Author Topic: Chris's Holly Pumping Engine Build  (Read 154205 times)

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #150 on: March 28, 2021, 09:05:30 PM »
Just a thought Chris - Could you glue a block onto the base of the jig temporarily to register against the first end cut of each frame? If you cut the first frame against the block and sneak up on the length dimension for the first one, and don't move the table afterward, the other frames fitted in the jig and pushed up to the block and cut at same settings will be same length. (all of them right, or all of them wrong - don't ask me how I know that :Lol: )

You probably need to break the block's glue joint and move it for the opposite hand frames, but it could save some moves / measurement. Hope it helps. Back to my shop now! (impulse engine only today, 0 warp factor) :cheers:

PS how are the shop elves coping with the wheelbarrows of brass swarf?  :Lol:
There is a screw for the rails to register against for the tenon cuts. I removed that for the overall-length cuts since the end mill has to cover that whole face. The rails are too long to put a screw or block at the other end, and that is how I am sliding in the blanks anyway. Since the last post I have finished cutting them all to length, just needed to make an initial cut on the second end, stop and measure, and see how much farther to advance the cut to finish.

The elves are dealing with it fine so far, since it is just accumulating in the seperator next to the shop vac! Its later on when they have to backpack it all outside that the air turns blue...!

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #151 on: March 28, 2021, 09:41:19 PM »
After finishing up the trimming to overall length, with the compound angles on both ends of the rails,

I've started in on the tenon cuts. For these, there is a screw at the near end to act as a stop when putting in the rail, which will both make it easy to get the length of the cut horizontally repeatable, but it also is important for getting the depth vertically the same. Since the rails are at an angle in both directions, if one rail goes farther out from the cradle than another, it would get a different vertical amount of cutting. This way, its possible to get a repeatable placement for all four cuts on each end of the rails.

I'll go through the first cut for each rail, then set up for the second cut. Even though there are four rails in each set, there are actually only two combinations of the angles in each set, the other two can be cut the same then flipped end for end - possible since the pads at top and bottom will be both parallel and the same thickness.

Good work to send the shop elves off to the movies for, less distractions for me that way!   :Lol:   Have to see if there is a marathon Santa movie showing on... They love to heckle the workshop scenes!

Offline cnr6400

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Re: Chris's Holly Pumping Engine Build
« Reply #152 on: March 28, 2021, 10:27:08 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline Flyboy Jim

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Re: Chris's Holly Pumping Engine Build
« Reply #153 on: March 29, 2021, 02:51:25 AM »
Looking Good Chris.

Once you master tenons, you can then start cutting dovetails in brass.  :lolb:

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #154 on: March 29, 2021, 03:09:06 AM »
Looking Good Chris.

Once you master tenons, you can then start cutting dovetails in brass.  :lolb:

Jim


I've done sliding dovetails in Cherry and Mahogany. The chisels are tough to get through brass though!

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #155 on: March 29, 2021, 05:39:37 PM »
Continued on with milling the sides of the tenons....

till both sides were done at each end of all the rails

Now have set the jig vertically to start on the other sides, same basic setup and moves, half have a shim under the right end, rest have a shim under the left end, and half will be done with the jig in this position, rest with the jig flipped over to other angle.

So far so good, the third side has lined up with the ends of the other two...

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #156 on: March 29, 2021, 09:59:50 PM »
A few more shop sessions this afternoon, got the rest of the tenons cut on the lower frame rails:

Here is the pile of rails, ready to make the pads for the top/bottom of each that let them bolt to the bases and the engine bases up above:

They still need a little thickness trimming, the dimension in one direction is just under 1/2".  I did take a bar of 3/8" x 5/8" stock and cut it into segments for the pads - the cut depth stop on the bandsaw comes in handy for these kinds of cuts.

Um, the shop elves found the stack of pad blanks, and think that they have found my stash of gold bars. Don't have the heart to tell them its just brass, will wait till tomorrow - let them celebrate tonight!  They'll probably put on the tape of Kelly's Heroes and act out the scenes with them....


The pads will get rectangular mortise holes milled in them to take the tenons on the rails. Playing with the idea of making a little adapter plate for the broach, to do the square inside corners. Either that or file the drilled holes to square off the corners.

