Author Topic: Stuart No 1  (Read 30498 times)

Offline Jo

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Re: Stuart No 1
« Reply #45 on: January 25, 2019, 09:52:31 AM »
The earlier drawing (and Andrew Smith's book) has the split piston. Both drawing sets allow for the nut so I may as well add one to prevent the piston moving.

The other interesting thing is the earlier drawing has the 8.73mm diameter rod and a 9.1mm hole in the cover whereas the later on an 8mm rod and a 8mm hole, which is probably asking for trouble  :thinking:

My rod is 8.73mm diameter, so I will probably go for 9mm hole. Work time  :whoohoo:

Jo
Enjoyment is more important than achievement.

Offline Jasonb

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Re: Stuart No 1
« Reply #46 on: January 25, 2019, 01:16:51 PM »
Yes I think a locknut is the way to go.

Not sure if I would tap both piston halves, maybe only part tap the top half and have the rest and all the lower one a good fit on the reduced diameter end of the rod so they register on that.

Offline Jo

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Re: Stuart No 1
« Reply #47 on: January 25, 2019, 01:38:49 PM »
I'll be back on the piston rod and piston shortly JB ;)

In the meantime I have finished turning up the bottom cover. It shows the mount being offset by 9.53mm from the turned surface but it does not show an angled surface for the nut to tighten on to  :headscratch: So I have left it at 6.35mm wide for now.

Using the chucking piece the cover can be located easily on the zero datum on Tgs  :naughty: then I just had to check that the stand would be in the centre of the arm before drilling all the holes. Repeat for the other cover and we can try it on the stand  :)


Eric is promising me more pics but he is currently celebrating selling is Disco and thinking what casting sets he should spend the money on  :-X

Jo
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Offline b.lindsey

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Re: Stuart No 1
« Reply #48 on: January 25, 2019, 02:45:59 PM »
You must be getting lots of shop time in Jo. This one is coming along rapidly and really taking shape.

Bill

Offline Jo

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Re: Stuart No 1
« Reply #49 on: January 25, 2019, 05:56:40 PM »
Its Winter Bill and its cold outside playing in the garden and the workshop is nice and warm  :)  Sorry no more this afternoon I have been at the village Sewing Bee with the other ladies  :embarassed:

Jo
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Offline b.lindsey

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Re: Stuart No 1
« Reply #50 on: January 25, 2019, 10:02:16 PM »
Do they inquire as to your modeling interests?

Bill

Offline Stuart

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Re: Stuart No 1
« Reply #51 on: January 26, 2019, 07:33:09 AM »
I bet they have Jo sussed out to repair there sewing machine  :stir:

Stuart
My aim is for a accurate part with a good finish

Offline Jo

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Re: Stuart No 1
« Reply #52 on: January 26, 2019, 07:45:53 AM »
Do they inquire as to your modeling interests?

Bill

We discuss everything, its the hive of village gossip  ::)

Jo
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Offline Jo

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Re: Stuart No 1
« Reply #53 on: January 26, 2019, 09:17:10 AM »
A quick bit of preparation for machining the port face before some gardening  :D

I decided that the easiest way to hold the cylinder was in the little vice which needs the roller skate to move it  ::)

I started dialling in the jaws (standard technique zero on the centre, wind to the outside undo the top table rotate vice so it measures zero, retighten = job done) to find it was not working right  :headscratch: Further exploration showed the finger was sticky on Tgs gauge  :facepalm: so that has been oiked off and needs servicing, thankfully my Supplier sold me another a couple of weeks ago.

Just need to mount up the cylinder and we are off  :cartwheel:

Jo
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Offline Admiral_dk

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Re: Stuart No 1
« Reply #54 on: January 26, 2019, 04:58:11 PM »
That is a drag (pun intended) Jo. I hope this isn't going to prevent you from making more swarf engine parts for too long  :ThumbsUp:

Offline Jo

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Re: Stuart No 1
« Reply #55 on: January 26, 2019, 05:13:34 PM »
We are ok Per, I have a spare  ;)

Normally I use a level on top of the port face to make sure things are level but the draw on the casting means that face is shaped like a tent so It was necessary to use a square on the side of the valve face instead.

Now we can face it down to 6.35mm, mill the side of the port face square, on one side dropping down to square up the exhaust face. The ports measured up equally spaced from the top and bottom edges  :ThumbsUp:

I will wait until later tomorrow morning to continue ....

Jo
Enjoyment is more important than achievement.

Offline Laurentic

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Re: Stuart No 1
« Reply #56 on: January 26, 2019, 10:48:18 PM »
Nice work so far Jo, have come on this late in the day.  Will watch on.

Back to your day one and I'm not surprised you bit Station Road Steams hand off at £195 for the casting set - just checked price for a set from the manufacturers for a No.1 and it's £482 + VAT (+20% extra for the benefit of our overseas friends) - ouch!  Too much for me at that price.

Chris
« Last Edit: January 27, 2019, 12:05:36 PM by Laurentic »

ChuckKey

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Re: Stuart No 1
« Reply #57 on: January 27, 2019, 10:06:40 AM »
We are ok Per, I have a spare  ;)

Normally I use a level on top of the port face to make sure things are level but the draw on the casting means that face is shaped like a tent so It was necessary to use a square on the side of the valve face instead.


Jo, the portface, where you have the level, is the last surface I would use for setting that job up. It is going to be machined, so it does not matter where it is. Surfaces that are going to remain unmachined matter the most in setting up a casting. There are two things I would measure. The less important, which you have ended up using, is the squareness of the sides of the port block (or whatever it is called). As far as I can see, the most important thing is to ensure that the finished unmachined sides of the port block are equidistant from the centreline of the cylinder. This would be measured each side by working from the already machined end flanges.

Offline Jo

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Re: Stuart No 1
« Reply #58 on: January 27, 2019, 11:16:45 AM »
Hi Chuckkey :- The port face was only 0.8mm over width before machining. So choosing where the port face is as much aesthetic (seeing what the casting will allow) as seeking ultimate accuracy and risking having to make the entire port face narrower.



Eric has provided another set of pics  :) His covers don't have any chucking piece  :headscratch:

I better get out in my workshop he is racing ahead on his engine :o

Jo
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Offline Jo

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Re: Stuart No 1
« Reply #59 on: January 27, 2019, 03:54:53 PM »
Back to my cylinder  :)

The ports look to be nicely central to the port face. I was a little concerned that the cutter was being pushed side wards while milling the first slot but it is just a figment of the lighting conditions  ::) Even the inlet ports lined up nicely. Allowing me to first mark to check the positions and then drill for the steam chest studs.

I decided I would prefer the drain cocks opposite the steam chest so the cylinder was mounted on the valve face, the centre found and the drain cock holes drilled. The Pillar tool was used to make sure that all the threads went in square.

The covers even fitted... next I need to think about the crosshead and mounting the cylinder on the standard  :thinking:

Jo

Enjoyment is more important than achievement.

 

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