Author Topic: Stuart Boiler Feed Pump  (Read 8023 times)

Offline Florian Eberhard

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Stuart Boiler Feed Pump
« on: November 04, 2012, 05:16:55 PM »
Well, I wasn't very active in the last time. That's because of my studies (mechanical engineering; 5th semester now...)

However, I started a new project this summer.

I recently ordered a set of castings for the Stuart steam driven boiler feed pump and well, I started machining and now and then I find some time to continue...


How I received the set (I think my dealer added some more hex material)



The First part to be machined was the upper pump body:



It wasn't easy to do everything only with the lathe, for example here, I first cut a thread into the stub, where the water will come out later. That Way, I was able to machine the outside of the stub to be able to make threads later...: (The internal thread was drilled out later)



Finally, the flange to the lower part of the pump body was finished:



Then I took the lower pump body and the first thing that happened was that I found some bubbles. Well, I bored away all of the material with bubbles and solderd in a piece of gunmetal...



Afterwards, I drilled out the pump cylinder and finally reamed it to size. To machine the outside of the cylinder, I fixed the cylinder on a mandrel and took it in the lathe using a collet. (The mandrel actually is a cylindrical pin and has a quite tight fight in the Pump body. Additionally, I fixed it with some superglue.):



So much for now...

Cheers Florian

Online Jo

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Re: Stuart Boiler Feed Pump
« Reply #1 on: November 04, 2012, 05:32:53 PM »
Hey I have a set of these 8). I'll be watching with great interest.

Jo
Usus est optimum magister

Offline Florian Eberhard

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Re: Stuart Boiler Feed Pump
« Reply #2 on: November 04, 2012, 06:45:40 PM »
I've got some more Progress pictures ;) :

After the pump cylinder outside, I faced down the flange which connects the lower and upper part of the pump body:



Next step was to machine the stub on the suction side of the pump. Unfortunately, there was a small bubble in there as well and finally crashed the drill bit:



I then had to repair the stub. I machined it off and made a new one out of gunmetal:



Just ready for beeing soldered to the pump body:



That worked out pretty well and I continued with making studs to hold the two parts of the pump bodys together. Yes, all the hardware is being delievered but I only have metric threading tools and so I decided to make all the required screws and nuts by myself...:



And here together with the Nuts and washers. You can also see that instead of a gasket, I am using an O-ring to seal the connection between the two parts...:



Now put together:



and assembled with washers and nuts...:





Next part coming up as soon as its written...
« Last Edit: November 04, 2012, 07:03:42 PM by Florian Eberhard »

Offline Florian Eberhard

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Re: Stuart Boiler Feed Pump
« Reply #3 on: November 04, 2012, 07:23:26 PM »
After almost finishing the Pump body (I need my milling machine to finish it...), I continued with the Pump base.



I first made the Pump end planar with a file and also brought it into a square angle with the supporting face...:






Then, the center was marked on the opposite side (Steam cylinder side) to set the part on the faceplate. I had to use a piece of steel to bridge the bore in the center of the faceplate...:



With the center marked, I drilled a hole with 8mm in diameter. Then I could use the boring bar to expand the hole to the final diameter of 14 mm:


After the bore was finished, I face-turned the steam cylinder side to later proceed with the other side:



I have heard that the most important thing for getting a good running Pump is, to get the Pump-, and Steamcylinder exactly concentrial. I was thinking a lot until I had the solution:
I clamped a piece of steel rod into collets (could also have used the 3jaw but I like working with collets...)
This Piece then was machined so the Base would fit on it with a tight fit:






Next, I secured and fixed the Base with a screw and face-turned the pump side:



As well as on the other side, I first drilled to 8mm and then bored out to the final diameter.



This is the finished bore (with some oil on it - I already had some rust where I clamped the base on the rod; so I did immediately put some oil onto the finished surfaces....):



And finally with the pump body in place; The Pump cylinder also here fits tight into the base and needs to be pushed into with quite some effort. I will secure it with a screw from the bottom of the pum base (this detail is not entirely clear on the stuart plans and I think it is even missing...):





Well, this is where I am right now.
I can't say when I will find some time to continue; I hope quite soon ;)

Cheers Florian

Offline Don1966

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Re: Stuart Boiler Feed Pump
« Reply #4 on: November 04, 2012, 08:40:25 PM »
Hi Florian,  I will be following you as well. Nice save on the pump and looking good. I am purchasing a hand pump from PM Rearch so this may help me to machine mine when I get it. So following with interest.

