The Geneva .... My first Hit and Miss Engine

[4156df]

Jim,
Thank you for putting those thoughts about the why of posting detail pictures into writing. I agree completely and have had the same doubts/thoughts about posting some of my photos. You've nailed the reason why exactly. Please keep posting just as you have.
Dennis

P.S. Enjoying the build.

 

[Deanofid]

Jim, I'm with Dennis, and in the same boat as you fellows. I put in quite a few setup photos on my threads knowing that the people working at, and certainly those above, my level may skip over them as old hat.

We didn't always know what we know, (however much that may be), and there is always someone who may benefit from seeing all the things we take for granted. Setups take time, and can be a large part of the job. If we want more people in the hobby, we need to show how it's done.

Dean

 

[tombstone]

Bearcar 1 Your right you cant beat using scraps for fixtures this is a milling fix I made to the mill slot in end cap shown, plunge cutter in, move top of fix forward, cutter out, job done it was made from scrap mdf off cuts, a piece of 3x 4 floor joist and ally angle plate it has made about 500 parts so far & cost nothing.The only problem I have with wood is trying to gas weld it.

 

[Troutsqueezer]

Rest assured Monsieur Bearcar1 that even though some of us haven't chimed in yet on your build that we are paying close attention. I've been capturing a number of images and text from this thread and I have downloaded the plans as well. Hit and Miss engines are in my future.

Question for you: Were there any parts you've made so far or ones that you haven't made that a HF mini mill and 7X10 mini lathe may not handle? Someday I plan on upgrading my lathe but I'm not sure when that will take place. Perhaps when I see the right thing pop up on Craigslist. Your equipment seems pretty robust.

-Trout

 

[bearcar1]

You are most welcome Dennis, it is and has been my pleasure. There are so many different levels of skill here at HMEM, not to mention the machines and tooling availability disparities. When I see some of the absolutely gorgeous engines that have been produced here it becomes a bit overwhelming and I begin to feel like, "gee, this really isn't up to that high of a caliber standard" and I'm sure others have felt the same way so it becomes more difficult, perhaps almost embarrassing to some to share their projects here, thinking that it would be looked at as crude or un-interesting. I want to see them all, I enjoy seeing how some fellows do work arounds to deal with a particular problem, not mention the final results of that builders efforts.

Dean, you are so correct. We all need to share our experiences, both successes as well as failures and detail how or why such projects or particular steps wound up that way.

T.S, the secret to your gas welding issue is you have to have the parts really clean ;D.

And finally, Trout', I am not familiar with the HF machines you are speaking of but as of this moment, I am using a Sherline mill until I can make moving arrangements to relocate my round ram BP to the shop and a South Bend lathe. The lathe is robust as you say as it will swing 10" over the bed. This particular engine I believe could be built on the machines you speak of but may be approaching the machines limits, i don't know for sure. The two largest pieces on this model are the flywheels at 3.500" diameter which I have not gotten to yet and the cylinder/coolant tank that you have had a glimpse of already. It measures 1.500" x 2.500" x 2.280". Having said that, the cylinder block would most likely be the biggest challenge using those machines but maybe not, as has been said here many times prior, there is usually "more than one way to skin a cat"

** disclaimer **
no harm was done to any animals during this post ;D

now then, Dean, have you and Zee come to some sort of trade agreement yet? :big:

BC1
Jim

 

[Maryak]

Jim, Dean and Dennis,

Your pictures and reasons for posting are IMHO absolutely what this forum is about. Thank you. :bow: :bow: :bow: In my own case I have found that making a build log encourages me to do better. (Just think of the extra stuff ups without it : : :)

Best Regards
Bob

 

[bearcar1]

Thank you all :bow:, I am glad (and relieved ) in knowing this is not a waste of everyones time and that as I said earlier, hopefully others will also gain some insight into different methods of accomplishing a task without some expensive tooling. Now, onward ... stickpoke
There is an insulator that is required in the ignition points setup that looked : simple enough so I decided to work on that to pass a few hours. The drawings do not specify what material to use so I settled upon a piece of what I believe to be polycarbonate, possibly Lexan, I don't really know for certain but it didn't machine too badly. I think that using a two flute cutter would have been better instead of the four flute I used but I slowed the spindle down and took shallow cuts and got 'acceptable' results. :shrug: I have a confession to make though, this part took me three attempts to get it right after missing the dimensions on the first attempt ???, and then by stuffing up the drilling on the second th_wtf1, and just like Goldy Locks the third was 'just right' Thm: (yeah right, what does that broad know about it anyway).

