Bouch's workshop - 1.5 x 3.5 horizontal steam engine

[bouch]

Hi folks,

Years ago, (a dozen at least) I was at the Dublin, NH, antique engine show, and there was a fellow selling castings for a large horizontal steam engine out of the back of his truck. The engine was a 1.5" bore by 3.5" stroke, flywheel about 12" diameter, and a baseplate of almost 2 feet long. He was dealing as the "Barker Machine and Foundry Co." I bought a set of castings, and have never seen the guy again. I've also only seen one example of a finished engine, built by a fellow NEMES member.

The set of castings included the base, flywheel, cylinder, front and rear cylinder heads, the crankshaft throw, and eccentric strap.

I started working on machining the castings. The quality of the cast iron was quite good. Not a lot of hard "skin" on them, no voids except for a VERY small one on the flywheel, and no hard spots in the castings themselves.

The one downside was the drawings were hand sketches. I found that some of the dimensions were "to fit", and a few others were obviously wrong. There were also elements of the design I didn't like, and wanted to re-work. When other projects popped up, so I stopped working on the engine.

Fast forward to now... Here's what it looked like when I stopped working on it:



Due to a compromised immune system, I haven't been allowed to work in my shop, and it'll probably be another 6 months before the doctors give me clearance to start working down there again. So, to keep busy with various projects, I've decided to learn how to use Draftsight and make some "real" drawings for this engine. That way I can confirm the dimensions, and also figure out exactly the changes I want to make (and started making without really drawing things out!)

My first attempt at a drawing was the front cylinder head. I figured I would start with something "simple" but not overly simple.

Here's the original drawing provided by Barker:



And here's my first attempt at drawing using Draftsight:



And just for yahoos, here's a picture of what I've already done on the front cylinder head. Turned to dimensions, but I need to drill the holes for the studs and also the clearance hole for the piston rod on the inside.



The next item to draw will be the rear cylinder head.

Occasionally, as I get things drawn out, I'll be posting more of my Draftsight drawings until I'm allowed back in the shop. Then I'll start posting about progress on finishing the engine. Hope people find this interesting…

 

[kvom]

Draftsight is quite easy to use for me, and I've been doing all my CAD with it since it first was released. Your drawings look good, but I'd make a couple of changes. I'd use diameter instead of radius for both the outer dimension and the boss. Your engine looks about as massive as the Joy engine I'm working on currently. What's the weight of the casting set?

 

[RonGinger]

I remember that guy- I saw him a couple times at shows in Maine. He said he lived in Maine. I may have a card or something- I think he had a simple flyer or brochure. I will dig around.

Take it easy Mike, and good luck with the CAD. You might also look at freeCAD before you get to committed. It is a 3d solid modeler, and that is a much better way to draw now than simple 2D drafting. I bought Alibre, but recently made a 2 minute look at freeCAD and it looks good. Anyone tried it?

 

[RichD]

I think working with, and learning to use a CAD system is extremely useful for anyone that wants to build something.

It's not always easy to learn how to draw on a computer, but if you can overcome the initial concepts of using x,y,z coordinates and object snap tools, your drawings and work will always be accurate.

We all have our inclinations for one program or another. The truth is, all of the programs out there can produce accurate drawings. My favorite has always been the older DOS version 11 AutoCAD, but the solid modeling capabilities of the newer programs is hard to ignore. I find the learning curve just keeps on increasing since we always have some kind of idea or challenge to overcome.

Good luck, and remember to take advantage of streamlining and customizing the software you use. For example; you can draw an object and save it for future use in other drawings. My default drawing template has a drawing of my milling machine table on a separate layer that I keep turned off so it doesn't show. There's lot's of good books out there with tips on customizing your software.

Regards,
Rich

 

[akitene]

FreeCAD is indeed a very interesting 3D modeler although it's still crippled with a few bugs when rendering complex parts. It lacks a dynamical assembly module. Nevertheless it's perfectly free and very promissing.

