope kept it from getting tangled when not in use. Still, using the spars also meant that the kid firing the grappling hook had to re-wind after every shot. So I think I should have not added anything to my nephews design. It did provided an opportunity teach him what feature creep on a spec was, and that it is not your friend.

All in all we spent a good hour playing with the grappling hook, launching it at different things and trying to reel them in. The calipers we used to take measurement were also a bit of a hit in their own right. In retrospect though I would wait until the child in question was 9-10. The CAD modeling takes a good while even if you are keeping things simple and attention spans can begin to get exceeded.

3D Printing Projects

Round Two on Printed Lego Walkers

Post author By Aaron
Post date March 21, 2015
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The first LEGO walker was really cool, however it was more a single printed toy of the same size and scale of a LEGO mini-fig and not a LEGO toy in its own right. Looking around thingiverse a bit more my nephew and I found this walker design, which snapped together as a series of four custom LEGO pieces.

http://www.thingiverse.com/thing:462844

It is hard to make out details because I printed it in black ABS, but this walker really came out pretty sweet. I think I will modify this design before my nephew visits next, making the legs more easily detachable – but still – it was still really cool to be able to sit down with my nephew, pick out one toy to make from hundreds of possible options, and then just print it. I mean this is what the world is like when he is 8, he is growing up with that kind of magic being the reality of his world. How cool is that.

3D Printing Toy making Uncategorized

(3D printer + awesome nephew) = Toys!

Post author By Aaron
Post date March 13, 2015
No Comments on (3D printer + awesome nephew) = Toys!

So I have be playing with 3D printers for the better part of a decade – and I cant believe I never though of this! Most of what I do is making parts for prototypes – I haven’t been making toys.

My nephew is in town and I wanted to show him what you could do with a 3D printer. He’s 8 – and awesome – so we made some accessories for a Nerf gun under his direction. Once we were done with that though, we found this guys design for a mini-fig walker. (Design here http://www.thingiverse.com/thing:171087).

The designer painted his, which looks better, but I don’t really want to give kids painted parts to play with. They tend to end up in their mouths. Turns out there are a bunch of interesting designs for mini-figs out there.

At this point I pretty much need to design and make my nephew some new toys, but until I have time to sit down and design something for him myself, these designs look neat.

Lego Walker http://www.thingiverse.com/thing:462844
MiniFig Mech http://www.thingiverse.com/thing:22834
MiniFig Mech 2.0 http://www.thingiverse.com/thing:22835

Tools Watchmaking

New Watchmaker’s Lathe

Wahoo! My new watchmakers lathe finally showed up! I have wanted a watchmakers lathe like this, or a turn, for about ten years. Its hard to find a complete one in good condition.

Making a watch from scratch, meaning cuting everything from raw metal, is one of the projects on my bucket list. That project itself is long time off. For now I am just collecting horology books and tools and working on building basic skills. There’s a lot of skills and concepts to pick up.

So this type of lathe is made for turning very small objects between centers. What do I mean by very small? Well the lathe is bow driven, and it is not uncommon for people to use the core of a feather as the bow. The lathe dog that came with it is less than an inch long.

The lathe comes with a number of centers of different sizes, as well as several varieties I have never seen before. Several centers look hollow and bowed out forming a spring, so you can hold the work piece impaled on the pin. It’s a fascinating method for holding the work piece, but given the low masses involved – and the high stiction forces – I can’t see why it would not work.

I found the graver cross slide support is unusual in that it is only held in place by friction. The graver resting on the support translates into a downward pressure that should hold the cross slide in place. I was surprised at this design choice, since the lathe does use a screw turn just sets the cross slide support angle.

The turns are held in a bench vise, hanging out over the watchmaker’s bench.

So now to go make some very small round things!

3D Printing Prototyping

Impressions of the Printrbot simple

Post author By Aaron
Post date February 26, 2015
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The prototypes I am building required enough printing that I decided to get a second printer. Looking at what was available I decided to go with the Printrbot simple, and all and all I have been impressed with it.

Since I was in a hurry I spent the extra $50 and bought the printer pre-assembled and ready to print. Surprisingly it really was ready to print. I just slid it out of the box, plugged it in, and was printing 20 minutes later. Hey, I read the directions.

Even with the heated bed upgrade the printer was only half the cost of the Replicator Mini – so I was pleasantly surprised to see the print quality rivaling any Makerbot I have used. It definitely is better than the uPrint printers I have used. Given that, and that it does not use proprietary filament I have to say I am quite happy with the printer.

So what I was not happy with was my first real print turning into a blob of molten plastic. It is not as bad as it looks, just 2 hours with a hot air pencil to clean the head up. Recalibrating the auto leveling Z sensor fixed things and the printer has been running non-stop.

The one horrible thing is the Cura software they suggest using for the printer – so I am planning on at least switching to something like Pronterface soon.

So all in all I am very happy with the printer. The blob was my rushing things because I was impressed with the printer and wanted to play with it. I’ll probably build it an enclosure, and swap out the hot end eventually, but it was well worth the $750.

Thing a day

Thing a day, Thing #19 PCB mill Z axis motor

Post author By Aaron
Post date January 6, 2015
No Comments on Thing a day, Thing #19 PCB mill Z axis motor

Today’s thing, thing number 19, is a Z axis motor mount plate for the PCB mill. It will sit on the back of the aluminum plate and drive the Z axis. I’m still not wild about this as a solution, but it should do the job, and I want to get started cutting the PCBs for my prototypes asap.

I was going to call the thing a day experiment after 30 things, figuring it was more or less a months building stuff. Its not like I don’t have a huge pile of small projects – the very projects the experiment was attempting to clean out – but I seem to be gravitating towards working on parts of the very the larger project that were eclipsing the smaller ones. I think the “thing a day” idea was solid, but maybe only for one week every month or two.

Thing a day

Thing a day, Thing #18 PCB mill parts

Post author By Aaron
Post date January 5, 2015
No Comments on Thing a day, Thing #18 PCB mill parts

Thing number 18 is actually a couple of parts needed for making my PCB mill. I am building some proof of concept prototypes that will need a lot of very simple PCBs – so I am upping the priority of bringing my old mill back to life. Now that the holidays are over I want to get back into the pace of a thing a day. At least for another 12 things.

I swapped out the electronics for a Spark fun quad stepper board I had left over from a project a few years ago. So first thing was a PCB mount that included a small fan pointed at the motor driver. The electronics are only temporary, since they require a parallel port connection – but I want it up and usable fast.

The next upgrade was to add a spring-loaded table to the mill. This should let me level the table within a 1-2 thousandths of an inch. There’s a nut on each corner and tightening and loosening the nut in each corners changes the slope of the table.

Finally I mounted a new motor to an aluminum backing plate. I still need to make a stepper and lead screw mount in order to raise and lower the new z-axis. Once I have that sorted exactly I will trim the plates down a few inches to fit. After that I need to add back the optical end stops I ripped out of the mill when I started upgrading.