Author Topic: Alyn Foundry Nattie  (Read 8687 times)

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #60 on: December 06, 2022, 07:21:45 PM »
Making a bit more progress now after the traumas of trying to silver solder the cast iron crank webs. I have made a completely new crankshaft with mild steel webs and stainless shafts and it runs nice and free and true in the bearings. All joints are Loctited and pinned. I have deliberately left the shafts over length until I receive the flywheels and gears and can see exactly how long they need to be.

On checking the squareness of the cylinder to the crankshaft, it was evident that the front face of the bedplate casting was not exactly parallel to the shaft, meaning that the cylinder was not square. In order to correct this, a piece of 3/8" diameter silver steel was inserted into the bearing holes, and the casting then supported vertically with the shaft resting in two V blocks and the base clamped to a 90 degree angle plate. This set-up ensured that when the front face was re-milled, it would be exactly parallel to the shaft, ensuring squareness of the cylinder to the crank.

The cylinder was originally retained in the bedplate with two grub screws on Grahams engine and this was what I did first. I had bored the locating hole for the cylinder a bit over size, as a result of which I found that, to stop the cylinder moving, the grub screws had to be tightened to the point where they were in danger of distorting the cylinder. Having looked at pictures of a full size National, I saw that the cylinder was attached through the cylinder flange with studs and nuts so I have adopted the same approach, although with only two studs as opposed to the full size engine having 4 (or possibly 5). I cannot see clearly from the photos.
« Last Edit: December 06, 2022, 07:25:19 PM by RayW »
Ray

Offline Alyn Foundry

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Re: Alyn Foundry Nattie
« Reply #61 on: December 06, 2022, 07:48:35 PM »
That’s a nice touch with the cylinder mounting studs and nuts Ray….  :ThumbsUp:

I’ve posted some video of an Otto style cylinder lubricator on the group page for you. The guys gave me a “ virtual “ tour of the Anson museum this afternoon, I saw a Campbell, Crossley and the Furnival in action.

 :cheers:  Graham.

Offline vtsteam

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Re: Alyn Foundry Nattie
« Reply #62 on: December 08, 2022, 01:57:35 AM »
I like the contrast of the blue gray sand castings and the highly finished crank and fixings. Great photos!  :popcorn:
Steve

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #63 on: January 01, 2023, 04:48:31 PM »
Good start to 2023, with the connecting rod completed and all revolving smoothly. I checked with Graham what the position of the piston should be at TDC and he told me "just before the exhaust port", so here it is.  Couldn't get it any closer! Happy New Year to all.
Ray

Offline Alyn Foundry

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Re: Alyn Foundry Nattie
« Reply #64 on: January 01, 2023, 05:39:38 PM »
Happy new year Ray.

Indeed a great start, we just need those flywheels from the foundry.

In the meantime I’m guessing you’ll be moving ahead with the shutter arrangement? Oh and then there’s that other “ top secret “ too…. ;)

 :cheers:  Graham.

Offline Roger B

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Re: Alyn Foundry Nattie
« Reply #65 on: January 01, 2023, 07:51:04 PM »
Looking good  :praise2:
Best regards

Roger

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #66 on: January 02, 2023, 04:58:43 PM »
One for Graham and Jason. Look, oiler cups!! Just hope the superglue holds.
Ray

Offline Alyn Foundry

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Re: Alyn Foundry Nattie
« Reply #67 on: January 02, 2023, 06:24:13 PM »
They look really nice Ray.   :ThumbsUp:

 :cheers:  Graham.

Offline Admiral_dk

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Re: Alyn Foundry Nattie
« Reply #68 on: January 02, 2023, 08:29:37 PM »
They look fine and as long as friction is low => no heating of the bearings - they should stay there  :ThumbsUp:

Per

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #69 on: January 02, 2023, 09:18:17 PM »
Thanks Per and Graham.  There will be no heat Per, as rhe crankshaft runs in two ball races each side and the bearing caps just hold them in place. The oil cups are just dummies.
Ray

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #70 on: January 09, 2023, 04:25:14 PM »
I have been making a bit more progress on the cylinder head and shutter and on the sideshaft. The shutter slide is still to be cut to length and a piece of metal silver soldered on the end, into which will be cut a vertical slot. An eccentric rotary pin on the end of the sideshaft will locate in this slot and push the shutter in and out, opening and closing the flame port.
The photos show the flame inlet port in the cylinder head in the open and closed positions.
Ray

Offline Alyn Foundry

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Re: Alyn Foundry Nattie
« Reply #71 on: January 10, 2023, 11:53:54 AM »
Hi Ray.

As you’re aware we’re rather preoccupied domestically here at the moment.

I shall get in touch with the foundry again to find out about the flywheels. You’re going to be needing them sharpish….

 :cheers:  Graham.

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #72 on: January 10, 2023, 06:42:20 PM »
No rush Graham. Still plenty to do before I need the flywheels. You get things sorted out at home first.
Ray

Offline RayW

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Re: Alyn Foundry Nattie
« Reply #73 on: January 13, 2023, 01:58:11 PM »
The shutter mechanism is now complete and working well. The slot in the vertical gate is 6mm wide and the driving pin is 3mm. This allows the necessary dwell of the shutter in the open position.
Ray

Offline vtsteam

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Re: Alyn Foundry Nattie
« Reply #74 on: January 13, 2023, 03:06:43 PM »
I like the yoke and pivot method for the shutter, and the dwell it produces, as you say. That's really cool. :ThumbsUp:  :ThumbsUp:

The slide looks very solid and nice. I do wonder how hard it is going to be on that pin... the slide has a fair amount of mass. But this is probably a very reasonably sped engine, and the sound and working adds to the interest. I do really like how it looks!  :ThumbsUp: :ThumbsUp:  :ThumbsUp: :ThumbsUp::popcorn:
Steve

 

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