SwarfRat Enterprises has a set of free plans for a quick-release dial indicator holder that mounts on the front of a mini-lathe. The holder is made from a 5-inch long piece of .875-inch square aluminum stock. It also uses a quick-release lever from a bicycle seat or wheel that can be purchased inexpensively or salvaged off an old bike. It looks like it should be fairly easy to make, although it will require a mill.
I am thinking about making one but not to use with a dial indicator. With a little modification it might make a great carriage stop, much better than the one I’m using now. For those rare times when I need to measure the movement of the carriage I use a dial indicator with a large magnet mounted on its back. It’s easier to make and I can also use it on my mill, which makes it a really useful tool.
SwarfRat also makes instructional videos that will show you how to use a mini-mill or mini-lathe, how to repair them, and how to use some tooling like a rotary table.
You can buy them at their web site. SwarfRat also rents them for about $9 a week. That seems like a pretty smart move because there’s another company becoming well known for the how-to videos they specialize in renting. That company probably buys just one or two copies and keeps renting them out. My guess is that all those rentals destroy the sales of the companies that invested time and money to produce the videos and removes the incentive to make more videos we might be interested in.
But for some strange reason SwarfRat does not rent all of their titles, only a few of them. And I’m disappointed because they don’t rent their video about the rotary table, which is the one I would really like to see because I just bought one. They also don’t provide any sample videos and I can’t find any reviews of their products. So I’m not going to be taking a chance and spending $44 to buy a copy.
I am a big fan and admirer of Jan Ridders. He is a talented and prolific designer of Stirling, flame-eater and internal combustion engines that are both beautiful to look at and fascinating to watch operate. Jan generously shares his plans for free and you can also frequently find him answering questions on the Yahoo Barstockengine discussion group, a group that I highly recommend if are interesting in building one of Jan’s designs or some other engine that doesn’t require castings.
I have not built one of his engines yet, but I have been gathering the materials needed to build his Coffee Cup Stirling and I have made some practice parts. That engine, like most of Jan’s designs, has some features that almost make it a work of art, like the spoked flywheel, the finned power cylinder and the connecting rods with decorative holes. It also uses bearings and a lot of brass. These features require extra time and skill to make and they increase the cost of the materials and effort needed to obtain them.
Jan just designed a new easier-to-build version of that engine. Instead of a spoked flywheel it uses two CDs mounted on an easy-to-make hub. Balancing the engine should be easier because a small weight is added to the flywheel instead of drilling small holes in it and slowly enlarging them as needed. Silicon sealant is used to attach the top and bottom plates of the displacer cylinder instead of six machined brass spacers that need to be tapped and then used with screws that are countersunk. The new engine also does not use any ball bearings. Instead it uses “point bearings” that do not look hard to make.
A glass tube is used for the power cylinder and the piston is made of graphite. Graphite is also used to make bearings for the crankshaft. I am sure that Jan chose these materials to minimize friction, which is absolutely critical when building a low temperature differential Stirling engine. I was initially concerned that it might be difficult to obtain them in the right sizes and then fabricate the parts, but it doesn’t look like that is going to be a problem. I easily found numerous sources on the Internet and learned that it is apparently not that hard to cut a piece of glass tubing to length, even if it is made of borosilicate or Pyrex. Using glass is also an inexpensive way to make a cylinder. The working cylinder for the Coffee Cup Stirling is made from a piece of 30mm (1.2-inch) diameter brass, which could be costly to buy.
I would say that the biggest obstacle to building one of Jan’s LTD Stirlings might be finding an affordable large-diameter transparent tube for making the displacement cylinder. That is what has been holding up construction of my engine because you need to know the dimensions of the tube in order to make the top and bottom cylinder plates. Jan suggests looking for a suitable piece of packaging to use. I did find a wholesale-club size package of Slim-Jim snacks that was almost the perfect size but I am reluctant to use it because it looks cheap and would detract from the appearance of the engine. I know others have had the same problem and there was a recent discussion about it on the Barstockengine group. I plan to pass along some of the suggestions that were made at another time.
The plans are written in Dutch and English. The units are metric but I don’t think you are going to have any problems converting them to English units and using standard size metal stock if that is your preference.
Jan usually asks that you to send him an email request if you would like a set of his plans but he has kindly given me permission to make them available for download here (PDF, 2.9 MB). As I said, Jan gives his plans away for free, but I do know that he’ll accept a small donation via PayPal “only if you are very satisfied and feel called upon.”
Would you like free plans for a gas-powered 4-cycle engine that is a proven and easy-to-build design?
Joe Webster designed this engine to be quick, inexpensive and easy to build. It doesn’t have any parts with super-critical dimensions and you don’t need a rotary table or other expensive tooling to construct it. The plans are well drawn and include two pages of construction notes.
This is what is known as a “bar stock” engine, which means it does not use any castings. It uses flat and round metal stock that can be purchased from almost any metal or machine shop supplier It is not a big engine so the cost of the metal should be modest. Joe suggests making the 3.75-inch diameter flywheel out of an iron dumbbell purchased from Wal-Mart to save money.
The engine uses some components that need to be purchased, like a couple of gears, a spark plug, points, condenser, ignition coil and piston rings. The part numbers and vendors are listed on the plans and they are all readily available, I’ve checked. Joe recommends you also buy and use a carburetor for a radio-controlled car engine, although he does include drawings so you can make one if you want.
I could say more but the engine’s web page is a better place to get more details. You can download the plans there, see pictures, watch a video and hear it run. Joe explains his reasoning behind the design and lists both the engine’s pros and cons. You can also find out about some of the engines that others have been built from these plans.
Webster Engine Works also has plans for another engine, although these cost $12. The plans are for the Next Generation EZE – a .056 cubic-inch quick-building model airplane engine made from bar stock.
Purdue University’s Mechanical Engineering Machine Shop has plans and instructions for building a machinist clamp. The drawings are in PDF files and the instructions are in a Microsoft Word Document. If you don’t own a copy of Word then you may need this free Word Viewer.
The instructions are pretty detailed and even tell you what speeds to use. But they assume you are using their machines, which are obviously equipped with DROs.
They also have plans for a pen holder and picture frame.
SwarfRat Enterprises has a set of free plans for a quick-release dial indicator holder that mounts on the front of a mini-lathe. The holder is made from a 5-inch long piece of .875-inch square aluminum stock. It also uses a quick-release lever from a bicycle seat or wheel that can be purchased inexpensively or salvaged off an old bike. It looks like it should be fairly easy to make, although it will require a mill.
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