Chris' Build of a Lombard Hauler Engine

[crueby]

Hi Chris,
 So the rest of the  is in! So should have enuff to get thru the winter watching you in summer making progress!

Oh & when Zee brakes out the laser & starts vaporizing gaskets we'll have a heat source for more  ! Be interested to see how it goes Zee. Seen advertised here on the box a plotter cutter thingy for craft work & wondered how it would work on gaskets, might have to do some more investergating!

Cheers Kerrin

I've seen one in the catalogs from the model places too, wondered how well they actually worked.

Hmm, individually heat the popcorn kernels by laser beam....?!

[crueby]

Got to work yesterday on the crosshead sliders, which connect the piston and connecting rods, and run along the guide bars hanging off the engine beds. On the original, they were cast iron fittings with a thin bronze pad where they ran along the guide bars. For the model, I am simplifying them a little, making the entire part out of bronze. The closest bar stock I had in bronze was some 3/4" round bar, so I clamped that in a 3/4" collet in the square block, and milled it down to the size needed:

Then I sketched on the slots/holes to help keep the orientation correct through the next steps (lines just used to keep things oriented, not for milling to), and milled the slots where it will slide on the guide bar.

Then milled in the larger slots where the connecting rod end will go in,

and turned it 90 degrees to square up the round corners that the end mill left

There is a slot to separate the base from the con rod arms, which is too small for my end mills so that was done with a slitting saw, a couple passes to get the total height needed.

Thats all I could do with the parts still connected, so they were sawn from the main bar. The two bottom caps were left connected to each other for one more step.

And then the sawn edges milled to size, and then the bottom caps sawn apart.

Next step was drilling the holes for bolting the top and bottom parts together.



With the mounting holes drilled and tapped, here are the parts:

They still need the cross holes for the con rod drilled, and the arm ends rounded off, plus the holes in the end for the piston rods.

[crueby]

Finishing off the crossheads - drilled the holes for the conrod pin and the piston rod, and rounded the ends of the arms on the sander.

and turned in the small boss around the piston rod hole:

then test fit everything:

A little filing on one of the guides to get a smooth movement, and all is good.   

Then, continued on with the painting process on the engine. To get to the rest of the surfaces, I needed to turn the model upside down. Now, here is a view of a Lombard Hauler not seen recently, and usually only after the words "Uh Oh, missed THAT !@#%@ing turn!"

So, continued on with a first coat on the underside of the engine parts....

The differentiall itself is going to get a cover later on. Assuming I can get myself to cover it up, anyway! The original had a sheet metal cover over the diff gears, I do need to get a look at the real one next month to figure out where they put the joints, its at least a 2 piece cover, maybe 3, hard to tell from the pictures of it they have. Lots of things to take pictures of and measure while I am there!

[crueby]

And cranking along to the crank discs.... Since the cylinders are on the outside of the frames and the eccentrics on the inside, the crankshaft on the Lombard is a straightforward item with a disc at either end with a crankpin in it. So, started with a length of stainless bar long enough for both discs, left over from one of the other parts, centered it up and drilled/bored the hole to go over the end of the shaft.

Then moved the chuck over to the rotary table on the mill, offset for the crank pin, and drilled the hole for the crank pin with an M4-thread sized tap drill, down through both discs.

Then used the rotary table to offset to both sides, chain drilling a series of holes then milling the connecting webs out to form the balancing slots on either side of the pin hole.

After taking the chuck back to the lathe and parting off the two discs, here are the parts so far:

and where they go on the end of the crank shaft:

Still need to drill through the discs and the shaft for a retaining pin. Or may just loctite it in place. Though not sure I trust just the loctite, may do both. Or drill/tap for a through bolt so the discs can be removed if needed someday. Need to ponder on that one. Any suggestions?