The worst thing about this material, whatever it is, was keeping the heat build up down or the material would start to deform :toilet:, especially when drilling. I initially tried to drill the part overhanging the side of the vise as shown above but due to the quite thin wall thickness and the friction from the bit it did not work out so well and I realized that I need to provide a means to reduce the localized heat build up. Without resorting to flooding the piece with coolant as would probably have been optimal, I set up the piece inside the vise jaws using a piece of aluminum stock on either side to act as a heat sink and to provide some better support to the thin sides. This worked a treat and the final results are shown below. I wish that I had a piece of Lucite for certain as I would like to have a part that I could vapor polish to a crystal clear condition but I'll settle for the frosty the snowman look for now.

BC1
Jim

 

[zeeprogrammer]

I'm still watching and enjoying the thread Jim.
I appreciate the detail and the tips and techniques...as well as any missteps you want to mention...I learn from them too.

P.S. There is no trade agreement between Dean and I. Negotiations are currently stalled. If they should start again, I'm sure we'll spare everyone's thread with the tawdry particulars and trash our own (read that as Dean's) threads. ;D

 

[arnoldb]

Jim, to quote Carl :

I'm still watching and enjoying the thread Jim.

- very good going indeed, and extremely informative :bow:

I fully agree with Yourself, Dean, Dennis and Bob regarding posting and the reasons for it ;D
To add something - I don't see the different methods used for machining, differing levels of tooling availability, and the "skinning of cats" to get around problems as a disadvantage; in fact I consider it to be a catalyst for thought - I've had a lot of "Duh" moments from seeing people do something on the forum - even if I needed to adapt those methods/ideas a bit to suit my shop environment. My own skills are still pretty low compared to most of the builds on the forum - but that's OK - by sharing my builds thus far, I've had a lot of very valuable tips passed back to me, and to others in the process. The best thing of this forum is that newcomers to the hobby don't get treated like ess-eightch-eye-tee, but are supported and helped, no matter how trivial their problems.

Kind regards, Arnold

(I got very lucky; I replied with the above yesterday evening, and it was one of the posts that went "missing". Usually I copy my posting to the clipboard before posting to prevent having to re-type in the event of a "glitch" - and while doing some work earlier today I "miss copied" some text, and when I pasted in my working document, this popped up ;D)

 

[bearcar1]

Thanks everyone for their understanding and support, it does mean a great deal to know that ones efforts are not going to waste. Arnold, I'm also so very glad that you have been tagging along on this adventure, as I said a while ago, your help is greatly appreciated. (he graciously offered up his assistance in hosting the photos for this series on his engineering site) :bow: Thank you.

I've been rather lax in the past few days and finally got motivated enough to set about on another part for The Geneva. With that fiddley and rather onery bit of an insulator piece finished it was time to turn my attention back to real metal again and brass was the material of choice again. The rocker arm pedestal seemed to easy enough, drill a couple of holes, do some simple profiling, yeah that would seem to be a good cure for a case of doubt and uncertainty. (you know, the feeling you get sometimes when not really sure in what direction to proceed or in my case, over analyzing the upcoming pieces to be built and the feeling of anxiety over the possibility of a major failure or screw-up)

To begin I used a short piece of square brass that was of the proper size and used the layout dye on its face, followed up by marking out the cut-to lines and finally locating and center popping the hole to be drilled in order to obtain the rounded bottom in the fork area of the piece. OK, that was easy enough, and so was the milling of the sides, using a .125" cutter once again as shown below.

Out of the mill and after drilling the above mentioned hole it was onto its side and some more layout was in store, this time to locate the hole for the rocker pivot. This was drilled and reamed to insure a round hole for the future pin.

Back into the mill and the center of the fork was milled out, this time cutting the sides down until the cutter *just* did clean up enough material to meet up with the sides of the large hole I had previously drilled to form the bottom. One could use the end mill cutter itself to do this step I suppose but I prefer to do it this way as I find it easier to remove the excess metal in small cuts as opposed to hogging the entire full width cut in small steps. (make sense?) In keeping with my "can't leave well enough alone" style, I wanted to make a radius at the base of the fork rather than the stark right angle the drawings were showing, this was also true in regards to that first hole that was drilled in the part's face. Once again not having the *proper* tool for this job (a small ball end mill cutter) I decided on trying this round diamond burr and found success in doing so. I just had to go slow and take smaller than usual cuts to depth.

