Three cylinder Radial

[Russel]

The DTI is a few years old and hasn't been used very much until recently. I sure do love Starret tools! Some of the Starret stuff is overpriced like their venier calipers, but the DTI and the edge finder I have are bargains considering how well they work. Needless to say, they are well cared for.

Russ

 

[NickG]

Nice work Russel.

I have a set of Starret vernier calipers that my grandfather gave me - god knows how old they are. They are good put a pain to use compared to modern digi ones! Think I have a 1-2 starrett micrometer too that was picked up for a couple of squid from a car boot sale!

Nick

 

[Russel]

I've had people ask me why I use a vernier caliper instead of a dial or digital caliper. I just like the fact that a vernier caliper is very durable and doesn't require a battery. Now that I'm beginning to use my machine tools and actually make things, I find the vernier caliper quick and easy to use.

A lot of what I have learned here is that your brain is one of a machinists most important tools. I find myself planning how I am going to make a part, constantly consulting the calculator for working out dimensions (some of that is starting to happen in my head without the need for the calculator), figuring out how much potential error is present in my method and how much accuracy I really need. Compaired with that, using a vernier is childsplay. But, I didn't always think so.

Russ

 

[Powder keg]

I like Vernier calipers because you can "see" how much further you need to go. You don't have to add or subtract anything in your head or on a calculator.

Engine is looking nice!!!

 

[Metal Butcher]

I've had people ask me why I use a vernier caliper instead of a dial or digital caliper. I just like the fact that a vernier caliper is very durable and doesn't require a battery. Now that I'm beginning to use my machine tools and actually make things, I find the vernier caliper quick and easy to use.
Russ

Hi Russel, you project is coming allong extremely well.

I had a vernier caliper in my collection of tools. I couldn't use them very well due to my bad eye sight.

My next set were dial calipers that read 0-100-0, spacing was a little small and I didn't care for them all that much.

My third set was a 0-100 and I liked them the best. Unfortunately a hammer fell of its perch and annihilated those.

My present set of calipers are inexpensive import digital (LCD). At first I didn't care for them all that much, and I missed watching the needle circling the dial. But after a few weeks of use they became a part of me and I don't think I would go back to using a dial caliper. Yes, the battery needs to be replaced, but they are inexpensive if ordered online. They do offer some nice additional features. With a push of a button the become metric calipers and also provide exact conversion. With the "zero out" button they do handy calculations.

Use the tools that you feel comfortable with, and don't concern yourself with being pressured to use a tool or techniques that doesn't suit you.

I use paper and pencil. I been told many times "why don't you use a calculator". I prefer to use pencil and paper that will leave a trail to follow. With a calculator there is no trail and I make entry mistakes caused by again poor eyesight.

The goal here is making accurate parts and assembling them to make a running engine, and there are many ways to reach that goal

-MB

 

[Twmaster]

Like MB I too use a digital caliper as my eyes are also going to hell and tiny little tick marks are really hard for me to read on small mikes and things.

It doesn't matter whether you use a yard stick or a Starrett micrometer. As long as your project ends up the way you want it.

Your engine is coming along nicely. Bravo!

 

[cfellows]

Really fine work, there, Russell. I really like what you're doing here.

Chuck

 

[Russel]

Thank you for the compliments, Dean, Nick, Power keg, Metal Butcher, Twmaster, and Chuck! I am really enjoying this project!

I use paper and pencil. I been told many times "why don't you use a calculator". I prefer to use pencil and paper that will leave a trail to follow. With a calculator there is no trail and I make entry mistakes caused by again poor eyesight.

The goal here is making accurate parts and assembling them to make a running engine, and there are many ways to reach that goal

-MB

Yes, the one drawback of using vernier calipers is that I need reading glasses and/or a magnifier to read them. Of course, I need some magnification to see what I'm doing with the machine tools also, so no "extra" equipment is required.

I use a calculator quite a bit, but I also repeat calculations sometime to be sure that I remember the number correctly...no paper trail.

Reading some of Bogs posts, I ran across one where he mentioned that he writes down cuts as he goes sometimes to keep track. Well, after cutting too much a couple times I started doing that and found it a great help, especially if you are getting interupted sometimes.

Pencil and paper isn't a bad method.

Russ

 

[Russel]

Wow! I had to dig a little to find this thread. My apologies, it has been over a year. It is amazing how sidetracked you can get at times. I haven't abandoned this project, just sidelined it for a while.

Anyway, I've machined the cylinders. I didn't take photos during the machining process, but here is the cylinders after machining. I think the cylinder heads will be next. More to come, soon...

 

[Blogwitch]

Russ,

This engine is a slightly different take on Westbury's Cygnet Royale. Stew built one of those a while back, and I built the same one from castings a few years earlier, and if care is taken, they are so smooth while running, there are hardly any vibrations at all. They WILL reverse, after a fashion, if you make up a control valve to swap over the inlet and exhaust. Easily done after you get the engine running.

With regards to using notebook and pencil, I use them all the time to keep a check not only of what I have done, but before I even start to cut, I usually plan and write down the whole cutting sequence beforehand. Then once I go thru it a couple of times and double check things as I go, when I actually come to do the cutting, it is like I have done it all before, and things go very smoothly indeed. This is a very handy system to use if you have to make multiple parts, you always know which stage you are up to, and all the parts come out the same. The only trouble is if you get your calcs wrong, you can make multiple bad parts, all having the same fault. I have never done that yet, but I can guarantee it will catch me out one day.

