Chris's Diesbar Engine Build

[cnr6400]

  That runs sweet Chris! Love the feathering action.   

[crueby]

That runs sweet Chris! Love the feathering action.   

Thanks  Jeff! It will make a great companion piece to the engine.   

[crueby]

They posted another video from last week's event at the logging museum:
<a href="https://www.youtube.com/watch?v=q5XTPJ-Gnfw" target="_blank">http://www.youtube.com/watch?v=q5XTPJ-Gnfw</a>

[crueby]

Got started shaping the eccentrics from the flat plate blanks I made the other day. First drilled/bored the hole in the center to be a sliding fit over the bushings on the crankshaft. Then made up an arbor to hold them, and drilled/tapped for a screw to ensure they did not rotate on the arbor during shaping - the rim will get grooved with a parting tool, and the center section will get openings cut in with a mill, and I don't want the parts to shift during any of that.

Then offset the arbor in the chuck to match the offset needed on the eccentric, and have the first one turned round:

Here is the first one to this stage. I took it off the arbor to turn the other one to the same shape. Since the screw will index the parts on the arbor, I can remove/replace them as needed. They are marked for which side goes against the arbor.

So, will get the other one turned round, then start in making the grooves in the rim for the follower arm to ride in. I'll also need to drill the eccentrics to take screws to hold the counterbalances on, and mill the openings in the sides. On the original engine, the eccentric halves are split vertically, up through where I have the hole, with bolts holding them together through the openings. For the model, the parts are way too small for that, so I have put hidden screws in through the sides across where I have the seam horizontally.

[cnr6400]

 

[crueby]

This morning I got the other eccentric turned to diameter, then used a parting tool to cut the slots in the perimeter for the follower arm to ride in:

Moved the chuck over to the rotary table to cut the openings. Started with drilled holes at either end of the slots\

then a 1/16" end mill to cut the outer sides of the slots, taking a series of shallow cuts till it was all the way through:

Then moved the arbor to the 3 jaw chuck, and widened the slots at the inner edge.

That finished the slots, with a wedge shape following the inner and outer edges

Next will be to make and attach the counterbalance plates which atach to the side of the eccentrics.

[cnr6400]

  Groovy! (sorry, worst eccentric pun this month) 

[crueby]

Groovy! (sorry, worst eccentric pun this month) 

You mean worst pun FROM an eccentric?      Well, we are all a bit eccentric to be in this hobby anyway.   
 

[crueby]

More video from the event at the logging museum
https://youtube.com/shorts/qKFRF7w837I?si=D4yL1iKTcUgRu5rQ

[Sanjay F]

You can those coming from miles away!

The covers on the radiators, are they for protection, or to get the engine up to temperature in very cold weather?

[crueby]

You can those coming from miles away!

The covers on the radiators, are they for protection, or to get the engine up to temperature in very cold weather?

The gas Lombards have sheet metal flaps that are hinged, lever up to the cab so the driver can adjust them. In very cold weather they could close them as needed to keep the engines at a good temperature, summer open them for more cooling. The trucks were made for both town highway department and building contractor use. One or two of them were used early on to plow the road between two of the towns in coastal Maine, the first time those roads were plowed in the winter, using blades around 15 or 20 feet wide. The roads usually drifted in with snow and were closed most of the winter before that - coastal ferry boats relied on instead. The grey one in the video has a dump bed, powered by a take-off shaft from the main transmission to a gear driven curved rack gear on the bed. The green one has a fixed flat bed. And the steamers were just used in the winter with skids in place of the front wheels, to haul trains of logs (up to 300 tons at a time) out of the woods to the river staging area or the sawmill - replacing many teams of horses. We have the wheels on the front for our summer events, have run it a few times at the museum in the winter too. The engineer/fireman stay warm, the steersman freezes his elves off - the smokebox doesnt give off all that much heat. So, the steersman actually got paid more! Many of the owners put a little open-front shack around the steersing position to block the worst of the wind.

[Sanjay F]

Thanks for explanation.....

Be frozen, but 'For a few dollars more'! 

[crueby]

Today is counterbalance day. The flat plates were clamped in place on the eccentrics, and drilled/tapped/countersunk for some flat head 1-72 screws:



Then set up in the four jaw chuck on the rotary table and aligned the hole in the eccentric to the center of the table, and milled out the end of the plate slightly larger than the hole so it would not rub on the crankshaft bearing

then offset the arbor used on the eccentric to center the counterbalance in the right spot, and milled around the edge of the blank

I have one more counterweight to trim around the outside, then I can affix them permenantly to the eccentrics with some loctite and trim off the screw ends.

[cnr6400]

  Guilty as charged re being an eccentric (and having made quite a few as well) 

I hope there wasn't too much disc ussion needed to get the shop elves busy with the counterbalance disc... 

[crueby]

Guilty as charged re being an eccentric (and having made quite a few as well) 

I hope there wasn't too much disc ussion needed to get the shop elves busy with the counterbalance disc... 

Discussion  stopped as they fell over from being too eccentric!