"OK", I said to myself being rather smug in the notion that all was well, but NoOOoo! It was only when I went to drill the mounting holes in the foot that I discovered, *ahem* that when I changed the diameter of the cylinder head bolt circle, it moved them closer together and now if I drilled the holes in the piece I was working on to that dimension, I would not be able to get a nut on the studs let alone be able to tighten it down. SH*T! :fan: You dumb sack of rocks, Now what? ??? Hmmm......
What if I cut a "waist" into the bottom portion of the foot, THAT would allow me to drill the holes and have them line up as well as give clearance for the hold down nuts and that is what I did.
***NOTE TO SELF: Stop trying to re-invent the wheel and leave well enough alone. (yeah right, like that's ever gonna happen)

Also by incorporating this one deviation from the drawings, not only did I alter the spacing of the hold down holes, it also moved the pivot closer to the center of the head, meaning it also changed the ratio of the rocker arm itself. I am able to mount up the pivot pedestal 'backwards' and get the spacing back to where it should be due to its built-in offset but this just goes to show that one small, innocent and seemingly inconsequential change can lead to some major fubars (don't ask) in the overall layout of a project. Kind of like a domino effect, you alter one and it alters the one next to it and the cycle continues on etc. But, for the time being, "so far, so good, kinda" ;D

 

[Deanofid]

"so far, so good, kinda"

Yeah, I guess, Jim. I'm just missing the "kinda" part. That piece sure looks nicely shaped, and if it will do its job, you have it knocked.
Nice work on that!

Dean

 

[bearcar1]

Hi Dean, perhaps I should have re-phrased that to read "... I *think*". Meaning that even though I dodged a bullet this time around, what else is there that I can get myself into on this adventure. Of course you are correct in that the part was able to be made modified to work and still keep its overall appearance I just get weak in the knees when faced with unforeseen challenges at times.

"So far, so good" There, I said it out loud and you know what? I DO feel better. YallyHO!! Thnx.

BC1
Jim

 

[bearcar1]

Go get yourself a cup of tea or one of your favorite cold 'soft drinks' because this one is going to take some time. All of the steam engines I have made to date have always utilized a length of stainless steel rod for the piston/conrod or the piece has been a casting requiring one to either turn up some threads on the end or drill a set of holes for the later. Now, here, staring me in the face and laughing at me was a billet connecting rod that was in the shape of the ones you would see inside a automobile engine :-[. Egads! Well, with much trepidation and hand wringing (did I mention procrastination before ???) I began the journey, relying on much of what I have witnessed here on HMEM as a guiding light (Mom? is that really you??!!... No, ..*BELCH* it's just me, your imagination speaking to you, now continue) to fall back upon in my attempts to conquer this first time IC project. (whew, I'm glad of that but you really could use some Tic Tacs :big

To start off with, I flycut a couple of short lengths of aluminum bar that were a bit long, down to the necessary thickness. On the ends I did the usual layout and center pop of three locations. Two would become the holes for the clamping studs and the third was on the exact center of the piece and would be used to indicate the piece later on. The next step was to drill, counter drill and finally tap what would become the 'big end'.

This was easy enough until I realized in a brain fart that I had not counter drilled the first hole and had to go back and re-center the piece. I used the small ball end wiggler point to do this and after drilling, life was good once more.

Shown below is that central location I mentioned earlier being used to get the piece centered in the four jaw chuck in preparation for turning the outside diameter of the big end. These steps were all done prior to the end piece being sawn off.

After liberating the small, cap piece from the main bar both faces of the saw cut were faced and joined back together with 5-40 bolts for the remainder of the machining work.

This rather crude looking device (get yourself accustomed to them) is not an instrument of torture from the 16th century, although I suppose that if one were to close ones eyes and drift back to that period of time in France......... *AHEM* Oh, sorry. Now where was I, oh yes. What I reworked was a holding fixture from another build, it consisted of an aluminum disc that was screwed to the back of a piece of Oak with two rails spaced so that the conrod blank would just fit between them and then a set of holes drilled and tapped to receive clamping screws. I've said before, I don't have DRO in the shop, nor a large enough faceplate but brother, believe you me, when this is all over and I survive, I'm definitely going to have them as well as a rotary table!! *club* The prepared blank gets clamped into position and the whole thing is centered using the DI and wiggler routine and then the openings in each end of the conrod are drilled and then reamed to there specified sizes.

From here on, every step is a "mirror" image, that is what gets done to one side of the piece is duplicated on the reverse. I again went to the drawer of past used fixtures and found that with some minor modifications I could use this one to cut down the cheeks of the big end. The clamping button was made to the desired diameter so it was an easy task of advancing the cutter until it just nipped this piece and then using the micrometer stop, set the depth of cut, and after flipping the piece over on the jig and using the same dial settings, voila!, perfect symmetry at its finest.

