Author Topic: Stuart Major Beam Engine  (Read 29249 times)

Online b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13445
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: Stuart Major Beam Engine
« Reply #135 on: June 22, 2019, 12:58:19 PM »
This one fell off my radar for a while but you have really made some fantastic progress Andy. I am back up to speed now....impressive work!!

Bill

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 576
Re: Stuart Major Beam Engine
« Reply #136 on: June 23, 2019, 12:31:33 PM »
Hi Dave, yes a bit horticultural. I've been pruning lots of bushes this week in particular a row of Berberis (nasty thorns) that was getting out of control.
I agree with you about reasons for working to hole sizes. However, I became too enthusiastic and started work on the crosshead, if it all fits then I'll consider myself lucky but having worked out the procedure to make it I won't feel too bad if I have to make another. I'll start on the Parallel and Radius Rods this afternoon if I have suitable material.

Yesterday we drove to Croome Court (National Trust near Worcester) in my wife's MX5 with the roof down and got sunburned - some people never learn ! :facepalm2: ::) so not fit for model engineering yesterday evening.

Piston rod crosshead 1 by Andy, on Flickr

I started with a 7/8" bar of mild steel  (believed to be EN1A) and turned down one end to 5/8" to fit in a multi collet chuck and an ER40 collet and square block later on and proceeded to turn it to a bobbin shape.

 WP_20190621_14_10_46_Pro (2) by Andy, on Flickr

WP_20190621_15_20_13_Pro (2) by Andy, on Flickr

Using a parting tool for the 9/32" diameter sections.

WP_20190621_18_04_55_Pro (2) by Andy, on Flickr

Leaving about an eighth of an inch stub for the centre which will be removed later. This is where I'd got to Friday night. My plan is to mill the central section into its rectangular shape with the crosshead still attached to the bar, held in a square ER40 collet block or a dividing head.

WP_20190621_18_14_39_Pro (2) by Andy, on Flickr

Hi Bill, I'm not surprised it disappeared off your radar, it had been left untouched for three years!

Andy

« Last Edit: June 24, 2019, 09:22:08 AM by Chipmaster »

Offline ettingtonliam

  • Full Member
  • ****
  • Posts: 32
Re: Stuart Major Beam Engine
« Reply #137 on: June 23, 2019, 01:30:21 PM »
Impressive stuff on the beam engine, its one I always wanted to do myself but never got around to.

Am I right in thinking you are in Redditch? I'm in Inkberrow!
I'm half way through an Alyn Foundry Robinson hot air engine, and getting into a 7 1/4" gauge Locomotion, but I don't think we are allowed to talk locos on here.
Doesn't the beam engine have some long slender fishbellied rods in the valve gear and parallel motion? If it does I'm keen to see how you do them. Locomotion has a number of rods, about 8" long 7/32" dia down to 3/16" dia with a fishbelly profile. I'm at a loss to know how to machine them. The only way I can think of is to spin them up in the lathe at a decent speed, and attack them with a series of flat files followed by emery cloth.

Richard

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 576
Re: Stuart Major Beam Engine
« Reply #138 on: June 23, 2019, 01:48:36 PM »
Hello Richard, yes Iím in Redditch, good to hear from a MEM member who lives just a few miles away.
We often drive through Inkberrow, yesterday we must have driven past you on the way to Croome Court. I finished an Alyn Foundry Robinson hot air engine earlier this year and I machined fish bellied connecting rods for a Stuart Twin Victoria. Iíll send you my phone number via a Personal Message.

Andy

Offline Stuart

  • Full Member
  • ****
  • Posts: 1742
  • Tilchestune UK
Re: Stuart Major Beam Engine
« Reply #139 on: June 23, 2019, 04:42:29 PM »
Richard

There is a way not my idea nor have I tried it , but for a long and SLENDER rod note slender


Put a centre hole in each end
Offset the tail stock then grip on end in the chuck get a firm hold then put the center in you wil have to bend the rod to engage it

Then turn from the TS end half way rinse and repeat the other end

Theory is that a beam deflected will form a curve

Caveat emptor

Do not try this on a light lathe you need industrial strength to stand the abuse the headstock bearings will take

Note disclaimer I do not recommend this and I take no responsibility for any machine tool harmed in any way

Stusrt
My aim is for a accurate part with a good finish

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 286
Re: Stuart Major Beam Engine
« Reply #140 on: June 24, 2019, 01:29:09 PM »
Hi Andy, don't blame you for fancying an early crack at making the crosshead, it's the sort of component that one has an itch to have a go at!
    I was interested in the Victoria rod that you showed, as that transition from the round rod to a flat sided U fork is a tricky thing that has come off nicely, and I imagine needed careful handwork.  I was looking at just the same requirement last evening along with a friend who is making a James Coombes engine, which calls for round, flat sided bosses at the end of fish bellied con rods, and we were mulling over ways of avoiding the awkward geometry that Stuart has imposed on the builder.  Never came to any very convincing decision..    Dave
« Last Edit: June 24, 2019, 01:46:42 PM by Chipswitheverything »

Offline Jasonb

  • Full Member
  • *****
  • Posts: 6463
  • Surrey, UK
Re: Stuart Major Beam Engine
« Reply #141 on: June 24, 2019, 01:45:50 PM »
I'm at a loss to know how to machine them. The only way I can think of is to spin them up in the lathe at a decent speed, and attack them with a series of flat files followed by emery cloth.