 

[bouch]

Draftsight is quite easy to use for me, and I've been doing all my CAD with it since it first was released. Your drawings look good, but I'd make a couple of changes. I'd use diameter instead of radius for both the outer dimension and the boss. Your engine looks about as massive as the Joy engine I'm working on currently. What's the weight of the casting set?

I've been following that Joy engine build, and was surprised at how big it is. Quite a substantial engine!

Using diameter is a good idea. I'll probably change that.

Don't know how much it weighs. Don't have a bathroom scale, and its too heavy for my postal scale. Its definitely heavy! I just weighted the cylinder casting, and that alone is 3.5 pounds...

 

[bouch]

I remember that guy- I saw him a couple times at shows in Maine. He said he lived in Maine. I may have a card or something- I think he had a simple flyer or brochure. I will dig around.

Take it easy Mike, and good luck with the CAD. You might also look at freeCAD before you get to committed. It is a 3d solid modeler, and that is a much better way to draw now than simple 2D drafting. I bought Alibre, but recently made a 2 minute look at freeCAD and it looks good. Anyone tried it?

Yeah, I remember he was from Maine. Somewhere I have his business card as well...

Right now I think I'll figure out 2D before worrying about solid modelling in 3D... That's what I learned to draw/read. Maybe the next project I'll move to 3D.

 

[bouch]

Next drawing done, the rear cylinder cover...



Next up, the cylinder, and also the piston rod gland and cylinder cover/gland studs. The cylinder will probably take a few sessions, as I have to verify the dimensions of the ports and also take some modifications into account...

 

[RonGinger]

Right now I think I'll figure out 2D before worrying about solid modelling in 3D... That's what I learned to draw/read. Maybe the next project I'll move to 3D.

If you do 3d modeling drawings like you just did come free- just a couple clicks and they are done. There really is no benefit to learning 2d CAD first, just atart 3d modeling.

 

[ShopShoe]

I agree with RonGinger. If you are working for yourself, not making drawings for others to use, you can do things like rotate your model onscreen to show relationships and add dimensions to the 3D view only where it is important, and all the other dimensions are not there to confuse you.

--ShopShoe

 

[bouch]

Well, maybe I'll look at freeCAD over the weekend and see if I like it more than Draftsight. Can't hurt to try it since its free. I know I'm not in position to purchase either 2D or 3D software right now for various reasons...

 

[johnmcc69]

Hi Mike,

Nice start on the drawings. That's going to be a nice engine. I think you'll enjoy drawing it up as much as you will building it.

Keep up the good work!

John

 

[kvom]

If you're a veteran you can get a copy of Solidworks for $20 shipping fee.

 

[bouch]

Been a while since I posted anything on this thread... I've done a little work on the drawings, but was slowed down by a 7 week hospitalization in Nov/Dec for a nasty case of "PCP pnuemonia". Still dealing with after-effects from that, mostly muscle weakness due to being bedridden for that long, but sitting at "Draftsight" doesn't tax me too much...

Anyhow, I decided, for now, to stick with 2D drawing. I checked out freeCad, and just got horribly confused. Since every engine I've ever built was from 2D drawings, I figure I'll just stick with what I know and am used to for now. Maybe some other time I'll learn 3D, but not for now.

Anyhow, I'm pretty much done with the cylinder drawing and also the steam chest. Here they are:

http://www.homemodelenginemachinist.com/attachment.php?attachmentid=74667&stc=1&d=1422376613

The ports are very different than the original design, mainly because the steam chest I've designed is shorter. Originally, the steam chest was the full length of the cylinder, I've made it shorter, 3" long instead of about 4" long. The original design called for ports that were all 1/4" wide, with a 1/4" space between them.