Now just when you thought it couldn't get any crazier Rof}, I have one more for you, and then I promise that I'll stop. (no really :) This jig is very similar to the previous one, but seeing as how I was going to be reducing the thickness of the rod some more, I did not want to chance it flexing and decided to go with a more conventional looking faceplate arrangement to 'neck down' the small end. Also, in keeping with my previous track record of not staying to plan convention, I used a cutter ground with a radius rather that a squarish looking section.

Once the edge-on profiles were to my satisfaction, I turned to the more conventional methods as seen here to shape the sides. The drawings do not call out any dimensions for the taper so I had to do some "cut and eyeball, adjust, and repeat" in order to achieve a pleasing line. I wound up using 3* but I think I would like to go down to 2.5* or even 2* if ever I pass this way again. To hold the blank I first set the vice at an angle to the table using a protractor and clamped a short sacrificial bar in its jaws. I had previously marked out, drilled and tapped holes to correspond with the center-to-center spacing of the conrod blank on the centerline of this plate. The hold down buttons were turned to the target sizes and brushed with layout dye. When the cutter advanced far enough on the final cut to just graze the Blue, that was far enough.

Man, nobody ever said this was going to be easy!!! When the dust all had settled and I was able to collect my thoughts again, I found that I did not like the rather square looking big end and set about to make it appear more scale-like. (are you beginning to see a pattern forming here? I do)
First it was to trim down the back side just a bit and then counterbore for the cap nuts.

This of course was done after I made up some threaded studs to take the place of the cap screws. Then, using some filing buttons to round over the end I was at last done.

I want to cut a scallop into the sides of the rod but am going to wait a few days and catch my breath. There was a post up here a few weeks ago about that very thing so I will attempt to search for it. And I have to press a bronze bushing into the small end. That is not really necessary according to the plans but I want to put one in anyway. Whew! Thats all for now, so far, so good. Thanks for looking.

BC1
Jim

 

[Maryak]

Jim,

Very very nice conrod and some very useful setups. :bow: :bow:

Best Regards
Bob

 

[Deanofid]

That there is some nice lookin' con-rod, Mr. Jim. Properly sized nuts, and everything.
Beautifully done!

Dean

 

[SAM in LA]

Jim,

What a great lesson.

Thanks for sharing.

SAM

 

[bearcar1]

Bob, Dean, and Sam, I thank you. That was one Hell of a learning experience. I did manage to get the small end bushing made up and pressed in, so now the piece is officially finished. :bow:

I'm not sure at this point what to do next as I am running out of materials on hand and until my friend with the rotary table returns from his business in the UK I'm getting rather limited in my progress. Looking forward though, does anyone have any suggestions where I might find some small strips of Beryllium copper or spring steel, say .250" wide and 3.000" to 4.000" in length. I'll require these for the mechanical points system. Thank you all.

BC1
Jim

 

[GailInNM]

Jim,
I have BeCu that is 1.2 inches wide and 0.007 thick. It is in mill finish hardness so it can be easily cut and formed, but will need to be heat treated to bring it to spring temper. Heat treatment ranges from 550 degrees F for about 2 or 3 hours, 600 deg F for about an hour or 700 deg F for 30 minutes. Many domestic ovens will reach 550 Deg F so it's not too bad if you don't have a heat treat oven.

I also have steel feeler gage stock in 1/2 in width in most thickness up to 0.013. It is in rolls so I can shear some off. It works well for springs but is hard to machine.

PM me your address if any of this will help and I will drop some in the mail.

Gail in NM

 

[bearcar1]

Gail, you are truly a gentleman and a scholar for your gracious offer. I thank you, unfortunately I am looking for something just a bit thicker, in the .020" range. You have given me an idea though, perhaps I could use a blade from one of those cheapo feeler gauge sets. BTW, where did you find that piece BeCu anyway? I've looked briefly and the only thing I could come up with was some industrial place in India.

BC1
Jim

 

[GailInNM]

Jim,
If you are ordering anything else from Enco so you get above their $25 free shipping minimum, they have individual leaves 1/2 inch wide X 12 inch long for about $1.20 in that size range.

http://www.use-enco.com/CGI/INPDFF?PMPAGE=404&PARTPG=INLMK32

On the BeCu, in a previous life I needed some BeCu springs of a complex shape. About 10K of them. They were about 1/4 x 3/8 in flat form. Made a stamping die and a forming die and stamped them out. Then heat treated them. My local industrial supplier was able to get me the BeCu but the minimum order was more than I needed so I still have about 100 feet of the 0.007 thick x 1.2 inch wide. Since I only use about 2 inches a year I figure there will still be about 98 feet on the roll when I die so I try to give some away if anyone needs it.

Gail in NM