Author Topic: Stuart Major Beam Engine  (Read 86817 times)

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #300 on: July 24, 2020, 05:04:09 PM »
Thanks Dave, I'm wondering whether I'll ever finish the eccentric strap.

Looking ahead to the valve levers,

Valve Lever by Andy, on Flickr

The drawing suggests they are "Brazed to shaft", here's a picture of your valve levers,

Valve levers on shaft by Andy, on Flickr

Did you solder your valve levers to the valve shaft?

I presume it is a precaution in case a taper pin came adrift. The momentum from the 14" flywheel could potentially bend or break things should the valve levers cease to operate in unison. Do you or other members, particularly any Stuart Major builders have an opinion?

Andy

Offline Chipswitheverything

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Re: Stuart Major Beam Engine
« Reply #301 on: July 25, 2020, 01:57:17 PM »
Hi Andy, have just dug my assembly as per the photo out of its place of hiding!, and I have taper pinned the levers.  I don't recall the brazing instruction, maybe not on my set of dwgs?, but I wouldn't fancy doing that anyway.   I seem to recall that this was another instance where I disregarded Stuart's dimensions for the location along the shaft, and worked things out from the engine itself in a lash up - just as well, as I believe there was some variation, and I think that the position of the hand lever at the end similarly needed a rethink.  The datum for that is related to the position along the crankshaft of your eccentric and sheave and lining up the latching pin of course.    My photos of drilling the taper pin holes using the GHT Fingerplate may show that the levers were set up along the shaft with the help of that to jig it all up, maintaining the worked out positions.    A drop of Loctite on t' pins and or shaft would give the extra security when  ( when! ) final assembly takes place.   Dave

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #302 on: July 28, 2020, 10:10:36 PM »
Thanks for your input Dave, I have finished the eccentric strap and spent time working on the pair of valve shaft bearings and caps.

Valve Shaft Bearing and Cap by Andy, on Flickr

These are gunmetal castings, after fettling and marking out I drilled the 5BA clearance holes in the feet then drilled and tapped the 8BA holes for the studs that will hold the caps. The castings were then mounted on a 1/2" square bar so that they could be held in the lathe's toolpost which was clocked to ensure it was at right angles to the lathe spindle. A 6" x 1/32" slitting saw was used to separate the caps.

S Major 1140 by Andy, on Flickr

S Major 1130 by Andy, on Flickr

S Major 1133 by Andy, on Flickr

S Major 1134 by Andy, on Flickr

The 1/2" square bar was contrived to be long enough to clamp on a faceplate for boring the bearings out to 7/32"

S Major 1147 by Andy, on Flickr

S Major 1150 (2) by Andy, on Flickr

To finish off the caps were drilled and tapped 5BA for fitting oil cups. Here are the bearings temporarily held by 5BA slotted head screws and a 7/32" diameter bar to check alignment.

S Major 1155 by Andy, on Flickr

Andy
« Last Edit: July 29, 2020, 06:24:21 AM by Chipmaster »

Online crueby

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Re: Stuart Major Beam Engine
« Reply #303 on: July 28, 2020, 11:49:24 PM »
nicely done, I like the way you held the parts on the faceplate for drilling.
 :popcorn: :popcorn: :popcorn:

Offline Chipswitheverything

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Re: Stuart Major Beam Engine
« Reply #304 on: July 31, 2020, 03:44:51 PM »
Little bearings look nice Andy, ditto the working method on the somewhat fiddly bits.   Glad to be told that the slot headed screws were temporary or I should have worried about that all day...!!    Dave

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #305 on: July 31, 2020, 07:02:11 PM »
Thanks Chris and Dave, I can’t use a slitting saw on my milling machine hence I use my lathe. My old Autolock chuck can’t hold the short stub of the arbor and run true, the wobble at the rim of a six inch slitting saw is alarming. Hot dry weather is slowing model engineering down, I’m spending more time running engines in the garden instead.

Andy

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #306 on: August 04, 2020, 10:17:36 PM »
The two Valve Levers were next,

Valve levr 2 by Andy, on Flickr

I milled a piece of flat mild steel bar to within about 0.025" of the required thickness and width then cut the bar to make the two levers. To ensure they matched with 7/8" between centres I drilled the 9/32" hole in each then fitted them on a short 9/32 stub glued them together then drilled the 4BA clearance hole through both.   

S Major 1156 (2) by Andy, on Flickr

Each piece was scribed to show the 1/8" thick lever or crank.

S Major 1157 (2) by Andy, on Flickr

Then one at a time they were mounted on an arbor on my lathe, held with a 15/32" diameter collar and a 1/4 whit nut on the end of the arbor. The crank was machined down to the line one side then re-positioned on the arbor for the other side to be machined down to the line.

S Major 1161 by Andy, on Flickr

 S Major 1162 by Andy, on Flickr

At this stage I had two valve levers to be profiled as per the drawing.

S Major 1165 (2) by Andy, on Flickr

S Major 1166 (2) by Andy, on Flickr

About three hours filing followed using the arbor and 5/16" filing buttons as guides.

S Major 1169 by Andy, on Flickr

S Major 1172 by Andy, on Flickr

At close of play this evening......

S Major 1176 by Andy, on Flickr
S Major 1177 by Andy, on Flickr
S Major 1178 by Andy, on Flickr

They now need much more polishing and a 1/32" rebate machined on the outward ends of the hub to follow the drawing.