What I did was get the plans for the Stuart Turner #1 that I built, and copied the port dimensions from that. I figure that if the ports are sufficient for a 2" x 2" engine, then they'll be good enough for a 1.5" x 3.5", especially considering the expansive qualities of steam. Might not be as good when running on air, but I can deal with that by adding more pressure

The one thing I still don't have on the cylinder drawing is the 4 holes to attach the cylinder to the base casting. That I still have to work out, but that'll probably be determined "at assembly". Also should probably put the hidden lines for the ports on the "end view" drawing, but that might get pretty cluttered, lord knows the top view is pretty busy with hidden lines...

And here's the steam chest:

http://www.homemodelenginemachinist.com/attachment.php?attachmentid=74668&stc=1&d=1422376613

And the two glands, one for the piston rod and the other for the valve rod.

http://www.homemodelenginemachinist.com/attachment.php?attachmentid=74669&stc=1&d=1422377268

I've also drawn the steam chest cover and all the studs for the cylinder ends, steam chest and the glands. I'm not attaching those here as they're pretty simple parts, and kinda boring drawings.

Next step is the drawings for the slide valve, the adjustment nut, valve rod, piston and piston rod...

 

[Herbiev]

Great to get the update. Looking great so far. May your health continue to improve. That pneumonia is a real cow especially when the doctors put you to sleep for a few weeks to strengthen the lungs. Looking forward to your workshop progress pics.

 

[bouch]

Been a while since I posted any new drawings, so seems like now is as good of a time as any...

First was to finish up drawing the slide valve and valve gear. Since this engine isn't intended to reverse, a simple eccentric valve gear will do. As mentioned earlier, I copied the port dimensions from my Stuart Turner #1, so I did the same thing with the slide valve and eccentric.

Here's the drawing for the valve, I'm not going to post the eccentric drawing as its fairly basic...



The eccentric strap is a casting, so I took the time to draw the outline accurately. Other than that, its a pretty simple drawing. I drew it both as "one piece" and also showing the casting split into the two pieces.



I haven't drawn the eccentric rod yet. The exact length still has to be determined, and that'll be dependent on where on the base the cylinder assembly and crankshaft bearings are located. What I figure I'll have to do is get everything built and assembled, and then make a temporary rod. Once its running, then measure the rod and make the real version.

Next was the piston and piston rod. The original sketches show a piston simply threaded onto the piston rod. I've built several engines like this, and I find that getting the piston concentric to the rod can be tricky if the threads are a little loose. So, what I did to solve this problem here is have corresponding tapered sections on the two parts. The tapered section should guarantee the piston is connectric to the rod, and the thread will only hold the piston in place (along with a locking nut).



That takes care of the parts in the cylinder assembly, so on to the crosshead assembly. The original sketches show two simple plates for the crosshead guide, and a somewhat crude, square crosshead. Back around when I bought the castings, I was at an engine show and there was an antique steam engine about the same size, and I took a bunch of photos of it, and kept them with the drawings.

Here's what the crosshead looked like on that engine.




The crosshead guides are pretty much what the original drawings called for, but the crosshead is much more "detailed", and there's adjustable "sliders" to take up any wear in the crosshead. I've decided to make the crosshead similar.




Due to the width of the crosshead, I can't put in the round sections, but everything else is reminiscent of the antique engine. (and I just noticed I never put in the radius between the main body and the round section the piston rod threads into. That'll be a quick fix!)

Another aside, every so often when I save the drawings as a PDF (to make it easy to print), Draftsight doesn't export the entire drawing. As you can see on the crosshead drawing, part of it is clipped off. Anyone know why this happens, and what I can to to make sure the entire drawing gets exported?

Next step is to draw the base casting, and work on where the cylinder, crosshead guides, and crankshaft bearing is located. Like the eccentric rod, I'll have to derive the connecting rod dimensions based on these locations. And like the eccentric rod, I'll probably make a temporary rod to ensure the derived dimension is correct before making the final part...

 

[bouch]

More work on the drawings...

