Author Topic: Chris's Mann Wagon Build  (Read 130084 times)

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1035 on: November 21, 2020, 08:55:38 PM »
And wrapping up work on the connecting rods. Made the simple press-fit tube bearings for the little ends from bronze, and then shaped the big end bearings from some larger bronze rod. They have flanges on either side to keep the con-rods centered on the crank pins. The centers were drilled to be a snug fit.


Then used a fine bladed jewelers saw to slit the bearings lengthwise and parted them off from the bar.

They were then assembled to the con-rods, loctited in place to keep them from spinning.

Finally used some green Timesavers lapping powder mixed with oil to lap them to the crank pins for a smooth turning fit. Here they are after another dis-assembly to clean out the lapping compound and ready to move on to making the eccentric followers.


Offline pgp001

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Re: Chris's Mann Wagon Build
« Reply #1036 on: November 21, 2020, 11:45:59 PM »
Chris

How are you planning on holding the big end caps to the rods ?
It looks like you will nip the journal if you tighten up those screws too much. Maybe studs and lock nuts ?
Have you pinned the bushes to prevent them rotating in the rod.

Phil

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1037 on: November 22, 2020, 12:12:32 AM »
Chris

How are you planning on holding the big end caps to the rods ?
It looks like you will nip the journal if you tighten up those screws too much. Maybe studs and lock nuts ?
Have you pinned the bushes to prevent them rotating in the rod.

Phil
Hi Phil,


The caps are held on by the screws. The shcs's will be replaced with studs and nuts. The bearing halves are loctited to the caps and rod ends to keep them from rotating. Pins would be tough on such small parts.  Not sure what you mean by nipping the journal, the caps cannot touch them, and the bearings are lapped to the journal. The gap from cutting the bearings is very narrow, blade used is only .010 thick, and a couple thou was removed when lapping. Even with the screws snug, the rods still rotate. The second one o last photo makes the gap look big, but the screws were no where near tight in that shot, just run in to keep the caps from getting mixed up.




Edit: on second look I think I see what you mean, to keep the nuts from vibrating loose? I usually put on a drop of blue loctite on them so they stay but can be adjusted.
« Last Edit: November 22, 2020, 12:17:04 AM by crueby »

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1038 on: November 22, 2020, 10:18:25 PM »
Starting in on the eccentric followers. The end around the eccentrics will be bearing bronze, with steel arms added to go up to the reverse links. Started with a length of 1.5" round bar long enough to make 5 followers (one spare in case of goof up). It was sawn lengthwise in half, the sawn faces smoothed in the mill, and notches milled in on each side for the screw tabs. Then drilled/tapped for a pair of screws for each follower. The top half was clearance drilled, bottom half tap drilled.

Tapped all the holes, bolted the halves together, and centered it up in the 4-jaw to bore the center out. This hole was done to the OD of the slots in the eccentrics, since that is the smallest dimension. Later on the outer edges of each follower will be counterbored out larger to match the OD of the eccentrics, leaving a tab sticking out in the center to ride in the slot.

Then parted off the individual followers, leaving them thick.

Last step for the day was to get out an expanding arbor that I had made for a previous project, and turn the end to fit the followers. This arbor is sawn down most of its length, 90 degrees apart, and also drilled/tapped down the length for a SHCS. That screw had the head tapered slightly so it would go into the hole in the end more easily and spread the fingers. The end of the arbor hole was drilled out larger, to the size of the narrow end of the taper on the screw. So, the part can be put on the end of the arbor, up against the shoulder in the end, and the screw tightened to expand the fingers, gripping on the part like a reverse collet - very handy tool!
Took a facing cut on one side of each part, down to just outside the width of the screw heads holding the halves together. Then flipped the parts around, and faced off the other side down to final thickness.

Next time, will cut the counterbore in each side of the holes to leave the tab in the center...

Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1039 on: November 23, 2020, 12:14:31 AM »
You didn't slice a loaf of bread for sandwiches yesterday did you Chris, and got inspired? Only that loaf of followers and the individual slices look mighty familiar........... :thinking:   :Lol:

In my shop the loaf would probably be called Blunder Bread these days rather than Wonder Bread!   :Lol:

Just kidding around, the parts and tooling look excellent as usual.   :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1040 on: November 23, 2020, 01:06:37 AM »
You didn't slice a loaf of bread for sandwiches yesterday did you Chris, and got inspired? Only that loaf of followers and the individual slices look mighty familiar........... :thinking:   :Lol:

In my shop the loaf would probably be called Blunder Bread these days rather than Wonder Bread!   :Lol:

Just kidding around, the parts and tooling look excellent as usual.   :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Now I'm hungry!   :Lol:   Good thing I've got a couple loaves of excellent italian bread in the fridge, time to go slice one up!  Will taste a lot better than the bronze.

Offline Don1966

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Re: Chris's Mann Wagon Build
« Reply #1041 on: November 23, 2020, 01:30:08 AM »
Awwwww my hero......... :ThumbsUp:



 :drinking-41:
Don

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1042 on: November 23, 2020, 01:38:35 AM »
Awwwww my hero......... :ThumbsUp:



 :drinking-41:
Don
For the parts or the bread?!    :ROFL:   


 :cheers:

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1043 on: November 23, 2020, 08:43:56 PM »
Today got the eccentric followers fit to the eccentrics. Yesterday had turned the ID to fit the slots, today cut the recesses on either side to fit the OD of the eccentrics outside the slots. The expanding arbor screw had to be recessed a little farther to get the boring bar in, then it was a matter of taking a cut either side of the part.

Those cuts left this ridge inside the hole in the followers:

which fits into the slots in the eccentrics:

Here all four had been fit.


Next will be to finish shaping the outsides of the followers. This one has the shape sketched on to show where I am going with it. The cap gets narrowed down, the other side will get notched to take the arm and the profile blended in to that.


Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1044 on: November 23, 2020, 08:59:34 PM »
Hi Chris. just a thought before cutting the waste away - how do you you plan to oil the followers on the eccentrics? You could form an "oil box" out of the waste area either at the back end or next to the rods. This could have a small drilled hole to seep oil into the follower groove / eccentric od.  :thinking: :headscratch:

the fitting work looks great!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1045 on: November 23, 2020, 09:05:21 PM »
Hi Chris. just a thought before cutting the waste away - how do you you plan to oil the followers on the eccentrics? You could form an "oil box" out of the waste area either at the back end or next to the rods. This could have a small drilled hole to seep oil into the follower groove / eccentric od.  :thinking: :headscratch:

the fitting work looks great!  :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
Oooh, interesting idea! Something like this? Could put a small hole down through, with a wider 'cup' at the opening. I like it! Send that guy a cookie, elves!   ....  uh oh, they already ate it. There is an empty box on the way....  :facepalm2:


Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1046 on: November 23, 2020, 10:44:13 PM »
Your sketch on the follower was exactly the kind of thing I had in mind. Whether it is at the front near the rod as shown, or at the back end, would depend if one area was more accessible for a squirt of oil than the other, without moving covers. Good luck with the oil boxes.

Speaking of boxes - re empty cookie box arriving shortly  - no worries - I'm just glad a usable idea popped out of the wood block on my shoulders. :Lol:

Oddly though -  we are getting used to empty boxes by mail, on items from China.  :o

 I guess someone in the delivery chain from China to here does a little early Christmas shopping. :cussing: :cussing: :cussing: It has happened 3 times in the last two months.
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1047 on: November 23, 2020, 11:02:50 PM »
The front side above the rod might make it accessible to a needle oile through the opening in the front cover, have to test. Worst case is two screws to pop the top cover off.


 :cheers:


Now, time to whip up some batches of Christmas cookie dough...   :P

Offline cnr6400

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Re: Chris's Mann Wagon Build
« Reply #1048 on: November 24, 2020, 01:30:19 PM »
Now you made me hungry!  :Lol:  Not shortbread's, by any chance?
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Mann Wagon Build
« Reply #1049 on: November 24, 2020, 01:53:15 PM »
Now you made me hungry!  :Lol:  Not shortbread's, by any chance?
Sugar cookies with lemon, rolled out for cookie cutters, iced with colored sprinkles. Old family tradition. Yummy!

 

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