Author Topic: Chris's Marion 91 Steam Shovel (Read 600262 times)

crueby · « **Reply #3165 on:** February 12, 2019, 07:48:27 PM »

With all of the chain drilling repeated on all three engine blocks, was time to start milling out the remaining webs:

Took them down in a couple of layers....

Till it got down as far as the medium sized cutter would go. I'll go back with a 3/8" diameter one to clean up the bottom and take the sides down to final dimension.

With the bulk of the metal removed with the drill, the milling is going pretty quickly. The holes also gave a place for the chips to go, so I didn't have to stop too often to dump them out. One down, two more to get to this stage...

crueby · « **Reply #3166 on:** February 13, 2019, 12:25:30 AM »

The other two are to the same point, center of the crankshaft bay hogged out and ready to take to final dimensions with larger end mill... More tomorrow...

crueby · « **Reply #3167 on:** February 13, 2019, 04:24:12 PM »

This morning saw the crankshaft bays taken down to final dimensions all the way down...

On the final parts, the back inside corners will be a small radius, but the small end mill will not reach all the way down until the wall is taken down short. I am leaving the back wall tall for clamping purposes until the crosshead guides are complete.
Here they are with the crankshafts, for a small family shot.

Ye-Ole Steam Dude · « **Reply #3168 on:** February 13, 2019, 04:56:54 PM »

Hello Chris,

That is looking really good.

Have a great day,
Thomas

cnr6400 · « **Reply #3169 on:** February 13, 2019, 08:34:38 PM »

They look great Chris, well done!

Now you've got three places to toss all those small nuts and bolts!

crueby · « **Reply #3170 on:** February 13, 2019, 09:03:04 PM »

Quote from: cnr6400 on February 13, 2019, 08:34:38 PM

They look great Chris, well done!

Now you've got three places to toss all those small nuts and bolts!

I never knew it so much work to make a parts bin!

crueby · « **Reply #3171 on:** February 13, 2019, 10:26:11 PM »

Some more progress on the engine bases this afternoon, laid out and center drilled

then drilled

all the starter holes for the crosshead guides in the blocks. I put the blocks in at the back right corner of the mill vise, so I could repeat the position in the vise for all the holes. The drill is several sizes smaller than the finished bore, so I am not worried about any wander in the length of the holes, that will be brought back in by the boring head.

Here are the blocks all drilled:

Got a start on boring the first hole out to size - found that I needed to grind a bit back on the shank of the boring bar to get the depth needed for the block, but there is plenty sticking out of the holder.

Enough for one day, more on this tomorrow....

Don1966 · « **Reply #3172 on:** February 13, 2019, 10:34:47 PM »

Impressive so you decided to make it out of one piece. Waiting to see how that works out with the round overs.

Don

crueby · « **Reply #3173 on:** February 13, 2019, 11:27:41 PM »

Quote from: Don1966 on February 13, 2019, 10:34:47 PM

Impressive so you decided to make it out of one piece. Waiting to see how that works out with the round overs.

Don

Me too! The rounding at the front where the cylinders attach will be done with the rotary table horizontal on the mill, holding the block with the four jaw by the walls around the crankshaft bay. That part should be straightforward. The top features will be next, recessing them into the flat top. There is only a small roundover from there on the sides. The front of the bay wall will be tricky. I think it will all work, all the same tricky spits would be there even if pieced up. Time will tell!

crueby · « **Reply #3174 on:** February 14, 2019, 08:41:07 PM »

Halfway through boring the holes for the crosshead guides:

Once they are done, I need to drill a hole matching each in the back wall of the crank bay, to counterbore the back .100" of each hole out another .100 wider - It appears they did that for con rod clearance. The back end of the base plate sticks up higher there, but it looks like the cutting edge of the boring tool can reach around that. So far so good....

steamboatmodel · « **Reply #3175 on:** February 14, 2019, 10:54:36 PM »

Chris,
You are in an alternate Dimension, I have proof
" Re: Chris's Marion 91 Steam Shovel
« Reply #3174 on: Today at 08:41:07 PM »"
This was copied at 5;53 PM
Gerald.
PS it must be the form that is "Today at 10:54:36 PM »"
PPs I know forum runs on GMT

crueby · « **Reply #3176 on:** February 15, 2019, 12:55:03 AM »

Quote from: steamboatmodel on February 14, 2019, 10:54:36 PM

Chris,
You are in an alternate Dimension, I have proof
" Re: Chris's Marion 91 Steam Shovel
« Reply #3174 on: Today at 08:41:07 PM »"
This was copied at 5;53 PM
Gerald.
PS it must be the form that is "Today at 10:54:36 PM »"
PPs I know forum runs on GMT

Well, I am in the better universe with more hours per day....!

Works great except for jury duty.

If you go into your forum profile there is a setting for the time zone, you can set how many hours from GMT you are and it adjusts the timestamps for you.

crueby · « **Reply #3177 on:** February 15, 2019, 11:50:42 PM »

This afternoon saw the rest of the crosshead guide passages bored out to size - still want to lap them smoother on the inside, but before I do that I am going to do the shallow counterbore at the back of the openings, where they go into the crank bay. I think this is for conrod clearance on the original. To start, I have drilled and bored some 0.439" holes in the back walls, lined up with the bores. This is the largest hole I can put there without cutting into the final top of the wall after it is cut down later on, but it is large enough so that a boring cutter with a larger head on it can reach through and do the counterbores (bores are .525", counterbores are .625" diameter).

Good place to stop for the day, should be doing the counterbores tomorrow. After that they can be lapped, and start on the next phase of the shaping.

cnr6400 · « **Reply #3178 on:** February 16, 2019, 12:21:09 AM »

Looking good Chris!

10KPete · « **Reply #3179 on:** February 16, 2019, 12:36:37 AM »

I must continually remind myself that those parts are.....TINY! Well, maybe not GB tiny....

Pete

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Author Topic: Chris's Marion 91 Steam Shovel (Read 600262 times)