Online Kim

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Re: Chris's Holly Pumping Engine Build
« Reply #157 on: March 29, 2021, 10:11:32 PM »
That's a lot of frame pieces there, Chris!  And you get to do 2x the number of those end caps   :popcorn:

Pretty fun to watch you work :)

And hey - I just read my latest Live Steam mag (yeah, I'm a few weeks behind!) and really enjoyed your first Shop Elf Corner installment on nickel plating.   Great work on that too. Looking forward to reading more instalments of the shop elf corner :ThumbsUp: :)

Kim

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #158 on: March 29, 2021, 10:15:15 PM »
That's a lot of frame pieces there, Chris!  And you get to do 2x the number of those end caps   :popcorn:

Pretty fun to watch you work :)

And hey - I just read my latest Live Steam mag (yeah, I'm a few weeks behind!) and really enjoyed your first Shop Elf Corner installment on nickel plating.   Great work on that too. Looking forward to reading more instalments of the shop elf corner :ThumbsUp: :)

Kim
Thanks Kim!  Later on in the build are similar frames up between the engine bed and the cylinders, at least those are only angled in one direction, but they have all the crossheads and valve rod attachment points built into them too.

Glad you liked the article, next issue should have one on taper locks, after that will be some intermittant articles/plans on the Mann truck build. Towards the end of the year the big article on the Marion steam shovel should start....   :cheers:

Offline cnr6400

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Re: Chris's Holly Pumping Engine Build
« Reply #159 on: March 29, 2021, 10:36:25 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:

The solid gold brass frame parts are looking great!
"I've cut that stock three times, and it's still too short!"

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #160 on: March 29, 2021, 11:57:15 PM »
Well, I was not expecting that to work out so easy!  I was looking ahead a little to how I was going to make the mortises in the pads to take the rectangular tenons from the frame rails. Normally, when making a couple like that, I would just drill/mill the outline and file the corners square. But, in this case, there are 24 pads to make, four corners per, then do it again for the upper frames.... Lots of filing.


Last year I had picked up an arbor press and a small broaching set for the gears on the Mann truck. Yesterday had the idea of using the broaching cutter to do the squared corners, and figured that I would have to make a special guide to start in a narrow slot rather than the usual round hole.  This evening, to test that out, I grabbed a scrap bit of brass and drew the outline of the mortise needed, and milled a slot at either end with a 1/8" end mill.

Upon testing that with the 1/8" wide broach, it turned out that the depth of the broach worked out perfectly, I could run it through once with the slot as cut, then add the wedge to finish it off, and both wedges to do the other end of the slot. Instant (nearly) two squared corners! At most would take slight filing to get a good fit on the tenon.


In the photo, the slot on the left is as- milled, the one on the right is after broaching. All I'd need to do then is to make a couple more passes to connect the slots and leave the rectangle. Hmmmm!  This will work out perfect for making the mortises in the pads!
 :pinkelephant:

Offline gary.a.ayres

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Re: Chris's Holly Pumping Engine Build
« Reply #161 on: March 30, 2021, 12:03:08 AM »
All that glitters...

At least it's Elves that you have in your shop. They appreciate fine craftsmanship, but aren't highly motivated by gold for its own sake.

Imagine you had Dwarves, and how peeved they would be when they realised it was just brass! Different story entirely. Doesn't bear thinking about.

This is golden though. Will be great to see it coming together...

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #162 on: March 30, 2021, 12:05:53 AM »
All that glitters...

This is golden though. Will be great to see it coming together...
I'll take dumb luck any day. Many years ago I named my first boat (a small Whitehall row/sailboat)  Dumb Luck. 
Goes well with the phrase, Take It Easy, But Take It!
 :Lol:

Offline gary.a.ayres

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Re: Chris's Holly Pumping Engine Build
« Reply #163 on: March 30, 2021, 12:08:42 AM »
Aha... your reply crossed with my modification.

Dumb Luck is good. But is it luck, or perhaps something else...?

Offline crueby

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Re: Chris's Holly Pumping Engine Build
« Reply #164 on: March 30, 2021, 09:04:17 PM »
Today got a start on the lower frame end pads, making them as mentioned in yesterdays post, milling the two slots at the ends of the mortise opening, and will square the ends of the slots with the broach.

After a few sessions of milling (time out for lunch, some reading out on the front porch once it warmed up enough after the snow yesterday), got the pile of pads milled, ready for the broach.



 

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