Andy

Offline Chipswitheverything

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Re: Stuart Major Beam Engine
« Reply #307 on: August 06, 2020, 03:42:47 PM »
Nice to have some of these rather labour intensive little items ticked off, or nearly so.  I think that I used the little GHT pull round rotary table on these and similar, being able to set the dead stops makes operations less nerve racking, but working from both sides means more fiddling about however you plan it...    Dave

Offline scc

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Re: Stuart Major Beam Engine
« Reply #308 on: August 06, 2020, 09:02:07 PM »
Nice job Andy,   I've just spent several hours filing bits on my next project.  I have to keep stopping for a rest these days :old:  but it's all worthwhile when you end up with nice parts made by hand. :cheers:       Terry

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #309 on: August 07, 2020, 08:46:17 PM »
Thanks for the encouraging words Dave and Terry perhaps it will be finished this year......

Spent too long trying to edit videos this morning, click on this window below which will take you to my Flickr album then click on the Play > button in the centre of the screen.

HG Wednesday Club by Andy, on Flickr

My workshop was too hot for comfort this afternoon so I made the valve shaft and let the lathe do all the work.

Valve shaft by Andy, on Flickr

9/32" steel held in a Burnerd multisize collet chuck.

S Major 1183 by Andy, on Flickr

Used a parting tool on the journals.

S Major 1185 by Andy, on Flickr

The fit was pretty good, just a little adjustment to the distance between the journals to achieve a smooth action.

 S Major 1186 by Andy, on Flickr
S Major 1187 by Andy, on Flickr

With the Valve levers loosely assembled.
S Major 1190 by Andy, on Flickr
S Major 1193 by Andy, on Flickr

This is the engine so far,

S Major 1194 by Andy, on Flickr
S Major 1196 by Andy, on Flickr
S Major 1197 by Andy, on Flickr

Andy

Offline Chipswitheverything

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Re: Stuart Major Beam Engine
« Reply #310 on: August 08, 2020, 03:33:21 PM »
Nice to see the update pictures of the whole assembly as it comes together, becomes impressive as it builds up and a spur to continuing with the further bits. I found that, as my beam engine was getting to that stage, one gets a real feeling of the way in which the engine captures the flavour of Victorian engineering and the very different machine aesthetic of those far off days:   - it doesn't resemble anything that would be designed or sold in modern times when almost everything has to be hidden away behind a slick exterior and shiny surfaces!  Time warp stuff!!     Dave

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #311 on: August 20, 2020, 09:53:26 PM »
The Valve Rod Crosshead was next.
I wasn't confident with this and couldn't find any examples of how to make a similar part on the internet. There are pictures, most perfect (hard acts to follow) and a few where the builders appear to have given up on producing a crosshead as drawn.

The drawing.
Valve Rod Crosshead by Andy, on Flickr

The crosshead is a part that I thought would require great care, thinking of the limitations of my milling machine's accuracy - dodgy vernier scales and no DRO. I also thought that a GHT pull round rotary table with adjustable dead stops would make the job easier, just a shame I don't have one.

Reckoned that it would be best to machine the 13/64" diameter journals with the job mounted on a lathe between centres. To ensure the axis would be at a right angle to the 5BA clearance hole in the centre I chose a length of flat 1" x 1/2" mild steel bar, marked it out and drilled the 1/8" diameter hole first. The stock was much longer than the part required so that I could eventually saw off the centre drilled stubs and have flat polished ends.

Using a 1/4" slot drill I milled four slots right through and centred the two ends of the bar ready to go in the lathe.

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

 Valve Rod Crosshead by Andy, on Flickr

Turning the crosshead between centres. I reasoned that the excess stock would keep the job rigid whilst machining with interrupted cuts, just as well as the steel wasn't free cutting stuff.

Valve Rod Crosshead by Andy, on Flickr

After sawing off the surplus bits, more lathe and filing work ensued.

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

No pictures of machining the journals, I forgot, anyway I used a 2mm parting tool, very carefully because I was experiencing some chatter - presumably the job was flexing. 

The job was then mounted on an arbor in order to machine the ends of the hub for want of a better word. This job highlighted errors that required yet more hand filing.

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

After sawing off the two stubs with centre drill holes and polishing .....the finished article. It's not perfectly symmetrical but on this occasion I'll settle for near enough.

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

Valve Rod Crosshead by Andy, on Flickr

Andy


Offline Johnmcc69

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Re: Stuart Major Beam Engine
« Reply #312 on: August 25, 2020, 06:22:49 PM »
 :ThumbsUp:
 Fantastic job on that crosshead!
 :popcorn:
 John

Offline Chipswitheverything

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Re: Stuart Major Beam Engine
« Reply #313 on: August 26, 2020, 03:14:17 PM »
Hi Andy, nice procedure on the crosshead, and a good result. I chonked mine out of 1/2" sq. stock , mostly on the mill with one end of the stock in the vice and the other clamped against an angle plate.  I formed the boss in the cente by nibbling up to a filing button of the boss dia. in many gentle cuts.  The DRO was useful for the rest of the slicing away.  Definitely one of the more brain teasing of the awkward little bits and nice to have out of the way, though there are still just a few more..!  Dave

Offline Chipmaster

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Re: Stuart Major Beam Engine
« Reply #314 on: August 30, 2020, 09:44:14 PM »
Hi John and Dave, it is very encouraging to receive your comments. I hope to start making the two valve motion links this week.
Andy

 

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