'Useless Machine" Part Two

How's that for an imaginative title? It's meant slogging back and forth in the snow and ice between the house and my shop, but I have a working model of my version of the "Useless Machine", and a video. Now on YouTube, and embedded here. It views much better in YouTube, and can be embiggened. The video is, like all of my videos, just awful. One of these days I'm going to buy a decent camera, but not today. As you can see if you squint and look really closely, the GM2 gear motor worked just fine, and so did the plywood actuator arm, and the switches. The whole business is mounted on a piece of 1/4" plywood, so viewers (that's you three guys) can better see how it works and how it's constructed. Eventually this will go in a box. The 'C' clamp in the back is there to hold the whole thing vertical while I photographed it.

As almost always occurs with projects I throw myself into with no plan, some refinement and and improvement is in order. In particular, the lever switch that 'parks' the arm in the withdrawn position by killing power to the GM2 gear motor, doesn't play nice with the cam on the back of the wooden arm. The cam wants to crash into the switch, and rebounds slightly when it does, and that's not how a cam and follower are supposed to work together. So either the switch has to be repositioned or the cam redesigned or some of both (the most likely scenario).

There Have Been a Few Changes

Nothing major. I have a new picture in my profile. Sort of a caricature. My son says it's "spot on", an expression he probably picked up at the range. I think it's the hat. That's beer in my hand. Spaten Oktoberfest, if you must know. I've also had to change commenting so that word recognition is required to comment. It's irritating, but the mailbox was filling up with comment spam, which is a bigger irritation. Hard to believe for a blog this obscure. Comment spammers are like internet cockroaches.

I also discovered that I have followers! So I've added the followers widget to the right sidebar, so I can see you guys, and you can see each other. I'm still a little fuzzy about what the whole follower/following thing means, but there you go.

I have my version of the Useless Machine operating, and will have a photo and video later. I've also still making slow progress on the vertical steam engine. The weather here is not cooperating at all, and my shop is freezing.

Way Back in March...

..I announced with uncommon (for me) conviction that I was building a new vertical steam engine. Since then, events have conspired to keep me out of the shop. When I was able to spend time there I was working, not playing. Even so, I've managed to finish the bases for the new engine. I decided to build the engines from the ground up. Fabrication was straightforward. All of the work was done on my Clausing mill. The white styrene cleats are there to provide clearance for the flywheel, keeping it off the table top. Crank bearings are next, I think. Drawings for the engine can be seen by clicking the image of a vertical steam engine at the top of the right sidebar.

Components and a Schematic for 'Useless Machine'

I've collected the components I'm planning to use to construct my version of "The Most Useless Machine...Ever". Video of this machine is in the previous post. The version of the Machine documented on the Instructibles Website used a servo motor. Servo motors of that type require power, ground, and a positioning signal consisting of a square wave of variable duty cycle. Feel free to correct me if I'm wrong about that. A servomotor was used because that's what the builder had on hand. This requires circuitry designed around a LM555 integrated timer to generate the postitioning signal that makes the motor move in the desired manner. How bothersome.

I've opted to go a simpler and cheaper route (I hope!). I'll be using what's called a GM2 gearmotor manufactured by Solarbiotics. That's part of what you see in the first photo. The motors cost somewhere in the neighborhood of six bucks depending on where you purchase them. Mine came from Robotshop.us. I also purchased mounting brackets, and wheels that fit the double flatted shaft on the GM2 gearmotor. The rest of the components are a double pole, double throw (DPDT) miniature switch, and a micro switch with actuator lever. That's the rest of what you see in the photo. The switches came from a local RadioShack. I've also included a second motor in the photo to show the parts from a different perspective, and how they look prior to assembly.

For those of my three readers that might find such as this interesting, mechanical drawings of the GM2 Gearmotors, Mounting Brackets and Wheels can be viewed at the links provided. Enjoy.

A commenter at the Instructables site named sungam3D has drawn a combination schematic and circuit narrative that I'm reproducing here with his permission. That's the second photo. sumgam3D drew this using a program called Crocodile Clips, by the way. It's exactly what I'd intended to do, and it's a better schematic than I can draw. In fact, I think it does an excellent job of describing how the Machine should work. No point in reinventing the wheel. Click to embiggen. Yes, it's a perfectly cromulent word.

Now I'm going to go away and build stuff for a while. Feel free to amuse yourselves with the links and photos.

If This Doesn't Make You Smile...

then you're probably at the wrong Blog. It's billed as the Most Useless Machine Ever. You be the judge.

I must have one of these. Instructions are here.




Update: Motors have been ordered. I'm using GM2 gear motors by Solarbiotics. I ordered four, along with a few other bits and pieces. Everybody I know wants one of these, and the minimum order without service charge was 30 bucks, so four it was. How's that for an excuse? They are being delivered by Brown, and should be here in a few days.

The machine in the video was built using a servomotor that required a square wave control input, which complicates the electrical part of construction. Servomotors are also more expensive than the gear motors which are costing me $5.29 each from RobotShop.

I'll have more when the motors, etc. arrive.

How to Use an Edge Finder

I purchased a new edge finder a few months ago. Until now I had been using a wiggler type edge finder. Today was the first chance I'd had to use the new one. In the photo you can see a piece of aluminum that will eventually be an engine base in the mill vise, and the edge finder. I think I have managed to embed an excellent video (not made by me) showing how this type of edge finder is used. Enjoy.

