Author Topic: Chris's Marion 91 Steam Shovel  (Read 305621 times)

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3540 on: March 30, 2019, 06:51:23 PM »
Is it true that one piston or valve gland in the hand is worth four on the floor ?

(sorry, I'll get my coat on the way out.....forgot to issue the bad pun alert)
Now we know where that keg of Guinness went...   :Lol:

Offline cnr6400

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Re: Chris's Marion 91 Steam Shovel
« Reply #3541 on: March 30, 2019, 07:06:04 PM »
>urp< I resemble that remark, ossifer!  :Lol:

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3542 on: March 30, 2019, 08:06:25 PM »
Not a lot of shop time today, had to go bail out CNR...
Did get the piston glands drilled/tapped and installed. Used a nut/bolt to hold them in place for drilling. The one at upper right has the screws and o-rings installed.


I've started cutting/threading the ends on the piston rods, pics on that as it goes on...

Offline Brian Rupnow

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Re: Chris's Marion 91 Steam Shovel
« Reply #3543 on: March 30, 2019, 09:11:02 PM »
I like the way you have attached the piston rod glands. I've always done it by one external thread on the gland and a matching internal thread on the endcap. I find that with the method I have used its very difficult to keep things aligned and not put a bind on the piston rod.---Brian

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3544 on: March 30, 2019, 09:37:14 PM »
I like the way you have attached the piston rod glands. I've always done it by one external thread on the gland and a matching internal thread on the endcap. I find that with the method I have used its very difficult to keep things aligned and not put a bind on the piston rod.---Brian
I've done it this way a number of times, works nicely since the pressure on the ring is adjustable. The holes are a little larger than the piston rod so it does not rub on the metal. If it was visible at all on the finished engine (not, since the crosshead guide surrounds it) I would cut down the sides and taper the ends around the screws to make it look like a typical packing gland.

Offline derekwarner

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Re: Chris's Marion 91 Steam Shovel
« Reply #3545 on: March 31, 2019, 12:26:42 AM »
Chris....something  :Argue:....is playing tricks in my mind......I see the split shaft with each 1/2 or longitudinal section on a common axis

So why is the axis of the body of the centre bearing that covers the split shaft further toward the engine top end than the outer two bearing housings?


Or, is it just an optical illusion?  :facepalm:

Derek   :shrug:
« Last Edit: March 31, 2019, 12:38:04 AM by derekwarner_decoy »
Derek Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3546 on: March 31, 2019, 12:33:15 AM »
Chris....something  :Argue: ....is playing tricks in my mind......I see the split shaft with each 1/2 or longitudinal section on a common axis

So why is the axis of the body of the centre bearing that covers the split shaft further toward the engine top end than the outer two bearing housings?

Derek   :shrug:
Its not - remember that I hid the top cap of the center bearing to show the split. I think you are comparing the top of the cap on each end with the top of the base in the center?

Offline MJM460

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Re: Chris's Marion 91 Steam Shovel
« Reply #3547 on: March 31, 2019, 12:51:49 AM »
Hi Chris, going like a train as usual.  Well, I know it’s not a train, but “going like a shovel” just does not have the same ring to it.

By coincidence, I was at the same stage of making a single gland of the similar design yesterday.  Of course, today you are way ahead of me, but can I please ask how did you clamp that gland in place while you drilled through the stud holes to the cylinder head?  Or did you coordinate the gland flange first, then just spot the cylinder heads?

Really great progress on your part, and I am delighted to find little things that I can learn learn by watching, while I continue to be amazed by your work.

MJM460

The more I learn, the more I find that I still have to learn!

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3548 on: March 31, 2019, 02:18:23 AM »
Hi Chris, going like a train as usual.  Well, I know it’s not a train, but “going like a shovel” just does not have the same ring to it.

By coincidence, I was at the same stage of making a single gland of the similar design yesterday.  Of course, today you are way ahead of me, but can I please ask how did you clamp that gland in place while you drilled through the stud holes to the cylinder head?  Or did you coordinate the gland flange first, then just spot the cylinder heads?

Really great progress on your part, and I am delighted to find little things that I can learn learn by watching, while I continue to be amazed by your work.

MJM460
Hi MJM,
The gland has a short cylinder that fits into the hole in the plate, so that locates the holes in the two parts into one axis. I put a nut and bolt through the holes to squeeze them together like a clamp, then drilled the two screw holes with the tap drill. The gland was then counterbored out to the clearance size while still clamped together - just went down by the thickness of the gland disc.

Does that make sense? In the photo from that post, you can see the top of the hex head screws through the hole in the glands - that is through the piston rod hole.

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3549 on: March 31, 2019, 02:23:48 AM »
Hi Derek - looks like you updated your photo with the red/yellow lined box - that does not line up since you did not make the box long enough at the front. Here is another screen grab with the center bearing cap shown again:



And a top view to show they do line up:



No optical delusions needed. The ortho projections do make the eye do odd things though, since it is expecting perspective.

Offline derekwarner

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Re: Chris's Marion 91 Steam Shovel
« Reply #3550 on: March 31, 2019, 03:19:14 AM »
Thanks Chris......

As MJM notes, it is a learning curve for many [certainly me included]......but I would rather markup & place a few RED lines in question with a copy rather than just accept without understanding

Derek
Derek Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline MJM460

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Re: Chris's Marion 91 Steam Shovel
« Reply #3551 on: March 31, 2019, 03:22:24 AM »
Thanks Chris, that makes perfect sense, I missed that hex head in the middle.

I will go out this afternoon and see what I can do.

MJM460

The more I learn, the more I find that I still have to learn!

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3552 on: March 31, 2019, 12:49:04 PM »
Thanks Chris, that makes perfect sense, I missed that hex head in the middle.

I will go out this afternoon and see what I can do.

MJM460
What are you building?

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3553 on: March 31, 2019, 05:03:01 PM »
Thanks Chris......

As MJM notes, it is a learning curve for many [certainly me included]......but I would rather markup & place a few RED lines in question with a copy rather than just accept without understanding

Derek
No problem at all, ask away anytime anything is unclear.   :cheers:

Offline crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #3554 on: March 31, 2019, 05:09:13 PM »
Got the pistons made up this morning, started with threading the bottom end of the piston rods to attach to the crossheads, and a short thread at the top for the pistons. A shoulder was turned in for the piston head, so the nut at the top will compress it onto the shoulder and square to the rod. When all else is ready for assembly, a little loctite will go onto that end of the rod to retain the piston.

The piston heads were turned up as a group, the OD slightly smaller than the bore so the O-ring can form the seal. The rod was notched to form 1/4" thick pistons, then one at a time grooved for the o-ring until it was a nice sliding fit in the cylinder, then the piece was parted off and repeat on the next.

Assembled pistons:

They all seal well, so on to the next steps. Which are... um, think the valve levers would be good to do next.