Whichever way it is done, I need to pull the crankshaft out once again to do these steps. The two crank discs need to be 90 degrees offset from each other. The eccentrics for the valves are held with set screws, so they can be adjusted for timing the valves later on. With a little luck this will be the last time the shaft needs to come out - not hard, but a lot of screws and bearings to keep track of.

[Flyboy Jim]

Good progress Chris. 

You've been getting a lot of use out of those collets and collet blocks. I sure like mine!

Jim

[crueby]

Good progress Chris. 

You've been getting a lot of use out of those collets and collet blocks. I sure like mine!

Jim

Yeah, certain parts they are just the thing!

[Don1966]

Looking good Dog and still with you bud!......


Don

[crueby]

Looking good Dog and still with you bud!......


Don

Thanks Don!


Today was off doing family stuff most of the day, got in a little more paint work, and was about to do the crank pins when I spotted a brain fart on the plans, and the time went to fixing the 3d model and reprinting the con rod parts. Then time for a good nap!

[Flyboy Jim]

Looking good Dog and still with you bud!......


Don

Thanks Don!


Today was off doing family stuff most of the day, got in a little more paint work, and was about to do the crank pins when I spotted a brain fart on the plans, and the time went to fixing the 3d model and reprinting the con rod parts. Then time for a good nap!

Boy................. doesn't that just really tick you off when the designer makes a mistake like that?    Oh wait...............you are the designer! 

Jim

[crueby]

Looking good Dog and still with you bud!......


Don

Thanks Don!


Today was off doing family stuff most of the day, got in a little more paint work, and was about to do the crank pins when I spotted a brain fart on the plans, and the time went to fixing the 3d model and reprinting the con rod parts. Then time for a good nap!

Boy................. doesn't that just really tick you off when the designer makes a mistake like that?    Oh wait...............you are the designer! 

Jim

I just fired myself!!


 

[Flyboy Jim]

I just fired myself!!

 

I know...............good help is so hard to find these days! 

Jim

[crueby]

To finish up the crank discs, decided to attach them by drilling/tapping through the disc and the shaft for a 4-40 bolt, and also running in some medium strength loctite. Should hold plenty strong, and still allow it to come apart if need be.

The crank pins were turned up from some 1/4" hex bar, threaded on the end and the shank left to fit the bearings.

At this point, am starting in on the connecting rods, which will have a bronze bearing at each end, and have a u-shaped retainer and wedges at each end like the original. I've been wanting to try one of these for a while, nows the time!
The big end bearings started out as a length of bronze rod, drilled .1875 for the pin on the lathe, then switched over to the collet block on the mill for the rest of the shaping. I drilled deep enough to get both bearings out of this piece. With the square collet block, squared up the first two sides,

then turned the block 90 degrees to do the other two sides.

Next step was to mill in the slots so the bearings will fit into the con rod arm and brackets. Once the depth was set for the first side,

the height was locked in and the block turned 90 and a pass made on the other three sides. The edge of the block was indexed off the vise jaws with a straight edge to make sure the slots all lined up.

Then the table was moved over, and the slots for the other bearing made the same way.

With the first two bearings shaped, back over to the lathe to part them off, then take them to final thickness in the 4-jaw (don't trust the parting tool for exact thicknesses, unless I get it ground/sharpened/aligned just right, it tends to pull to one side just a little).

Here are the parts so far:

and a family shot of the engine with some paint on:

Next step will be to make the small end bearings, they look just like the first two, just smaller.

[b.lindsey]

You have been busy Chris, just getting caught up to your current progress...impressive as always.

Bill

[crueby]

Thanks Bil! Getting close to feeding in some pressure - con rods, valve rods/sliders to go...

[crueby]

Just like the big end bearings, the small end ones were milled out of round bronze bar, and the center slots milled in before parting off the two bearings.

The two smaller bearings ready to go:

And turned/threaded the small end pivot bolts:

Test fitted in place:

Next up will be the con rods and the u-shaped brackets for the ends. Here is a rendering of where I am going with them: