Vederstein's Two Cylinder Double Acting Steam Engine

[davidyat]

Grasshopper here. I got interested in vederstein's 2 cylinder engine. In due course, I found he only lives 6 miles from me. We got in contact, visited and I decided to build one of my own. His plans are on this site. I wasn't comfortable making the cylinders out of bar stock, so he poured a couple for me. Here are pictures of my progress so far. The cylinders are roughed out, the piston, piston rod and cross heads are finished. Also the cylinder glands and cross head frames

. The engine block has been the fun one. Circumstances were such that I had to start with a 5 inch diameter, 5 inch long block of aluminum. I turned one end with enough length to use as a knob for clamping in the lathe chuck. Then it was turning and hogging out the innards. You can see the pile of aluminum shavings you end up with. The block is in the dividing head to shave the lands for the cross head frames and cylinders for attachment.

 

[davidyat]

Finished the first platform and worked and finished the second platform for the engine block. Cleaned up everything and checked the 8-32 thread holes to make sure everything was cleaned out. The inspection slots will be done later as they are not critical specs, just holes to tighten the bolts on the ends of the rods. Starting to look like an engine.
Grasshopper

 

[davidyat]

Today, I started the front bearing support. I had a piece of round aluminum that was a bit too big, but decided to use it anyway. I turned down about 0.600 inch in length until it fit snug in the engine block. Then it was over to the mill with the dividing head upright to be used as a rotary table. Got 2 slots done and will go at it again tomorrow. My bearing support will be a bit larger than the specs as the sealed ball bearings I got from China had an OD of 1.260 instead of 1.125 like you would get from McMaster Carr.
Grasshopper

 

[vederstein]

David,

Just make sure that you have enough clearance to get in there and apply oil to the connecting rods....

 

[davidyat]

Finished the front bearing mount. And the pictures will show why my nick-name is Grasshopper. (Always being taught and not quite learning it all) When I started to use the rotary table to round out the first side, I was taking a plunge cut of 0.400 inch with a 1/2 inch end mill. It took almost 20 minutes to turn the rotary table about 110 degrees. Ever so slowly. There was a little jiggling but not too much to concern me. When I finished and went to do the other side, I saw what happened. The chuck in the rotary table came loose during the rotation. The 3 socket head screws holding the chuck had almost backed all the way out. OUCH!!! Am I embarrassed. The other side was rotated and only taking out a 0.025 inch plunge cut. The results show what I learned. DON'T TAKE SO MUCH OF A CUT!!! It's only cosmetic and will still hold the bearing. I'm going to mount the piece then use the boring head to make the openings for the 2 bearings. I just might mount the front bearing housing horizontal instead of vertical with the good side up so I don't see so much of the botched side. And now that I'm done with the rotary table for now, I'll take it apart and use Loctite 242 on the socket head screws so I won't vibrate them loose again.
Still Grasshopper for now

 

[davidyat]

Started on one of the cross head frames. It was not fun. I set up the cylinder on the mill and progressively drilled the hole out to 15/16ths. Then set up the boring head. I had to use my 3/4 inch boring bar to get all the way through. No matter what I tried to do, I was getting chatter and not a nice finish on the inside. Tried boring down with low RPM, boring up with higher RPM. On the down bore, I would measure the hole and it didn't seem that anything came off the bore. So I would increase the RPM by a few 100ths and would up bore. Without changing amount of cut, I would see a good amount of material coming off. When I got the cross head piston to start to fit, I took it off the mill and started with lapping compound and a brake cylinder hone I had that would fit the bore. With some patience I got the bore to 0.995 and the cross head piston was 0.992. So I had about one and a half thousandths clearance on each side. With some oil, it slid nicely. You can see the finish of the bore with the chatter that I ended up with.
Grasshopper

 

[vederstein]

As for your rotary table issues, it looks like your end mill got jammed up with chips perhaps?

Were you using a two, three, or four fluted cutter? Was it too long and deflected during the cut?

...Ved.

