Beam engine at double scale--

[Brian Rupnow]

I spent this morning making "fiddly bits"---The valve actuator lever, the cross shaft, and the shaft that hooks up with the rod from the eccentric. There is a lot of work in that little brass lever---and then in a fit of misguided enthusiasm I drilled and reamed the hole for the cross shaft to 1/4" diameter instead of 3/16" like the drawing calls for!!! Jeez, I hate it when I misread my own drawings. Not wanting to remake the part, I took a peice of 1/4" cold rolled shaft, turned it to 3/16" diameter except for the last 1/4" that fits into the lever, and silver soldered it into place. It looks fine, and nobody will ever know except me and the gazillion people that read these internet postings. I took the afternoon off and went to a hotrod show with my 31 Model A roadster pickup. (won third place for "best street rod")--It was actually a sunny afternoon---we've only had about 3 sunny afternoons all summer here.

 

[Brian Rupnow]

Someone on another forum asked about my "other" hobby----hotrodding. This is my current hotrod. I have been building cars, showing cars, and drag racing for over 40 years now. Back when the earth was young, in the sixties, I ran a rail dragster with a 455 Olds engine in it. I built this car 4 years ago. Since I have had every other style of model A that old Henry built, I decided to go for a roadster pickup this time around. Roadster pickups are scarcer than hens teeth in Canada, so I built this one from a 2 door sedan. I shortened the sedan body about 5 feet, cut the top off, molded the tops of the doors and the top of the cab at the belt line, and built the box from scratch. I boxed the original frame, designed my own 4 bar parallel link suspension front and rear, and kept everything on a stock 103 1/2" model A wheelbase. I'm running a 4" dropped I-beam front axle with a transvere leaf spring with reversed eyes, a 1998 S10 rearend, and a small block Chev V8 with a turbo 350 automatic. The cab is 6" longer than a stock model A pickup, and the box is about 18" shorter than stock. I do all my own chassis building, bodywork, and paint. I designed and built the convertible top and top frame, however I had the actual sewing of the top done by someone else. I have a room full of trophies that I have won with this car, but I needed a break from hotrodding, so I bought the lathe and mill and started building model steam engines about 6 months ago.---Brian

 

[Kludge]

Someone on another forum asked about my "other" hobby----hotrodding.

*whimper* ... That brings back some memories! I never built or owned one myself (I drooled over quite a few, though) but I used to have a "magic ear" for tuning, which pleased the owner of the first garage I worked in even though he wasn't sure about having a reputation as a "hotrod garage". On the other hand, I brought business and he liked that part.

Someday, I'll put in my blog what would have happened to my International straight truck if I'd been able to keep driving for a living.

Thanks for the memories, Brian ...

Best regards,

Kludge

 

[Brian Rupnow]

No magnificent progress today, but I did get one more "fiddly bit" made---The LOWER VALVE LEVER. It is made as per drawing. I'm not certain that a single #10-24 set screw is going to lock it to the shaft sufficiently, but then again, there will be very little load on it, as all it does is shift the steam valve, which should slide very freely in the cylinder. I may get bold this evening and redo the bore in the eccentric hub..

 

[CrewCab]

Hi Brian, I've been away for a few days but it's good to be back and catch up, your engine build is one I've been following with interest ;D ........... to be fair I'm amazed how you manage to get so much done as well as having a full time job/business to run etc ....... perhaps a "time management" workshop would be a useful thread ........ I know it would be good for me ;D

It all looks to be coming together well and I'm sure it will be up and running pretty soon ............. one non-technical question mind, there apears to be a few marks on the copper base .......... or is it my monitor / eyesight ???

atb ........... please keep posting Brian, we are all really enjoying it

Dave

 

[Brian Rupnow]

Crewcab---That copper is horrible stuff to machine--it doesn't just cut--it smears. The copper was 3/4" thick to begin with, and I used a 1" four flute end mill to reduce it to 5/8" thickness. Those swirly marks are the finish that is left after machining. I am pretty certain that they will polish out. I got my 4 new 8" diameter buffing pads from Eastwood today, so I plan on an all out 'BlingJob" when I get all the machining finished.---Brian

 

[rake60]

Brian as of this moment this thread has been read 1581 times.

That should show the interest it has developed.

I know I'm looking in on it every day.

Rick

 

[Brian Rupnow]

Brian as of this moment this thread has been read 1581 times.

That should show the interest it has developed.

I know I'm looking in on it every day.

Rick

It must be generating some interest---I just checked the site that my download link for the plans connects to, and the plans have been downloaded over 400 times.---Brian

 

[Brian Rupnow]

Well Sir!!! I'm as happy as a pig in mud!! (And thats happy). I set the flywheel and eccentric hub up in my lathe last night, and drilled the hub out to 5/16" diameter. I then machined a peice of mild steel (actually the shank of a 3/8" bolt) to slightly greater than the 5/16" hole, coated it with loctite 638, and with my bigger meaner hammer I "force fit" the new peice into the hub. I left it up on my bandsaw all night with a 100 Watt bulb shining on it for heat. Today at noon (on my lunch break of course) I reversed the jaws in my 3 jaw chuck, gripped the flywheel by the outer diameter, and made sure it was dead tight up against the face of the chuck jaws, then center drilled it, drilled it with a 7/32" drill, and then reamed it with my 1/4" reamer. I then set it up in my mill/drill and with a 0.153 drill, I went thru the existing 10-24 setscrew hole and drilled out the new "sleeve" and retapped it. It runs very true now, with no wobble at all.

 

[Brian Rupnow]

A fellow known as Georgo on the Home and shop Machinist forum has found an error on 2 of my drawings. The thread on the end of the piston rod should be 5-40 and the thread in the piston should be 5-40. I haven't made those parts yet, so hadn't found the mistake. I will post this information on the websites that I am running. ---Thank You Georgo---If anybody else notices anything fishy, please let me know.---Brian

 

[Brian Rupnow]

New piston and piston rod drawings

 

[Brian Rupnow]

No, I haven't abdicated, nor ran off with the milk maid. I was at an all day custom car show on wednesday with my hotrod, and then had to work like a fool all day yesterday on real "work stuff" to get caught up. In the picture you will see that I have finished the "PISTON GUIDE ROD" and the "PISTON GUIDE ROD SUPPORT" and added them to the model. They are both built exactly to the drawings. Just for a hoot, this morning I hooked the electric drill onto the crankshaft, and ran the machine at a low RPm. It sure does look pretty with that beam going up and down, and the rod that goes over to operate the valve doing its thing, along with the flywheel rotating and the orbit performed by the rod that runs from the crankshaft up to the end of the beam. I think this is going to be a really neat engine to see running under its own power.---Brian

 

[Brian Rupnow]

This afternoon I was finished my "real work" early, so spent a few hours doing "play work". I have been a bit worried about the cylinder head, as it is one of those things that require doing a set-up in the 4 jaw chuck, as the diameter that fits down into the cylinder is offset from the square cylinder shape. I could have cheated and turned up a large peice in the 3 jaw chuck, then trimmed the flanges to achieve the offset, but I had a small length of 1" x 1/2" brass bar stock left in my stockpile of brass bits. It is against my nature to rush out and buy anything new, if I can utilize a bit of scrap. It turned out okay, and it is a perfect fit onto the cylinder. Maybe over the weekend I will whittle out a piston and valve to fit in the cylinder.---Brian

 

[Brian Rupnow]

Things have progressed on the "beam engine at double scale" to a point where I want to see things going round and round and up and down--- I have taken great care to get very exact fits on all my mating parts, and therein lays the problem. I could turn the flywheel by hand, but it took considerable effort, and there was absolutely no "coast" to it at all. I tried some lightweight oil on all the rotating surfaces, but no dice. Now, I haven't made the piston and rod yet, but I have machined up some mild steel pins to replace the drill bits that appear in the pictures in my build thread. So---I figure if I don't get things rolling smoother than that, it isn't going to work. It was plain to see that the engine had to be "run in". How do you "run in" an engine that doesn't yet have the piston and valve made??? Well, inspiration---I chucked my 3/8" variable speed drill onto the extended end of the crankshaft, and let it run at a fairly slow speed for 15 minutes!!! 7 minutes of clockwise rotation, and about 8 minutes of counterclockwise rotation. Holy cow!!! What a difference it made. Now I can make it run like a finger engine by pressing on the piston end of the beam. If I give the flywheel a spin by hand, it will actually make about 3 revolutions, driving the beam up and down and operating the eccentric rod and the valve actuator levers and shafts. Tomorrow I will machine the piston and valve---I'm starting to get excited, wanting to see this puppy run!!!