Don

Online Jo

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Re: Stuart Boiler Feed Pump
« Reply #5 on: November 04, 2012, 09:09:07 PM »
Florian, You had some rotten luck with that gunmetal casting but as Don said you have done a really nice repair.

Stuart's castings have been up and down over the years :-\ looks like you got a bad one. Is the cast Iron ok? No nasty hard chilled spots?

Jo
Usus est optimum magister

Offline Florian Eberhard

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Re: Stuart Boiler Feed Pump
« Reply #6 on: November 04, 2012, 09:48:14 PM »
No nasty hard chilled spots?

No, nothing up to now...
The Problem with the drill bit could have been avoided, I guess I was not gentle enough as well...

However, I see it as a challenge...

« Last Edit: November 04, 2012, 10:13:59 PM by Florian Eberhard »

Offline steamer

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Re: Stuart Boiler Feed Pump
« Reply #7 on: November 04, 2012, 09:52:58 PM »
Looks great from here Florian!   I hear these pumps are tough to build...and I can appreciate that!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline ScroungerLee

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Re: Stuart Boiler Feed Pump
« Reply #8 on: November 04, 2012, 10:14:10 PM »
It looks like you are keeping well on track, especially fixing that casting.  Good job.

Lee

Mmmmm.... Shiny!

Offline gbritnell

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Re: Stuart Boiler Feed Pump
« Reply #9 on: November 05, 2012, 01:02:54 AM »
Nice repair on your mishap. I have found that gunmetal is almost like working with copper and is very grabby. By knocking the edge off of the drill and proceeding slowly usually avoids problems and heaven knows I've had my share. I built and have the Stuart pump on one of my displays but when I built it many years ago all of the castings were gunmetal.
gbritnell
Talent unshared is talent wasted.

Offline zeeprogrammer

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Re: Stuart Boiler Feed Pump
« Reply #10 on: November 05, 2012, 01:59:32 AM »
Nice stuff. Some very good looking parts despite the hardships.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"Found a peanut."
To work. To work.

Offline Florian Eberhard

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Re: Stuart Boiler Feed Pump
« Reply #11 on: November 05, 2012, 12:45:53 PM »
My experience is, that the material from those canstings is even more grabby than that kind of gunmetal, I have been using up to now. 
However, I now got me another drillbit especially for brass and gunmetal.

I have seen pictures from sets of casting with all the castings out of gunmetal,  I would really have appreciated to get such a set but I guess they are quite rare...
(It wouldn't have resulted in such mess from machining like it does witz cast iron...)

George; how did you make the ball seats? Just a sharp edge?

Florian
« Last Edit: November 05, 2012, 09:08:11 PM by Florian Eberhard »

Offline NickG

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Re: Stuart Boiler Feed Pump
« Reply #12 on: November 05, 2012, 08:31:53 PM »
Nice work there Florian, just goes to show this machining castings thing is far from easy. I like the way you are leaving the cast surfaces as cast - as intended.  :ThumbsUp:

Offline Florian Eberhard

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Re: Stuart Boiler Feed Pump
« Reply #13 on: November 05, 2012, 08:46:44 PM »
If I didn't leave the cast surfaces, I could directly build it from stock material...  ;)

I really like the look of cast surfaces on all the mechanical stuff...

I am not sure if and how i am going to paint it in the end...
But there is enough time to find that out :)

Florian

Offline NickG

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Re: Stuart Boiler Feed Pump
« Reply #14 on: November 05, 2012, 09:18:23 PM »
Exactly, I've seen some people machine or dress all the surfaces - sort of defeating the point of a casting but each to his own I guess.

I was surprised how well gun metal silver solders - one of the few things I've made from castings, probably the only successful thing was a hand pump for Sweet Pea loco which was two castings silver soldered together.

Will be a useful bit of kit this, will you be using this with a boiler at some point?

Nick