Chris's Holly Pumping Engine Build

[crueby]

I of course can't speak from personal experience, but I've been told that Bondo and paint covers many sins things.  (You know, Bondo and paint makes me the welder I ain't.)

Since you're painting everything anyway, those small gaps would be a perfect application.

Don

In this particular case the gaps will go away once the sides of the frames are milled to thickness - they are only there due to the radius on the bar stock corners. For the models, I typically use a little JB-Kwik epoxy, easier to mix up in very small amounts, but same end effect as Bondo.
 

[crueby]

Here is the radiused corner I was talking about - this is the way the bars came, not something I added. After assembly, the faces on the top and bottom in this picture will be milled down to take the part to the final thickness, and that will get rid of the little gaps that the radius leave when the parts are together. The brass has all been stress relieved (500F in the oven for an hour) so taking a cut down the face won't cause the bars to bend like they would without the relieving.

So, this afternoon I got some time to start trimming the ends of the middle frame rails. First trimmed one end just enough to get past the rough cut end, then moved to the other end of the bars and trimmed them to length. The first one took longer, I checked the fit several times and moved the table in slightly several times - once I got a good fit between the side rails, the handwheel was zeroed so the rest could go quickly, just milled in to the zero tick. Here is one after trimming, when I was checking the fit. The cuts were done at the end of the middle bar, the end where it has the '6' marked on it.


and here are the other five. So far the numbers are not really needed, but later on they will be, when the other bracket holes and such get added - each frame has different brackets and plates mounted to it.


I did set up for trimming the angles on the top ends of the side rails, got one done before stopping for the day.

Fits well...

After all the angled ends are trimmed, the length of the side rails can be done. The bottom ends are just cut square across, larger blocks that the pad feet will be milled out of will be attached at the bottom ends.

[Don1966]

Very intuitive Dog and …….i……………likeeeeee…


 
Don

[crueby]

Very intuitive Dog and …….i……………likeeeeee…


 
Don

Thanks Don!

[crueby]

The rest of the rails have been trimmed for the angled ends, here is what one set of parts looks like sitting in the jig now:

Next step was to trimm the long side rails to final length. The bottom end is square across the bottom, so they were set up in the mill vise, with a 1-2-3 block clamped to the mill table to act as a length stop. Once the first one was nibbled to proper length, the handwheel was zeroed so the rest could go quickly.

Next up were the top horizontal rails. They were first trimmed to overall length, then I came back and started notching in the ends to form the little platform which will be used to bolt catwalk brackets to. First took off the two sides at each end (careful to keep the orientation correct so both ends matched). For these cuts, the far end of the rails were lined up with the other end of the mill vise, then a pass taken across. Lots of cuts to do both ends of all six rails, but this way it goes quick - clamp in vise, with left end aligned to vise back jaw, take a pass, on to next.


Then deepened the cut to take off the third side:

I've been looking at the rest of the frames, and there are a number of extra blocks and posts that will be added. It turns out that those extra pieces would cover the ends of the joints, so I can actually use screws with heads countersunk in to join the rails rather than pinning them, and the other blocks will cover the holes left. This will be a lot easier to do, and a pair of screws at each joint will be very secure. Looks like 4-40 SHCS would fit fine.
The next job will be to lay out and cut for the plates on the top rails - there are overhangs on the top rails that support the cylinder bases. Each piston has a different base size and bolt pattern, so each pair of rails will be different - time to start marking which is which and which side is which!

[cnr6400]

 

[crueby]

Getting more done on the engine frames. While set up with the mill vise I finished trimming the pad feet blocks to the same size, and added another cradle set to the bottom of the jig to hold them. It looks a little like the frame Dr Frankenstein used to hold his monster shop elf down with! My elves took one look, screamed, and ran off and hid.

Closeup of the new cradle, showing how it hold the block to the bottom of the frame for drilling.

Then it was on to drilling/tapping the top crossbar to the first side of the frame. I have a center drill that is 3/16" diameter, so I used that to start the holes and it also left a hole sized for some brass rod to plug over the screw head. Used a clearance then tap drill for 4-40 screws.

And the first one done...

