Author Topic: Stuart No 1  (Read 12597 times)

Offline b.lindsey

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Re: Stuart No 1
« Reply #60 on: January 27, 2019, 04:45:14 PM »
Still coming Al ng well Jo. I also like that shorter lift table you have for that monster vise😊

Bill

Online Jo

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Re: Stuart No 1
« Reply #61 on: January 28, 2019, 08:11:21 PM »
Thanks Bill,

I had visitors again today which cut into the swarf making time  ::)

I did mark up and drill the top of the standard and clean up some of the edges. I can now check the dimensions from the sliding surface of the standard to the centre lines of the cylinder ready to machine up the crosshead.

Jo
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Offline crueby

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Re: Stuart No 1
« Reply #62 on: January 28, 2019, 08:13:19 PM »
Coming along great!

 :popcorn: :popcorn: :popcorn:

Offline bent

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Re: Stuart No 1
« Reply #63 on: January 28, 2019, 08:49:24 PM »
Great progress, Jo.  Curious as to how the conrod slide lines up relative to cylinder axis - I assume they will be parallel, though the last image it looks as if not (or not yet?).

Online Jo

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Re: Stuart No 1
« Reply #64 on: January 28, 2019, 08:53:47 PM »
Thanks Chris & Bent,

The sliding surface for the crosshead is square to the cylinder, the back edge of the casting behind the sliding surface is at an angle... like along the bottom edge. I could machine the back edge square but it is only cosmetic :noidea:

Jo
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Online Jo

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Re: Stuart No 1
« Reply #65 on: January 29, 2019, 03:15:54 PM »
A quick measurement having poked a piece of 14.3mm brass in the gland hole and remembered it was a piece of 14.3mm not 16mm when doing the calculations  :facepalm: showed that we can go by the drawing dimensions for the crosshead  :)

The piston rod/cross head was set up in the indexing head with tailstock support and the side squared up using a square against the bed. Having skimmed both sides this gave me the cutter height for further cuts and I found that there was not a lot to come off. Having taken the sides of the sliding face to width the cutter could then be raised and the sliding face itself cut at the required height and checked using the Standard before we go further.

Having taken both sides down to the 14.3mm width I could then mill the back face to 9.53mm from the centre line. The drawing shows that the top of the crosshead sliding face is 12.7mm up from the centre line of the pivot hole so that was faced next and used as a reference to find, drill and ream the hole for the pivot pin. The two curves were machined last leaving a little hand finishing.

The bottom face will be done by Mr Silky when I get back there in the meantime I decided to try the fit  :D And decided that deserved a Jaffa Cake.

Jo

P.S. John so you don't feel left out I have just eaten the two you didn't have time for yesterday as well as my two  :naughty:


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Offline steamer

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Re: Stuart No 1
« Reply #66 on: January 29, 2019, 05:21:42 PM »
Thats moving along fast Jo!  I got distracted by shiney things last night but hope to get going on my stuff tonight...
Dave
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Damned ijjit!

Offline bent

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Re: Stuart No 1
« Reply #67 on: January 29, 2019, 07:30:06 PM »
Yup, see it now.  Thanks for the last photo Jo, either some camera distortion or the angle on the back of the slide was throwing me off.  Looking good, I must say.

Online Jo

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Re: Stuart No 1
« Reply #68 on: January 31, 2019, 12:58:19 PM »
Thanks Guys  :)

The two keeper bars are not a standard size. They need to be 1.6mm thick and 9.53mm wide, the only stuff available is 12.7mm wide so 3.18mm needs to come off. Of course the wider stuff has rounded corners so we need to take off 1.6mm from both sides, which means it must be mounted parallelly in a vice. To do this I used two pieces of tool steel one on either side to tap the metal down into the vice. Then zero on the top and mill 1.6mm off, turn over and repeat twice on each piece of metal.

A good test for how parallel the metal was when machined is if it can be clamped in the vice jaws and drilled without one end pushing away from the drill bit.

Six studs knocked up - note these are real studs as you can see that there is no threads next to the standard, not bits of threaded rod poked in the holes :hellno: they are screwed in all the way and it is that threadless bit that stops them turning in any further, when adding the nuts.

The fit is nice and tight and the piston rod looks to be nice and central in its hole in the cover :cartwheel:

Jo


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Online Jo

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Re: Stuart No 1
« Reply #69 on: January 31, 2019, 04:16:26 PM »
To finish off this bit I thought I should turn up the gland as well. The round bit of the casting was given a little fettle then held in a ER collet from the tailstock to enable it to be super glued onto a bit of scrap-binium held in a collet.

With a bit of tailstock support (in case the glue gives way as it is rather cold over here  ::) ) the outside is turned to fit the lower cylinder cover and then the main flange faced. This now gives the datum to be able to turn the round bit to length. The centre was drilled and then reamed to fit the piston rod. The gland is countersunk with a 120 degree countersink, this gives a shallower cone than if I had used a normal countersink leaving more bearing surface.

The gland can now be turned round and held on the diameter to face the bottom face. The casting was not excessively thick  ::) Using the same collet in a 5C block the stud holes can be drilled. Which are then used to screw the gland onto the cover so the outside can be filed to shape.

I really need to do the connecting rod next so some round and round testing can be done  :thinking: I wonder what Eric has done on his engine   :stickpoke:

Jo

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Online Jo

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Re: Stuart No 1
« Reply #70 on: January 31, 2019, 05:23:08 PM »
Some pics from Eric. He has done his bottom cover  8)

Jo
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Offline b.lindsey

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Re: Stuart No 1
« Reply #71 on: January 31, 2019, 06:50:55 PM »
Nice progress from you and Eric both Jo.

Bill

Offline Bluechip

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Re: Stuart No 1
« Reply #72 on: January 31, 2019, 07:40:45 PM »
Nice progress from you and Eric both Jo.

Bill

Very true Bill. Good progress indeed.  :ThumbsUp:

Must be nice to have a workshop that's a bit above -3oC    :shrug:  :old:

Dave


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Re: Stuart No 1
« Reply #73 on: January 31, 2019, 07:47:38 PM »
Thanks Bill and Dave.

Must be nice to have a workshop that's a bit above -3oC    :shrug:  :old:

Dave

Dave have you thought you could put a heater on in your workshop   :) Part of my retirement planning was to allow to have an extra night storage heater running in the workshop every day in the winter. Its eye wateringly expensive almost 30p a day to be warm enough to use the workshop :disappointed: but the sun has been out so the extra power generation this week has more than paid for it.

Jo
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Offline Bluechip

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Re: Stuart No 1
« Reply #74 on: January 31, 2019, 08:18:57 PM »

Dave have you thought you could put a heater on in your workshop   :)


Got one. A 3kW fan heater  :headscratch:  It might well heat the fan but as far as I can tell it does 9/10ths of bugger all to heat anything else.  :rant:

My present strategy is to skulk in the house consuming coffee with ever-increasing sloshes of Rum.

Life eventually gets fairly tolerable.  ;D

Can't imagine how the US folks are faring with their Polar Vortex. @ -30o:thinking:

My entire day is taken up by whingeing and snivelling @ -3o:D

Dave