 

[Bernd]

I have taken great care to get very exact fits on all my mating parts, and therein lays the problem. I could turn the flywheel by hand, but it took considerable effort, and there was absolutely no "coast" to it at all.

The problem is called "tool makers disease". If you make very tight fits on a steam engine it has a hard time running from all the friction.

A friend of mine once built a steam engine and made it to tight tolerances. He applied steam and it failed to run once heated up because the parts grew a bit and caused more friction. Usually a steam engine needs a bit of "sloppiness" built in to run.

Nice job on that engine. I'm sure it'll be a fine runner once it's been run a while. You got the idea of getting it broke in with the drill motor, so keep at it.

Regards,
Bernd

 

[Kludge]

Brian, this is one heck of a wonderful learning experience watching you go step by step through the engine's construction and handling the little irritations that come along en route. I can't speak for anyone else, but I am utterly fascinated!

Best regards,

Kludge ... waiting for the next installment!

 

[Brian Rupnow]

I did get a piston, piston rod, and piston rod end all made and fitted this morning, but I got so wrapped up in making everything fit right and slide smoothly that I got the darn thing all together before I remembered to take a picture. Tomorrow I will have it all disassembled again when I make and fit the valve, so I'll take a picture of the piston and rod assembly then.---Brian

 

[Brian Rupnow]

Bits and peices---peices and bits--I've been away for a couple of days, but I got back this afternoon and machined the straps that connect the end of the beam to the end of the piston rod. I made a big departure from the drawing here, and this is the reason why---My local source for brass does not carry any 1/16" x 1/4" brass like the drawing calls for, and in my opinion the straps in the drawings are a bit puny. I was able to purchase 1/2" x 1/8" brass, so I bought a length of that and machined it to 5/16" wide. So--the straps are 5/16" x 1/8". I silver soldered two peices of 1/8" diameter rod to one of the straps, and left the peices of rod too long deliberately. I called my "nuts and bolts" supplier today and ordered a dozen #5-40 domed hex nuts. When they arrive I will thread the ends of the rod and use the domed hex nuts to retain the strap that is not silver soldered to the 1/8" diameter shafts. I have to disassemble a few things now, and adjust the length of the piston rod assembly, and while I have it apart I will take a picture of it, as I missed it in the previous post.---Brian---and thank you "BIG BIG" to whoever gave me the additional Karma.

 

[Brian Rupnow]

As promised---Here is the piston rod assembly. Nothing real special here, made as per drawing, pretty well. The piston was very tight in the cylinder "as machined". I lapped it with toothpaste untill it slid freely. Now I think maybe it slides too freely!!! I find it rather difficult to be a good judge of this. These little engines are not very tolerant of pistons that fit "tightly" in the bores, and if the piston seems too loose, a couple of drops of 30 weight oil seems to make them seal up alright. I guess I will know for sure when I get everything all assembled and see if it runs.

 

[chuck foster]

wow you work fast.............i just can't imagine how fast you will be when you retire

just like kludge I'm totally impressed with the step by step posts you have been doing.
seeing you start with a bunch of drawings and showing us all the pieces as they are made and telling/showing how you overcome problems as they arise.

i really look forward to seeing the finished engine posted (and video) of it here on HMEM...........but unlike most of you guys i will hopfully get to see the finished engine next year at the cookstown steam show ;D ;D ;D

Brian..........keep up the good work and thanks again for all the interesting posts on this project (one karma com'in at you for that)

chuck