Later on had a nice stack of hockey sticks for the elves next game...

Swapped the base rail over and started in drilling the holes on the second side of the frames. This is all working out well, takes about 15 minutes to do one joint, and it winds up all nicely aligned.

First frame up to having sides/top on. After all are to this stage I'll start on the middle rails.

Just had to set it up on top of the model to get a sense of how it will look. Getting quite tall!!

[Brian Rupnow]

Chris--I continue to watch, and marvel at how much work you do in a short time. You are doing great work, and a lot of it.---Brian

[crueby]

Great to have you along Brian!

And todays progress report is brought to you by the letter 'A'!   
The middle rails were drilled/tapped and screwed in first on one side

and then the other

After several sessions in the shop, a nice stack of capital A's ready for the pad feet to be attached:

Given the height overall and the size of the foot blocks, I am thinking it will go quicker to drill/counterdrill the holes in the feet blocks just in the mill vise, then put them in the jig and drill the holes through into the rails. The mill column is just tall enough to do the final drilling with the tap drill, if I want to do the counterbores and all then I need to switch the drill chuck out for the 3-jaw, which adds a lot of time and fussing about. So, drill the counterbore and through drill the blocks with the tap size drill in the mill vise, use that as a drill guide for the side rails, then expand the block holes out to clearance back in the vise. Overall it should go quicker though it sounds like more steps.If the mill column was just another inch or so taller...!

[cnr6400]

 

I hope the shop elves don't get any ideas about appropriating the "a" frames to build their new trestle on the garden railway. If you are listening to the shop elf banter, and hear the code word "The Fonz" it might mean the trestle build is about to start. (The Fonz was famous for his "Aaaaaaaaaa" when arriving, on the Happy Days TV show) 

(sorry  )

[crueby]

....
(sorry  )

I know you, you're not sorry, I can hear the laughing from here!   

[crueby]

More drilling and tapping time, and the pad feet blocks are bolted on (no loctite or anything on the joints yet, still need to be able to take it all apart for cutting in attachment points on the inside faces for other bracketry and the crosshead guide rails).

As you can see (just) at the bottom of the pads, they are square to the frame rails and dont sit flat on the table. They were cut a little oversize so that the bottom face of each could be taken off to the proper angle in the next step. The frame jig was bolted down square to the mill table, and the bottoms of the feet taken off square to the mill table. This ensures that the angles match up, the bottoms are all in a line, and the total height of the frame is correct - had to get out a longer dial caliper to measure the overall height, the usual 6" one would not reach.

A view looking down on the cut bottom faces:

So here is the first frame with the foot blocks cut, standing on the top of the engine beds. Five more to get to this stage, then a lot more shaping to do on the feet - end result will look more like the feet in this screen grab from the CAD model, which also shows the rest of the brackets and crosshead rails. Lots to do on the frames still!

[cnr6400]

 

Frame progress looks great!

(oh, and re the laughing - guilty as charged, m'lord...... )

[crueby]

Today got the rest of the pad feet bottom faces milled down, and started in with the shaping of the other sides of the feet. They get squared off to length/width at the bottom, and taper in to the sides of the frame rails, leaving the bosses sticking up for the mounting bolts. These are going to take a number of different setups. Started in with the width cuts at the bottom and next to the rails...

[crueby]

Next up was to get the ends of the feet to the proper angle and length. The rest of these shaping steps will be done with the feet unscrewed from the frame rails and in the mill vise, not room to get around them in the frame jig. The one laying on the mill table to right of the vise is before trimming the ends square to the bottom faces.


and after trimming the angles - both ends are square to the bottom faces, and to finished overall length.

Now to trim the sides to the angle to go between the 1/8" wide flat at the bottom to meet the width of the frame rail at the top. Used a bevel gauge to record the angle on the first on, and draw a guide line on the rest to make the setup faster.

This shows the angles cut on on the sides of the first block compared to the starting shape of the next

Small angles, but it really makes the appearance, aside from matching the originals! After the sides of all 12 blocks are trimmed, work can start on shaping the ends, which will be more complex to leave the bosses for the bolts and put in the curves to meet up with the frame rails.