 

[davidyat]

I'm pretty sure I took too deep a cut on the rotary table. 0.400 of an inch on the first side. And then I saw that the chuck loosened up on the mounting plate of the dividing head. My fault. I tightened up the bolts for the second cut and took 0.025 inch deep cuts for the other side and the results were so much better. I was using a 4 flute end mill and I'm sure the problem was taking too much off at one time.
Grasshopper

 

[davidyat]

Was out of town for a week visiting CA, family, friends and having taxes done. After 70 years in CA, finally made up my mind to get out of Dodge. Don't like it there anymore. Best decision I ever made.
Worked on the crankshaft this week. First time I constructed one instead of machining one. I made the parts and assembled them. I used some silver solder to weld everything together. I had some really expensive silver solder left over. 52% silver instead of 17% I think. When I bought the 52%, I paid $30 for 3, 18 inch, 1/8 sticks covered with flux. Don't care what it costs as long as it works. Then it was over to the mill to mill out the rod section I didn't need. Then over to the lathe to clean everything up. I luckily had an off set jig from another project that had 1/2 inch holes spaced 0.500 inch apart for another crankshaft I made. Everything worked out and all I have to do now is ease most of the sharp edges off.
Grasshopper

 

[davidyat]

Got the rods finished. I had the rod blanks cut and separated the rod from the cap. Then I machined a jig to hold the rods and put the jig into the dividing head that I used for a rotary table. The dividing head can be tilted 90 degrees. Put the rods together and drilled the holes for the wrist pins and crankshaft journal. I found out about sharp drill bits and brass. One of the rods at the crank journal end was grabbed and pulled out of the vise. I was trying to bore 2 at the same time. UUHH, no, don't do that again. I was hoping to lap the rods to the crank journal, not using the bronze bearing called for in the plans. Didn't like the results with a 1/2 inch bore, so got the bronze bearings, drilled the holes for them, split the bearings with a slitting tool and then lapped the rods and bearings. The results were much better. And I made sure I marked everything so they would go back together the way they were built and lapped. I did notice some threads on assembling cranks instead of machining them. So I took my finished crank, put it in the mill spindle and checked. At 5 1/2 inches away from the spindle, I was only 0.008 off. I'm not going to do anything at the moment. I will drill the engine block to accept the sealed ball bearings that will hold the crank and see if there is any binding. I really don't think there will be, but if there is any noticeable binding, 0.008 should be fixable.
Grasshopper

 

[davidyat]

Before I proceed, I would like to bring my Father, John, into the picture. I got an enormous amount of ability from both my parents. A brain that knows how to think and from Dad, a great deal of talent to use with my hands. Dad could do just about anything with his hands. He was a WWII Veteran and was shot down out of a B-24 Liberator Bomber and was a Prisoner of War of the Germans for 14 months. His picture is with this episode.
I took the block and enlarged the center hole to 1 inch. Then took it to the lathe and finished to within a half thousand of final. The bearings pressed fit and seated nicely and firmly. Then comes the moment of truth. DOES IT ALL WORK! Bolted everything together and it turns like butter. YAHOO! I could turn the block (without the rods) and the rod journal would always bottom out without me having to touch anything and it would turn effortlessly. Installed the rods and it all turns smoothly. Now to start matching everything else to fit.
Grasshopper

 

[vederstein]

Excellent! You're certainly doing better than I on the engine.

...Ved.

 

[davidyat]

Well I finally put my mind to it and finished Vederstein's Twin Cylinder Compressed Air Engine. I thought to finish it was going to be a lot of trouble, but it went rather easily. Here's a video of it finally running.
Grasshopper

 

[kuhncw]

David,

Nice job. Your engine looks nice and runs well.

Chuck

 

[ShopShoe]

That is very nice. I like how it runs and accelerates smoothly.

Thank You for posting.

--ShopShoe

 

[davidyat]

Thanks, everyone on this site is so friendly and very helpful. I don't think I could do this without all your help.
Grasshoppper

 

[minh-thanh]

Nice job !
Congratulations !

 

[Ridge]

Great job, giving me motivation to finish my Husky.