The next thing I needed to do was determine the location of the holes to mount the cylinder on the base, the crosshead guides, and the guide for the valve rod. What I did was draw the base without any holes, and then copied a bunch of the other drawings and pasted them all together to make an "assembly" drawing. This drawing is looking down at the engine from above. I then used the dimension tools to measure where the holes were. For the crosshead guide, I pasted the piston/piston rod/crosshead as an assembly at both top dead and bottom dead center, and then placed the crosshead guides so they were close to centered.

Here's the assembly drawing...



Note that not all the studs are pasted. I figure placing one would be enough to verify the dimensions were correct. Also note that the glands for the piston and valve rods aren't there. I didn't think they were necessary for this drawing...

Making this assembly drawing also helped me discover an "incorrect" dimension. The plans called for a steam chest 3/4" deep. When everything was put together, the valve eccentric would be right up against the bearing block, basically acting as a thrust bearing on the crankshaft. (don't know if this was the designers plan or a "happy accident"). However, with the design of the eccentric and strap, the strap would have been rubbing against the bearing block, and probably the engine base as well. Since that surface of the base is an unmachined surface, I thought this was a bad idea.

So, I added another 1/4" to the thickness of the steam chest, moving the center line of the eccentric/valve rod out 1/8" from the bearing/base. This was done on both the assembly and steam chest drawings. Also had to re-work the drawing for the steam chest studs, but that was pretty trivial. All told, it took a few hours to re-do that work, but better finding the issue now rather than when everything was machined and I would have to scrap parts and make new ones!

I then modified the drawing for the eccentric so it would continue to act as a thrust bearing, just with a lot less surface area against the bearing block.

(I hope all that makes sense to the reader...)
The final thing I did on the cylinder drawing was locate the holes for the cylinder drain cocks. My father is picking up a pair from P. M. Research at Cabin Fever today, so I should have them Tuesday or Wednesday (not that I'm in a hurry for them, but picking them up does save about $10 shipping costs...)



And finally placed all the holes on the base drawing...



Not too much more I have to draw before I'm "done" with this phase of the project.

The only things I need to draw are the spacers to hold the crosshead guides, those will be pretty easy, I just have to decide what I want them to look like. I want them to be more than just round pieces, but I don't want them overly decorative as not much else on the engine is "fancy"...

I should probably make another assembly drawing, this one from the side, to verify the dimension from the top of the base to the centerline of the cylinder bore. That dimension is derivable from the cylinder drawing, so I don't "need" it, but I might draw it out for "completeness" sake.

I will draw the connecting rod and valve rods, but they won't be to the final dimension, so those won't be "finished" until later. The main task will be to draw out the split bearings I want to have on the connecting rod. I think it'll look better with that type of design, and with the design of the crosshead I need at least that end to have a split bearing or it'll be a PITA to connect the rod to the crosshead...

I don't need to draw out the crankshaft, the bearing blocks, or the flywheel as those have already been made. If I run out of projects to draw out, I might do it for completeness sake, but I have plenty of other things to work on. Until next time...

 

[bouch]

I did produce a "side view" assembly drawing, and I'm glad I did... Here's what it looks like now...

When I first drew it, the valve rod support bracket was 1" closer to edge of the base, so it was next to the cylinder. While there were not clearance issues (as is obvious by the top view), I didn't like the aesthetics of where it was. I moved it 1" closer to the crosshead guides. I like its current location much better.

Moving the holes in the base drawing was easy. Here's the updated base drawing

Moving things around on the top view assembly drawing took a while, but it confirmed that the new location still looked OK from above. I also had to modify the valve rod and eccentric rod drawings, adding 1" to the former and subtracting 1" from the latter. Not a big deal, just took a little time.

As you can see above, I've decided on the design for the supports for the crosshead guides. I tried a few different styles, and settled on a slight taper from the top to the bottom...

