Author Topic: Stuart No 1  (Read 16108 times)

Online Jo

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Re: Stuart No 1
« Reply #135 on: February 10, 2019, 11:32:14 AM »
Thanks Guys I am pleased you are following along  :)

I decided that I should start on the rest of the valve gear which are all castings  :whoohoo: There was a mark on the valve which required a quick fix then off we go.

Starting on the eccentric the first requirement is the turn up the holding spigot, then this can be used to turn the outside of the eccentric and one side of the "step". The end of the boss also needs turning flat so that it can then be marked for the bore and centre punched.

Mounting the eccentric up in the four jaw and centring on the punch mark the outside of the boss can be turned, it can be taken to length and bored.

I would have turned the other side of the eccentric in a collet but I had forgotten about the depth of the boss so it did not fit  :facepalm: Thankfully Mr Silky's three jaw chuck is accurate so I used that to hold the eccentric.

The last requirement is to drill and tap for the grub screw and to check it fits on the crankshaft. This is now available to let me turn up the strap which is a really fun casting to machine   :naughty:

Jo
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Online Jo

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Re: Stuart No 1
« Reply #136 on: February 10, 2019, 04:07:42 PM »
The eccentric strap has already been started so I have to keep within its features  :-\ First up is to make sure the clamping face was flat and then to drill and counter bore for the two bolts to hold the two halves together.

I find drawing a circle on the strap useful for setting it up in the four jaw before a quick facing cut then boring to fit the eccentric and cutting the groove using a grooving tool  :naughty: The other side can be faced by clamping round a piece of bar held in the three jaw chuck.

The outside was rounded using the BCA and at the same time I milled the slot for the arm and drilled for the two mounting bolts. A quick mill down either side to check the two outer surfaces are level and the shape is finished with a hand file.

Surus' model engine casting collection building plan shows that this engine should take two months and we are not half way through the planned construction time.....he is going to see this as an opportunity to justify buying him more castings  :facepalm:


Eric  :Director:   Where's those pics of your crankshaft your were promising  :stickpoke:

Jo

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Offline b.lindsey

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Re: Stuart No 1
« Reply #137 on: February 10, 2019, 04:20:43 PM »
There shouldn't be too much left Jo. Not surprising that you are well ahead of schedule. Looking forward to seeing it run.

Bill

Online Jo

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Re: Stuart No 1
« Reply #138 on: February 10, 2019, 07:01:39 PM »
All the remaining bits are sitting in front of the engine Bill, except the studs  :facepalm: and their nuts  ::)

Jo

P.S. Eric we are still waiting :stickpoke: 
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Offline steam guy willy

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Re: Stuart No 1
« Reply #139 on: February 10, 2019, 07:47:42 PM »
hi Jo  possibly lots of studs with their nuts watching !!!  What is the paint colour btw

 :popcorn: :popcorn:

wily

Offline kev

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Re: Stuart No 1
« Reply #140 on: February 10, 2019, 11:45:11 PM »
love the internal grooving tool Jo, any info on it?

Online Jo

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Re: Stuart No 1
« Reply #141 on: February 11, 2019, 07:21:20 AM »
Hi Kev, sorry no I acquired it in a box of boring bar tools  :-\



Eric waited until late yesterday to send me through his pics.

He carefully turned up a jig to do his crank web turning on and has got as far as loctiting the crank.

Jo
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Online Jo

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Re: Stuart No 1
« Reply #142 on: February 11, 2019, 05:30:25 PM »
This casting set did not come with the valve arms so I am using a spare one from the No 5s.

The first job is to mill it flat and drill/tap for the bolts. Then the two sides were tapered and the ends rounded over using buttons screwed into the threaded holes in the arm.

The last bit of machining was the slot. Then it was just a case of giving it a little polish before checking the fit.

I am going to have to start working on the fixings at some point, those temporary screws look  :facepalm:

Jo
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Offline bent

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Re: Stuart No 1
« Reply #143 on: February 11, 2019, 06:06:47 PM »
Wow, you are a speedy machinist Jo!

A question, any reason besides esthetics to machine the backside of the valve eccentric "square" (vs. leaving the as-cast radius)?  Also, no paint on the cylinder/valve chest - is that because there are exposed internal passages?

Online Jo

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Re: Stuart No 1
« Reply #144 on: February 11, 2019, 06:16:16 PM »
Thanks bent,

The eccentric could have been machined with a radius but may have looked a little lopsided as it went round.

The cylinder is due to be clad and I have not yet decided if I am going to paint the chest... The cladding is blued steel which might look better with a CI chest. Which reminds me Eric has the Blued Steel  :thinking:


Update from Eric he has been shopping rather than making swarf :hellno:

Jo

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Online Jo

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Re: Stuart No 1
« Reply #145 on: February 11, 2019, 09:41:45 PM »
Clearly my earlier comment worked  :naughty: as Eric has been out doing a bit more on his engine. He has split the crank and has the bearings in place  :ThumbsUp:

Jo
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Offline b.lindsey

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Re: Stuart No 1
« Reply #146 on: February 11, 2019, 10:29:54 PM »
Nice work on both engines.

Bill

Offline ChuckKey

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Re: Stuart No 1
« Reply #147 on: February 12, 2019, 09:18:05 AM »
Would I be right in thinking there is a little procrastination going on over the support column?

Online Jo

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Re: Stuart No 1
« Reply #148 on: February 12, 2019, 09:23:25 AM »
No.

The agreement is that we do the support columns once we know that everything else lines up and goes round and round smoothly as any position adjustment on anything else alters the required length of the rod and the position of the hole on the bottom cover or the stud holes on the sole plate  ;)

Jo
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Offline Stuart

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Re: Stuart No 1
« Reply #149 on: February 12, 2019, 11:10:02 AM »
Looking good there Jo

Great pics and narration

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