I tend to divide the length into 3, taper the end thirds then blend with files. See my couple of posts on this page

https://www.model-engineer.co.uk/forums/postings.asp?th=86341&p=14

I have also used the method Stuart describes which is ideal for a classical column though I don't have an industrial lathe :o


Offline Chipmaster

  • Full Member
  • ****
  • Posts: 576
Re: Stuart Major Beam Engine
« Reply #142 on: June 24, 2019, 09:15:21 PM »
Hi Dave, indeed the pair of Stuart Twin Victoria connecting rods required a lot of careful work with files. I used filing buttons to produce the rounded ends. The starting point was flat steel bars.  The holes for the big end and crosshead U fork were drilled and reamed first then the rods were turned down between centres on my lathe. The taper turning attachment was used to produce the fish bellied shape by altering the taper at intervals along the connecting rod. When machining was completed and the rods were off the lathe the filing began. First I opened up the U fork with a hacksaw, plugged my iPod into the docking station in my workshop and started filing. I compiled a playlist for for the job "Music to file Con Rods by", the laid back / calming music was vital.

Turning between centres.

Connecting Rod by Andy, on Flickr

Connecting Rod by Andy, on Flickr

The fish bellied shape - subtle.
Connecting Rod by Andy, on Flickr

Rod sitting on the plan - shows what was required.
 
Photo 96 by Andy, on Flickr

I didn't take any photos of the progress with filing, only the finished connecting rods.

Connecting Rod by Andy, on Flickr

Connecting Rod by Andy, on Flickr

Connecting Rod by Andy, on Flickr

Most of the work on my Twin Victoria was done before I joined Model Engine Maker. However, I added a brief build log on MEM if anyone is interested. I'm not sure how to paste a link to it, I'll post this then have a go. 

http://www.modelenginemaker.com/index.php/topic,3378.msg59892.html#msg59892

Andy
« Last Edit: June 24, 2019, 09:24:40 PM by Chipmaster »

Offline creepy

  • Full Member
  • ****
  • Posts: 22
Re: Stuart Major Beam Engine
« Reply #143 on: June 25, 2019, 12:02:12 AM »
Great work Andy
I don't know how you do such intricate work.
I have to do the same thing on the Stuart Beam, (boy I'm looking forward to that ::)) the build is looking great, I'm learning so much from the master.
Thank you
Gary

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 286
Re: Stuart Major Beam Engine
« Reply #144 on: June 25, 2019, 01:53:57 PM »
Hi Andy, thanks for putting up the interesting photo sequence, I commend your filing, though I think my preference would have been to machine most of it using my Geo. H Thomas pattern small rotary table , made long ago. ( Been mighty useful for lots of the fiddly stuff on the Major beam engine, like the governor swing links, as one can set the stops minutely to limit the table rotation .  Also the table rotates quickly, just pulled round by hand, ideal for small radii which would be very tedious if one had to wind the handle of a larger table round dozens of times just to do a 1/4" dia boss...  ).  Admittedly, the machining would not sort out the final blending of the U fork and the rod!  Multi axis CNC would be handy there..!!   Dave

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 576
Re: Stuart Major Beam Engine
« Reply #145 on: June 25, 2019, 02:40:30 PM »
Hi Dave, my preference is also to machine whenever possible if I have the appropriate tools. Iíve just come in from my garage for a break after sawing through various steel bars  :old:
There are a couple of laser cutting firms close by. One does two dimension and is quite prepared to do odd jobs. The other firm does three dimensions which would be very useful but they canít interrupt their busy schedule with my bits and pieces.

Andy

Offline Chipmaster

  • Full Member
  • ****
  • Posts: 576
Re: Stuart Major Beam Engine
« Reply #146 on: July 12, 2019, 09:17:05 PM »
With the embryonic cross head held in a square collet block it was easy to mill the central section into a rectangular shape,

Crosshead by Andy, on Flickr

WP_20190625_17_00_39_Pro (2) by Andy, on Flickr

WP_20190625_17_21_19_Pro (2) by Andy, on Flickr

Then back in the lathe to machine off the end that had been used to support the job with a centre,

WP_20190712_16_32_19_Pro by Andy, on Flickr

Followed by parting off the cross head and putting a matching chamfer on the other end,

WP_20190712_16_47_16_Pro (2) by Andy, on Flickr

WP_20190712_16_48_52_Pro by Andy, on Flickr

The cross head is fitted to the tapered end of the piston rod by using a 1/4" taper pin reamer. I did a test with a piece of 1/2" square brass bar to determine how far to go with the taper reamer. it would have been rather disappointing to ruin the cross head with over enthusiastic reaming at this stage. So, a piece of insulating tape was wrapped around the reamer at the appropriate point. 

WP_20190712_17_48_31_Pro (2) by Andy, on Flickr
WP_20190712_17_48_49_Pro (2) by Andy, on Flickr

I drilled a 3/16" pilot hole through the cross head then followed through with the taper reamer using Trefolex cutting paste, love the smell of Trefolex.

WP_20190712_17_30_46_Pro (2) by Andy, on Flickr

WP_20190712_17_34_56_Pro (2) by Andy, on Flickr

Here's the cross head sitting on the piston rod

WP_20190712_17_47_13_Pro (2) by Andy, on Flickr
WP_20190712_17_49_06_Pro (2) by Andy, on Flickr

Now I have to decide the best way to cut a slot to take the wedge that passes though the cross head and piston rod,

Andy

Offline Chipswitheverything

  • Full Member
  • ****
  • Posts: 286
Re: Stuart Major Beam Engine
« Reply #147 on: July 13, 2019, 12:35:45 PM »
That's looking good Andy, bringing back memories...!   I did the slot in the two components by the usual drilling then filing method in this case, but the slot size is big enough to get standard sized needle files into.  Helps to have safe edges and crisp corners on some files.   Dave