James Booth 1843 Rectilinear Engine - Orphan

[Admiral_dk]

It looks like you on a roll, with this one now, Jo 
Nice to see that you feel up to be in the shop again   

Per

[steam guy willy]

Hi Jo, looking good 

Willy

[bent]

Hmm.  Original "machinist" went blindly off the drawings without figuring out where the significant features needed to be?

[Jo]

Thanks Guys 

I suspect the original builder tried doing this as his first engine and learnt a lot 

I have been faffing about trying to find a suitable boring bar. I couldn't use my 12mm long reach one because the wider bit towards the end caught the top hole when I tried to cut the lower hole  So I did it using a 10mm diameter boring bar 



Not ideal as I had to go slowly using small cuts to avoid the tool flexing too much. Thankfully Tgs has power feeds 

All done. The hole is now 15.8mm diameter. Which means I can ream it out if required to a standard size but it is looking ok:

 

Because the central bearing keep slot wider is I am thinking of leaving the larger diameter of the bearings a little bigger 

Jo

[propforward]

This is a great engine. Coming along very nicely. It's a really fascinating design, will be great to see it continue to progress.

[Jo]

Thank you Stuart 

I've just machined up the set of main bearings:



The bearings line up nicely on the columns but the column lengths need a bit of an adjustment 


The tops of the columns need some Acorn nuts 

Jo

[Jo]

The acorn nuts must be all the same which means I need a form tool. I am using a router bit:



Once the tool is set up it is important to do all of them before moving the tool so I cut tops on both ends of five rods then parted them off:



Not forgetting to add a little chamfer. Then drill and tap 2BA and finish with some metal protector so they don't tarnish 



Time to sort out the lengths of the columns   

Jo

[crueby]

Nice trick with the router bit!
 

[Roger B]

Still following and enjoying  plus one for the router bit   

[Jo]

Thanks Chris and Roger 

If you recall I mentioned that the columns were of different lengths. Having disassembled the engine I have found that one was .8mm longer than the rest. This was set up between centres:



And a little taken off the bottom of the curved bit of the column and reshaped. Two other columns had a smidgen taken off so now I have a set of columns all within 0.1mm of each other:



Next to look at is the cross head guides. These originally came as a large flat casting which needed to be bored to give the curved shape and the outside milled flat. Finally taken apart each casting gives four pieces as on the left:



I've seen at least one "feature" on these   

Jo

[wagnmkr]

Good looking parts Jo ... and another vote for the router bit trick!

[Jo]

Thank you Tom 

The outer holes in these guides are what is known as long holes. What this means is that the hole depth in comparison with the diameter is greater than 5 so the drill is likely to get bored and go off for a wander  I felt the need to adjust this with a needle file before rounding over the ends. The ends must be rounded because if you recall I milled the slots for these brackets and the slot has a rounded end.

Having knocked up some 7BA studs it can go together:




But it is not that easy  If you look carefully you will notice that the slots taper towards the centre - this meant that the brackets needed to be moved further out in the slots = a bit more filing and rounding.

What is needed is for the slots to be parallel so the guide blocks which are effectively the cross heads can run smoothly:



I suspect this is one of those bits will give hours of fun as part of the final assembly.   

Jo

[Jo]

I decided it was time to review the remaining bits 



Nice as they are I don't think I should risk using those two links as there is a risk the centres are not right. There is a heap of nuts and bolts (between paper and the plastic lid) that I am not convinced are from this engine    The spacers are missing, as are the cranks and both sets of the links. I didn't feel like tackling that today as it was a bit cold... 

Instead I decided to clean up the flywheel and pulley. The pulley had been machined but was rusty - it needs machining again. The Flywheel had never been touched  When I introduced it to a file I found out why  The flashing was hard as  Having ground the flashing around the spokes down using my Foredom (and a diamond file at one point  ) I got it cleaned up and have given it a quick squirt of primer so I can see any more bits that need sorting out:



I left the workshop covered with grinding dust and not feeling I had achieved much but it took a while...

Jo

[Jasonb]

When if I resurrect mine I too will be remaking the links, at the time I would have marked them out by hand so doubt they will be as accurate as I could do them now. plus it will be as quick with new metal than cleaning up the old.

As my Emco at the time could only swing 200mm dia I took my flywheel to an old boy who offered machining services from his flat over towards Dartford and he did a good job of that, can't see that there were any issues with the casting unlike the GM ones. I did machine a new Stuart 7" one yesterday and that was a very good casting both metal and shape wise.

You could always stay in the warm and do the work on Sexy and his new stable mate

[Jo]

You could always stay in the warm and do the work on Sexy and his new stable mate

Schoey is still out in the main workshop and if I go into the Library with castings there is a risk being trampled 

Tomorrow will be warmer in the workshop as I only get a couple of hours in the workshop on Monday afternoons and it takes more than that to get any real heat in the workshop. The Night storage heater will get it nice and warm for tomorrow morning then running the tooling will keep it warm until the sun goes down

Jo