Yours is coming along very nicely indeed, and I am sure you will end up with a great running engine.


Bogs

 

[Russel]

Hello Bogs,

I never knew of Westbury's Cygnet Royale, but after looking it up on the internet, I have to agree that the radial I'm machining is very similar. I'm using plans from john-tom.com, the Elmer's engines page, the #11 Radial. I really like the reversing valve on the Cygnet Royale! I may have to add one to my little project.

It is kind of ironic that you mentioned using a notebook and pencil in reference to my older post because after having to start over, machining a couple parts this last year, I have gotten into the habit of using post it notes to keep track of calculations while machining. It seem like once I got started using simple notes to keep track of the numbers the whole process got easier. Best of all, I don't find myself re-calculating because I forgot a dimension.

Russ

 

[ruzzie]

Hi All
Here is a Cygnet I finished earlier
http://www.homemodelenginemachinist.com/index.php?topic=11191.msg122488#msg122488

"http://www.youtube.com/v/E_UTqFTS-VM&hl=en_US&feature=player_embedded&version=3"
Cheers
Paul

 

[Russel]

Wow, I started out OK, but it is really taking me a long time to complete this project!

Anyway, I figured out how to calculate the cuts to make spokes on a flywheel. So, I made the flywheel for this little radial engine. One thing that I found helpful, an extra fine sharpe fits into the spindle my sherline mill. That allows me to check the cutter path on the part before removing metal.

 

[thayer]

Nice looking parts Russel. FWIW, I have used my mill as a plotter as well, though with a conventional fine sharpie. Black for the part outline and red to check the offsets.

Thayer

 

[mklotz]

Russell,

Re flywheel calculations: you may want to check out the FLYWHEEL program on my page (url in my sig below).

 

[Russel]

Thanks Marv,

Unfortunately, your program doesn't seem to work with the operating system that I'm using. I'm running Windows 7 Home Premium 64 bit, service pack 1. When I try to run the program I get the dialog you see in the post attachment.

It's funny, I kind of feel like you were reading my mind. I also think that a tapered spokes give flywheels a more elegant appearance. My next step is to figure out the math involved with cutting tapered spokes, so your post was right on the money!

I should be able to figure out everything using the Flywheel Calculations diagram that you included with the flywheel calculator program that you wrote. To calculate the straight spokes I used Google Sketchup to mock up a flywheel diagram and figure the cutting radius for the inner and outer edges of the cut outs. Then, again using Sketchup to measure the needed angles, converted from polar to rectangular coordinated to get the offset and cut distance for the side of the spokes. I made the curved cuts by moving a CNC rotary table with a simple program so that I could make a .020” deep cut (1/8” cutting mill bit) then move to the next spot and make another cut, continuing until I made it all the way through the flywheel. (See second attachment) After completing the inner and outer curved cuts, I used the hand wheels on the mill and moved the flywheel as needed for the spoke offset and cut the sides of the spokes.

If there is a simpler way, I'm all ears (or eyes and the case may be.)

 

[mklotz]

Use DosBox to run my programs on Windows 7/64. I've tried it on my wife's laptop and it works swimmingly.

 

[Russel]

Thanks again Marv!

DosBox did the trick! After working everything out manually for straight spokes, using your program feels like cheating! I guess we got to save time where we can.

Russ

 

[mklotz]

One of the advantages of enciphering all these computations in the form of a program is the fact that programs have perfect retention over infinite periods of time.

It's not unreasonable in my shop to go several years between the making of two consecutive spoked flywheels. My chances of remembering how to lay out the computations and do the rounding for rational values are vanishingly small. I'd have to rederive everything again. Even if I had committed the derivation to paper, studying it and re-connecting with it would take an hour or two.

The program, OTH, remembers perfectly how to do it and can perform the calculations and produce a results summary ready for printing in a few tenths of a second. And it never makes a math error in the process of doing so.

 

[Russel]

I've gotten a little more done on this project. At this rate, I hate to even estimate how long it will take me to complete it. But, I must say, I'm learning a lot and really enjoying myself.

Anyway, I machined the base and base spacer. Pretty simple work with a mill. Then the cylinder heads. The slight complication with the heads what the round part that fits into the cylinder. While machining the basic part on the mill, I center drilled the center point for the cylinder so that I could locate it with the lathe. The tricky part was clamping such a thin part in the 4 jaw chuck so that I could machine it out to the edge. I used a method from one of Bogstandard's posts, the flywheel one I think, where you use parallels between the part and the chuck face. After locating it in the lathe chuck and clamping it down snugly, I was able to slip the parallels out and machine the round spot without much trouble.

At the bottom of the first photograph you can see one of the cylinder studs. I cheated a little on that part, I used some old 2mm stainless steel bicycle spokes to make it. As it turns out, 2mm is a little undersized for a 2-56 thread, but after threading and trying it, it worked fine.

The screws for the crankcase cover were a bit of a challenge for me. In order to cut the screw driver slot I had to machine about a half inch of quarter inch steel and drill and thread it so that I could use it to hold the screw while I cut the slot with a slitting saw. I did to use the threading tool I made a while back and was very happy to see that it worked well. The screw heads still need a little work on the finish, but the basic screws came out OK. It's funny how I can spend hours making six little screws and get so much enjoyment out of the process. Heck, I could probably buy six 2-56 x .25” screws for a buck or two, but I wanted to make them myself. Oh, I don't have any photos yet, but I also make the two 5-40 screws holding the crankcase to the base.

Next on the list is to finish making the 2-56 nuts and washers for the cylinders.