Chris's Mann Wagon Build

[crueby]

Chris:

What are the concentric rings on the back of the holders for?

Don

Those are just the tool marks from turning them down on the lathe - the 'wings' are thin, so the flexed a little and left visible but not feel-able rings.

[crueby]

Got the caps for the crankshaft bearing holders made this morning. Started by cutting down the holders and milling in the opening for the caps (forgot to take photo of that). Then made up the caps themselves from some square bar stock, drilling matching holes in the cap blanks and the bearing holders. With the two caps bolted together, I bored a starter hole in the center so that I could do the finish boring with the parts assembled - otherwise, no way to drill the starter hole in just one half.

Then bolted the caps onto the holders, centered up the holders in the 4-jaw (using the inside of the bore as a reference, tricky since it was only a semi-circle) to bore the caps out to match the holders.

The front side needed to be trimmed back to match the thickness of the holders, so used the expanding madrel again - the parts laying on the cross slide show the difference in thickness before trimming.

And the completed parts held up to the model - this probably would have been easier to make with the caps in the first place, but it all worked out fine in the end.

The blue lines on the horn plate show where a slot needs to be cut so the crankshaft can be lowered into place - the original machine has this slot. The other axles can be slid into place through the holders with the bearings removed, the gears will be on keyways so they can be assembled in place.

[cnr6400]

 

Great progress Chris! One thought - that top cover screw, right at the top of the last photo - does whatever it threads into under the cover clear the crank drop slot?

 Of course if the securing bits it threads into did interfere with the slot, maybe the crank drop slot could be angled to the rear slightly to gently guide the crank into the main bearings, angled by the designers, for convenience in this very operation! (that's my story and I'm sticking to it) 

[crueby]

CNR, the arched steel bar that the cover screws to comes out with two screws, so the bar and top cover will come out to insert the crankshaft. I wanted that bar to be full length so the two sides would get the most support, that side panel being so structural to the transmission, especially at the model scale.


I've gotten started on drilling and tapping the holes for the bearing holders, looking like multiple setups for the lower two since the horn plates can't rotate far enough without hitting the mill column, even with the riser block for the headstock. Long plates, small mill!

[cnr6400]

The long arched steel bar sounds like a very good idea. Smart of you to make it removable for crank insertion. It's going to be a great truck.    

[samc88]

Nice work on the bearing caps

Sent from my G3121 using Tapatalk

[crueby]

Thanks guys!

More done on the bearing holders - Started with the larger ones for the crankshaft, drilled the hole patterns around the rim, skipping the ones at the ends of the wings till all the rim holes were done so I could leave the distance from center locked in.

Then mounted the horn plates, and drilled/tapped  matching holes there.

Followed by the ones out at the wing tips. The holes in the plates are tapped, so I could run screws in from the inside to make the mounting studs - will have nuts on the outside.

Then did likewise for the smaller holders for the transmission shafts:

Drilling the holes in the horn plates for these was tricker, since the plates would not rotate all the way around without hitting the mill column, so the last couple holes on each side had to be set up for again with the drill coming in at a different position.

Lastly made up the bearings themselves, these are simple bronze tubes with a small lip at one end. To allow them to be removed to facilitate putting the keyed shafts in, these bearings will not be a press fit but will have a grub screw in from the side of the holder. Could just remove the bearing holder, but there is so little space for a nut driver or a wrench, that being able to slide out the bearing is much easier. With the bearing out, there will be enough room to slide the keyed shafts in and out.

Lets see, I think that cutting the crankshaft slots at the top is the last step on the horn plates. After that is done, I should be able to clean things up, degrease the parts, and get a coat of paint on everything - frames and horn plates.
 

[tghs]

looks great, that's a lot of drilling and tapping but all the nuts give it the correct look..

[cnr6400]

You left those hornplates and a couple of bearings in a dark room alone, didn't you? The bearings have definitely multiplied! Lookin great.

 

[crueby]

looks great, that's a lot of drilling and tapping but all the nuts give it the correct look..

Finished getting all the nuts on the studs holding the bearing holders installed, quite tedious! There is not enough room for a nut driver, so had to use small needle nose pliers to hold the nuts while turning the screw from the other side to get them started.

You left those hornplates and a couple of bearings in a dark room alone, didn't you? The bearings have definitely multiplied! Lookin great.

 

What happens in the toolbox, stays in the toolbox!   

[crueby]

Nice sunny warm day outside, perfect for painting. I cleaned/degreased the parts, and set up out in the driveway to give them a coat of paint. As before I am using Duplicolor Engine Enamel, which is a ceramic-containing paint that can take high heat and wears well, but requires no oven curing. The boiler was taped off to protect the green already on it, and the cab subframe was given a coat of semigloss black while the horn plates and main frame got dark green to match the boiler.  Here is a teaser shot, with all the parts back on the bench to finish curing up.

[crueby]

A few hours to let the paint harden up, and got it all re-assembled. Wow, does it look different with color!



And one thing I was worried about was the alignment of the shaft bearings, but I was able to slip the transmission shafts in easily, a little lapping and they will run smoothly (I had left the holes in the bearings a snug fit in case they needed alignment work, but the plates seem to align well).


Next up, some time sitting and admiring, then on to..... um.... the damfino!      

[cnr6400]

 

[Kim]

I'll say!  That looks mighty sharp, Chris!   
Kim

[ddmckee54]

Chris:

Obviously, the next part on the todo list is the Turbo Encabulator.

Don