Stuart Major Beam Engine

[Chipmaster]

Hi Chris, like you I've had failures using soft solder. This time I contrived to use a longer silver solder joint for added strength. However, because of the higher temperature involved you have to be careful not to melt or distort delicate brass parts when trying to separate them. I've done that, very frustrating to see a few hours work wrecked in that way.
Andy

[Chipmaster]

The next step was to make the pair of brass bushes that fit on the forked ends of the connecting rod.

Fork end bush by Andy, on Flickr

To ensure they matched I machined them together in one sitting.

WP_20190518_15_43_46_Pro by Andy, on Flickr

Milled half the diameter away.

WP_20190518_16_02_08_Pro by Andy, on Flickr

Soldered on a rectangular piece of brass using silver solder.

WP_20190518_16_23_22_Pro by Andy, on Flickr

Milled channels in the square half of the bush to match the semi circular half.

WP_20190519_16_33_49_Pro (2) by Andy, on Flickr

Drilled and reamed the bushes to 9/32" diameter.

WP_20190519_17_16_04_Pro (2) by Andy, on Flickr

Parting off each bush

WP_20190519_17_23_48_Pro by Andy, on Flickr
WP_20190519_17_24_30_Pro by Andy, on Flickr
WP_20190519_17_37_40_Pro by Andy, on Flickr

Bushes separated into halves by carefully heating to break the silver solder joint.

WP_20190519_17_55_53_Pro by Andy, on Flickr

Fitted on the connecting rod fork, retained by the straps and temporary wedges.

WP_20190520_16_28_28_Pro by Andy, on Flickr

The bearings seem to be a good fit, there is no slack or binding. Jury rigged and it turns over smoothly.

WP_20190520_20_02_06_Pro (2) by Andy, on Flickr

There is a long way to go with this engine particularly trying to achieve the beautiful finishes I see on other Stuart Major seen in pictures and videos on the Internet

Andy

[gbritnell]

Nice job on the brasses Andy!
gbritnell

[Chipswitheverything]

Hi Andy, a good result on the split brasses : there is a load of work in these innocent looking components, more than meets the eye once they are all finished, and lucky you, you have eight more pairs to do in the parallel motion links, and then the tiddly half shells for the oval ended radius rods....! But very satisfying to be able to put some assemblies together and see it moving sweetly.  Dave

[Chipmaster]

Cheers George and Dave, you certainly have to be in it for the long term with this one. I have started work on a set of I F Allman castings which I’ll probably be able to complete sooner following Jason B’s excellent drawings.

Andy

[Jasonb]

Looks like you have got all the fun bits done now Andy, only the fiddly little bits left

Allman is making good progress, at this rate I'll need to complete a few more drawings.

Got this little one to run today but had to forego the flames

<a href="https://www.youtube.com/watch?v=kYWZrxXmRgg" target="_blank">http://www.youtube.com/watch?v=kYWZrxXmRgg</a>

[jeff l]

if interested I made a form tool  for the parallel motion bearing spacers , it made the job of making these easy . You can borrow it if you wish just pay postage to and from .Or I can give you instructions on how to make one your choice .Jeff

[creepy]

Hi Andy
I'm fairly new here, but I have been through all your build videos of the Major and all I can say is wow, what a fantastic build you are doing.
Your skill to build this very complex engine is outstanding, I don't know if a lot of people outside the forum could appreciate the amount of work that goes into a build like this.
I'm currently building it's little brother and that is very taxing, I don't have the equipment to build something this big, so I'll be watching you complete this monster.
What I love about Model Engineers is how different we approach a build, we all learn from each other.
All the best.
Gary

[Chipmaster]

Well Gary I am overwhelmed by that. I have to say there are other MEM members who have built the Stuart Major before me who have provided plenty of practical advice via posts and personal messages. It could be a daunting project so I like to take breaks making other smaller models. Like you I don’t have all the appropriate equipment for many aspects of  the build but improvising and overcoming problems is a part of this hobby that gives great satisfaction.
Andy

[Chipmaster]

This afternoon I had a go at the piston, the kit included a piece of 55mm diameter cast iron bar sawn perfectly square and long enough for holding in the chuck. The kit also includes two cast iron piston rings

Copied from the plans:

Piston by Andy, on Flickr

Turned down to 1.75" and forming the piston ring grooves with a parting tool.
WP_20190613_17_08_33_Pro by Andy, on Flickr

Tapering the bore using a tiny boring tool and offsetting the topslide.

WP_20190613_17_37_46_Pro by Andy, on Flickr
WP_20190613_17_37_54_Pro by Andy, on Flickr

Forming the recess in the top of the piston some cuts with the lathe in reverse.

WP_20190613_20_28_20_Pro by Andy, on Flickr

and some cuts with the lathe running forwards,

WP_20190613_20_33_04_Pro by Andy, on Flickr

Recess done.

WP_20190613_20_33_13_Pro by Andy, on Flickr

Parting off the piston

WP_20190613_20_37_01_Pro by Andy, on Flickr

Almost there

WP_20190613_20_47_13_Pro by Andy, on Flickr

It's off,  phew 

WP_20190613_20_53_10_Pro by Andy, on Flickr

I'll do the recess on the other side tomorrow.

WP_20190613_20_56_29_Pro by Andy, on Flickr

Andy

[gary.a.ayres]

Phenomenal build...!

[creepy]

Great work Andy.
I hate machining pistons
Gary

[Chipmaster]

Finishing the piston.
Boring out the recess in the underside of the piston.

Piston by Andy, on Flickr

Piston by Andy, on Flickr

Finished
Piston by Andy, on Flickr


I made a dummy piston rod because I only had a short length of 1/4" diameter stainless steel. The steel bar was held in a multi-collet chuck and the taper formed by angling the topslide to six degrees. A 2BA thread was cut on the end of the rod.

Piston rod by Andy, on Flickr

Piston rod by Andy, on Flickr

Looks OK.

Piston by Andy, on Flickr

Piston by Andy, on Flickr

Hi Gary, I reckon I prefer machining pistons - no surprises because I can see what's happening unlike boring long cylinders with flexing boring bars, oh and I like working with cast iron apart from the mess.

Andy

[Ye-Ole Steam Dude]

Hello Andy,

Still following along and admiring all your work.

Have a great day,
Thomas

[Chipmaster]

Hi Thomas, thank you for your interest and compliments. I have started work on the cylinder head this afternoon. Had to stop when I was called in for dinner this evening.

Andy