Well, That Took Long Enough

I've finally finished the valve rods for the engine I'm working on. They were a bear to do too. I started with hardware store material, and gave up. The stuff was just awful. Better material yielded better results. The parts are by my standards small, and I was worried about being able to finish them at all, which is why I started with these particular parts. Had I been unable to finish them, I would have had to revisit my design.

The threaded portions of the rods are number three threads, and they're a bit less than an inch and a half long, to give some idea of size.

With luck, these little rods will be the valve rods that pass through the steam chest and operate the valve that passes steam into opposite sides of the cylinder, once the engine is finished. As usual, I'm building two engines at once, hence two parts.

The second photo shows one of the rods being turned with its' free end supported by a live center. When turning such small diameters, tool height becomes hypercritical. If your tool is too low, the part rides over it and bends. If it's too high, the cutting edge is held off the part by the metal below it, resulting in high cutting forces that deform or break the part. Either way, you get garbage. You can see some of the fallout from failed efforts at the top of the first photo. I used a steel tool instead of carbide. It gave a better finish on this particular material, and could be honed to a sharper edge.

I've been gone for some months. The entire time wasn't spent making these two little parts. Hopefully, I'll have more time to spend in the shop over the next few months.

OK, I'm Going To Build This

Well, I'm going to try to build this. It's a model vertical double acting single cylinder stationary steam engine of my own design. Bore and stroke, .750 inches. Wish me luck. I'm concerned about some of the smaller parts, and I'll do those first to keep from getting a lot of parts done and discovering that I can't finish things. I'm expecting Brown to deliver not one but five packages in the next few days containing tools and materials from various and assorted sources. It seems there are always a few more tools needed before starting any project, doesn't it? So, in the next few days my three readers should see me making parts. In the mean time, enjoy the pretty picture. If you click the picture, it gets bigger.

A Toolpost Adapter for Dremel Motor

Google Analytics has been telling me for some time now that many people are coming to the pages of this blog looking for a way to attach a Dremel motor to their tool post. Here's one way to do it. The nose of many Dremel tools have a ferrule attached by threads in the motor housing. The Dremel people use these threads to affix different attachments to the tools. You can too. I've provided a drawing with dimensions showing how to make an attachment that will allow you to fix your Dremel tool to your tool post. The odd shape of the part allows it to be held in a three jaw chuck for boring and threading. I made mine out of half inch thick aluminum, using my mill. If you don't have a mill, you can do the same thing using a band saw or even a hack saw, if you have the time and patience. It doesn't have to be perfect, just good enough to be securely held in the three jaw chuck. I threaded mine using a tool with a 60 degree point installed in a boring bar. It was the first time I had made any internal threads using my lathe. I did practice on a few pieces of scrap before trying it on my part. If you make one of these, do be careful while turning your threads. The "tail" of the part sticks out from the chuck, and can hit you or the ways or the saddle if you don't pay close attention to setting up your lathe and tooling prior to threading. Always turn things over by hand before starting your lathe with any setup, make sure you have stops installed to keep the saddle from traveling too far in towards the chuck, and keep your fingers out of the way. The last photo shows the Dremel motor installed in the tool post attachment, which in turn has been installed in the QCTP. Keep in mind that this is, after all, just a Dremel tool, attached by it's plastic housing, and have realistic expectations for what you can do with it. As always, you the reader are free to make whatever changes to this design that you please. If you do, I'd very much like to see your results. I'm also interested in seeing what you guys are planning to do with this attachment.

Larger Cross Slide Handwheel

If you are doing any amount of facing with the typical 9x20 lathe, you will soon notice that the hand wheel on the cross slide is just too small. Several other lathe owners have built larger wheels. Now so have I. This particular modification is really easy, and greatly improves the usability of the cross slide. My new hand wheel started out as a piece of half inch thick aluminum, three inches square. I laid out the lines for the features of the parts, and roughed it out with my modified ten inch woodworking band saw. That particular project has worked out really well. I've cut up to three quarter inch thick 4140 steel with no problems, and with reasonable enough speed through the part that the work didn't become tedious. The band saw seems to be handling metal cutting just fine. The rough work piece was held in my three jaw chuck using a 3/8 inch bolt. The head of the bolt is trapped behind the chuck jaws, and passes through the part. The part is clamped to the front of the chuck jaws with a nut. This method works fine to bring a rough part into a mostly round shape, so it can later be held in the chuck jaws, but it's not terribly accurate otherwise. In the photo there are rough areas still on the outer circumference of the part. Those will be removed later while holding the part from the inside recess that has yet to be cut. The part is next held with the outside jaws in the three jaw chuck, and a recess is turned to fit the factory hand wheel. I'm sure sizes will vary from lathe to lathe. I made my wheel so that the factory hand wheel was a sliding fit into the recess. Others have made these replacement wheels so they are pressed on or held in place with a grub screw that bears on the outer surface of the factory wheel. There are certain situations where the new wheel can interfere with the compound slide hand wheel, so it's desirable for the new wheel to be easily removable. Mine slides on easily and is held in place by a button head screw that fits into the threaded hole in the factory wheel where the handle originally fit. The original hand wheel does not have to be pounded or presses into place, is not modified in any way and is not marred by a grub screw. It fits securely, and has no play between the factory wheel and the new hand wheel.