So, as of now, I'm done with the parts which needed drawing. I'm only about 10 days from having the health restrictions lifted, so I should be able to start working in the shop again very soon. My "immediate" projects are to finish the 7.25" gauge hand-pump cars I started building for my kids, the G.H. Thomas retracting tool holder for my 10" South Bend, and the Barker engine. Which project I work on any given day will depend on my mood, but as I want the hand-pump cars working for the Waushakum annual meet at the end of August, that'll probably take priority...

Hopefully the next post will show actual metal being cut

 

[bouch]

Been a while since I updated this thread, mostly because a) I had finished with the drawings, and b) I wasn't working in the shop. Well, I've finally started working down in the basement again...

A few years ago, I made a New Years resolution to not start a new project until I finish one underway. You've already seen the drawings I was working on during my recovery. So, since I have good drawings and a 1/2 finished project, that's what I've started to work on.

As with the drawings, the first thing was the cylinder heads. The front had been turned, but the mounting holes hadn't been drilled, nor the recess inside for clearance for the piston rod and the nut to secure the piston.

I mounted my "X-Y rotary table" on my drill press and indicated it in. Then I found that the tee nuts I had were too "thick" for the slots in the table. I put four in my shaper and took about 1/16" off the bottom and they fit fine.
Next was to mount the casting on the table, and move the X out by 1", the radius of the bolt hole circle centers. Centerdrill, drill, advance table 45 degrees (5 turns of the handle, each turn is 9 degrees), repeat 8 times.

The table has 4 slots, so I was able to drill all the way through on 4 of them, the other 4 I had to stop a little short of "through" to prevent drilling into the rotary table surface. Once done, I loosened the head, re-aligned those 4 holes so they were over a slot, and finished the drilling through. Once all were done I did a quick countersink on both sides of all the holes.

Then I mounted it in my lathe to drill/bore the inside recess. The largest drill the chuck would take is 10mm, but a 13/32 could just barely fit, so I used that to drill a hole 3/8 deep. Then I opened it out to the 5/8 finished size using a boring bar. I then used the boring bar to give a fairly generous chamfer.

With the rotary table set up, it was pretty obvious to work on the rear cylinder head as well. Repeat the above steps for drilling the 8 mounting holes.

Then I moved the X back to 0, and then out to 7/16. I drilled and tapped one hole for the piston rod gland studs, rotated the table 180 degrees and drilled and tapped the 2nd hole.

Once again, since the rotary table is set up, the next obvious thing is to drill the corresponding holes in the cylinder casting for the studs to mount the cylinder heads. But, the cylinder hadn't been machined to the outside diameter at the ends...

Since the concentricity with the bore isn't very critical, I made a simple fixture to turn the cylinder ends. I took a piece of 1-1/2 diameter steel about 4 inches long, mounted it in the 3 jaw chuck, and drilled/tapped a hole in one end 1/4-20. I then put the cylinder on this, and used a few large washers and a long bolt, and tightened it up right against the chuck jaws. Then I simply turned the end to dimension. Since the cylinder is only held in place by a bolt, I didn't take very heavy cuts, about .020 removed per cut.

When it was all done, it looked much better

Next step, as I already mentioned, is to drill/tap the holes for the cylinder head studs. While I'm doing that, I'll have the shaper plodding away cutting the steel I have for the steam chest and steam chest cover to dimension. I figure at the speed the shaper works, I'll be able to machine the cylinder, the studs, and probably get the piston rod gland done before the steam chest parts are to size...

 

[bouch]

Little more progress on the engine...

While the shaper has been merrily working away cutting the blank for the steam chest to dimension, I drilled and tapped the holes in the cylinder for the studs to hold the heads on. Then I made 16 10-32 threaded studs for the cylinder heads.

My estimate for how long the studs should be was a little off, once I had them made they should probably be about 1/16th shorter (for my "visual liking"

Here's a couple pics of drilling the holes (using the rotary table on my drill press) and the heads in place with the studs inserted...