Darjeeling ME Issue 4407 Corrections

[Donald MitchellParticipant @donaldmitchell68891]

Hi Engineers,

 

ME Issue 4407 Corrections

 

The nut on the bottom right of page 15 should be 1/4″ long and not 3/16″

 

The missing dimension on the nut on the top left of page 14 should be 5/32″

 

These corrections are confirmed by Raymond McMahon.

 

Donald Mitchell

Castle Douglas

Bonnie Scotland

[Donald MitchellParticipant @donaldmitchell68891]

[JasonBModerator @jasonb]

Thanks, J

[SteambuffParticipant @steambuff]

A question on the Turbo Generator Steam Valve. (Page 13)

 

It looks as if the main body is turned from a single 1/2″ dia piece (Brass), The diameter of the section to the right of the 1/2″ part is missing … Is this meant to be 3/8″ dia?

 

Also how do you bore the centre bore?

 

From left to right as drawn the bore is –

3/32″ for 1/2″ then

5/32″ for 3/16″ then

5/32×32 tapped for 5/16″ (Therefore narrower dia) then

5/32″ for 1/4″

 

Am I being stupid … but how can you get the 5/32″ dia between the tapped section and the 3/32″ section (As both are narrower? (To me a bit too small for a boring tool)

 

Also for the bush coming in from the bottom … the drawing shows the main body beind drilled for both 1/8″ and 3/32″ … which is correct.

 

Thanks

 

Dave

 

[JasonBModerator @jasonb]

The way I would interpret the drawing is that the 3/16 long bore in the centre that is drawn as 5/32 should infact be shown smaller and drilled to suit the 0.108″ dia on the end of the shaft, you will need some clearance around the 0.108 for the steam so carry the tapping drill right through. ( d bit may be better for the valve seat)the dotted lines are clearly too far apart.

 

regarding the bush, it should be bored 3/32″ all the way through and have a small locating spigot turned on the end 1/8″ dia, this to locate into a 1/8″ hole in the body to keep it in place while soldering. See the unassembled valve head drawing where the two “*” indicate silver soldering.

 

As for the body 3/8″ would seem right.

 

Oh and while we are looking at parts like this I notice all the steam unions are shown with 90deg csk holes, make sure your nipples/ferrules suit as a 60deg csk is more usual (use a centre drill)

 

Edited By JasonB on 03/07/2011 15:12:11

[SteambuffParticipant @steambuff]

Thanks for that esp the tip about the nipples/ferrules as I tend to purchase these parts.

 

I’ll see if Donald/Raymond confirm the internal bore of 0.108″ (Seems logical to me)

 

I hate the mix of Imperial and Metric . 7/64″ is 0.109375″ so why can’t this be used. (Rather that try and find a 2.74mm drill)

 

Dave

 

 

[JasonBModerator @jasonb]

No I said you need some room around the 0.108 for the steam (may have missed it in my edit) so the hole needs to be larger and the 5/32″ tapping drill will do nicely.

 

J

[SteambuffParticipant @steambuff]

Thanks Jason

 

Yes I did miss it in you edit … I replied to your unedited posting

 

5/32″ Tapping drill it is then. (Makes life a lot easier)

 

My Drawings from Blackgates should arrive next week .. so I will use them as my master.

 

This is my first build in ‘Large Scale” … so I don’t want too much metal in my scrap bin (Future project bin). I have built to 16mm/ft NG before.

 

 

Dave

 

[Donald MitchellParticipant @donaldmitchell68891]

Hi Engineers,

 

With regard to Steambuff’s queries at 14:43 on the 3rd July, after consultation with Raymond, I can confirm that JasonB’s reply at 15.03 on the 3rd July is spot on correct in all respects.

 

1. The very central section should be shown slightly smaller diameter on the drawing, tapping size for 5/32 is right.

 

2. As JasonB says.

 

3. 3/8 is correct.

 

4. JasonB’s well spotted comment regarding the steam union counersink angles:-

Raymond makes all his own pipe fitting unions, a good point to remember.

 

Regards.

 

Donald Mitchell

Castle Douglas

Bonnie Scotland

[SteambuffParticipant @steambuff]

Many Thanks Donald

[Author]

Posts