Chris's Diesbar Engine Build

[crueby]

Thanks Michael! 

[crueby]

To bevel the edges of the pump crank webs, I took a look at the cutters on hand. I have 45 degree dovetail cutters, but the angle faces the wrong way. So, I picked a carbide carving bur with a large radius on the end, and used the middle of the arc to do the cuts:

That came out well. After that, made up the nuts for the ends of the crank pins, and started in on the assembly process. First, I have used some Loctite Retaining Compound to 'glue' the crank pins in place in the webs, using a short section of the 1/2" rod as an alignment tool. That end of the webs was not glued, that will be done later on the actual crankshaft rod.

I'll let the loctite set up overnight, and tomorrow I will drill for the taper pins on the crank pin ends. The assembly of the main crankshaft will be done the same way - slide on and loctite the webs in position, then drill for the taper pins through the main rod, and finally cut away the portion of the main rod between the webs. This process takes a couple days, but has worked out quite well on a lot of engines.

While that is setting up, I can work out the text file for the lettering on the pump crank webs...

[Kim]

That's a pretty clever way to get a bevel! 

So, it's actually got just a bit of a concave face on the bevel now, but it sure doesn't show up at all.

Kim

[crueby]

That's a pretty clever way to get a bevel! 

So, it's actually got just a bit of a concave face on the bevel now, but it sure doesn't show up at all.

Kim

Yup!  Tiny concave to the 'flat' section, but you'd need a powerful loupe and a straightedge to detect it. Saved finding a reverse-dovetail cutter, waiting for it...

[crueby]

Got word that the paddlewheel  parts I had laser cut are shipped, tracking says Friday delivery, will be interesting to see how  they came out. I've  turned up solid hubs instead of the many piece 3d printed ones, same overall assembled shapes. Will need to make the sets of cross links, will reuse the printed paddles. More pics this weekend  probably.

[PJPickard]

Hi Chris! What loctite are you using? For years I have used 609, High Strength Shaft Retaining Compound. But somewhere(I think here on this forum) someone mentioned another one that they recommended. BTW, as per usual I am enjoying your build on this unique engine.

[crueby]

Hi Chris! What loctite are you using? For years I have used 609, High Strength Shaft Retaining Compound. But somewhere(I think here on this forum) someone mentioned another one that they recommended. BTW, as per usual I am enjoying your build on this unique engine.

The version I  am using is 638, whick is thicker viscosity and  will handle a larger gap. The 609 is meant for close tolerance  parts only.
 

[Roger B]

Wonderful progress as ever     

I'm looking forward to seeing how the paddle wheel components come out 

[crueby]

Wonderful progress as ever 

I'm looking forward to seeing how the paddle wheel components come out 

So am I!  Just got a email from UPS saying it is out for delivery today, one day early. 

[crueby]

Couple things done yesterday afternoon between read/nap sessions out on the porch. First, made up the PNP-Blue text transfer for the lettering on the crankshaft. Did some testing with different fonts, comparing them to the original and also printing out on plain paper to get better measrurements, and settled on 4.5 point Bodini MT font. I printed out the PNP mask in both red and black, to see how they come out on the metal.
Also, with the paddlewheel parts on the way, I took a few minutes and turned up some hubs for the wheel. On the 3D printed version, this was done with quite a few pieces, but for the metal version I'm making the hub sides from single pieces. Still need to drill/tap the holes to mount the spokes to. I'll lay that out after I get the spokes and outer rims, and get a couple pieces assembled, so I can double-check the hole positions with the spokes bent to shape.

I also realized I missed something when making the upper frame rails. On the center pairs of rails, between the vertical post tubes, there needs to be one more tube. These are used to hold a rod from the curved eccentric link bar, to help guide it when its moving up and down with the eccentric. I had them in the CAD version, but missed them in the build since the plan I printed out was a top view, and the bearing block obscured them. Whoops!  A very quick fix, just needed to add one more set of tubes the same way the outer ones were done. Step one, drill for the tube with a scrap block on the outside to keep the drill from wandering off the side:

Then drill a short length of rod and loctite it in place. It all went faster than a shop-elf sneeze! You can see the new tub below the bearing block in the center of the rail. Glad I had not painted the upper rails yet!

Then got back to the crankshaft. Yesterday I had loctited the webs to the crank pins, and let that cure up till this morning. I got out the taper drill and taper pins, clamped the first web set in the mill vise with a piece of rod in the other holes to keep them aligned, and drilled a starter hole the size of the narrow end of the taper pin. This removes the bulk of the metal, so the taper drill just has to do the taper itself.

Followed that with the taper drill itself, which just had to remove a tiny amount of metal along the length of the hole.

The pins were then tapped in with a bit of retaining compound for good measure, though that is likely not needed. If there is any difference in the taper, the loctite will be there to hold things. Tapping in the pins with a hammer locks the parts together. After the rest of the crankshaft is assembled I'll come back and trim off the ends of the pins and file them flush.
The same thing was also done on the center webs for the pump.

I want to make up the parts for the slip eccentric bearings and adjustable stops next. Once those are done and on the main rod, I'll get the parts laid out on the main crankshaft rod and loctite them in place. Tomorrow I'll drill/pin them, trim the pins, and can saw out the remaining section of the main rod between the webs. Then can see about adding the letters to the center webs...

[Kim]

The paddle wheel hubs are looking great!  As are the cranks  

Kim

[cnr6400]

   

[crueby]

The paddlewheel parts that I had laser cut by FabWorks.com just arrived - they look great! The edges were all deburred, everything is nice and smooth. Checked the holes that will be threaded, tap goes right in so I don't need to redrill them. Accuracy looks quite good.
Here is a picture of the parts: two outer rims, 20 spokes/paddle-holders, and 10 links for the feathering mechanism. I've already started on the hubs (see previous post) and will make up the two sets of struts that act like bicycle spokes and hold the two sides in alignment, and will re-use the paddles from the printed version. Yes, there are a couple size holes in the parts - some are for screws, some are pivot points.

First step will be to make up a bending guide from a wood block - the spokes get curved slightly along the long straight section, and a tighter bend out near where they flare out and curve, so the three holes in a row are vertical where they cross the rim. Um, thats the second step, I need to tap the holes out at the end of the spokes first. The bends are shallow so no issues with cracking. With all the spokes tapped and bent, I can start running in the screws to hold them together, and measure for the hole spacing from the center of the hubs and get the hubs drilled/tapped to attach the spokes. Once that is assembled, I'll measure for the other struts I need to make, they are simple round rods with flanges attached on the ends. Ought to have the wheel together in a few days.

[kvom]

Here's a video I made at the Berlin Technology Museum 10 years ago.  This paddle engine is a compound, but it seems to have a lot in common with the Diesbar.

<a href="https://www.youtube.com/watch?v=WSRfnHVcVwY" target="_blank">http://www.youtube.com/watch?v=WSRfnHVcVwY</a>

[Michael S.]

That represents good progress on the crankshaft.
The individual parts of the impeller also look good.