Author Topic: How would you make this tapered column for the Williamson engine  (Read 825 times)

Offline geoff5269

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I have already made this engine from castings but after a comment on my youtube video i wondered if it could be scratch built as the castings cost nearly 500.
My thought was to buy a piece of 2 1/2" Ali tube and cut out the openings and then remove 9mm at the top of each opening and then squeeze the top down to the smaller 2" diameter.
It's probably harder to do than it sounds so i thought i would see if any one else has an idea. I enclose the plan and pics.  You can see the supplied casting is a bit rough.
Geoff

Offline Jasonb

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Re: How would you make this tapered column for the Williamson engine
« Reply #1 on: January 06, 2021, 11:56:12 AM »
I think it could be done by either cutting from solid or fabrication.

For the solid method turn the outer taper to then size of the flat bead around the cut outs. Bore either end of the cut out and then join the two holes completing the four openings. Then take a ball nosed cutter to do the flute with the column mounted at an angle and rotary table used to index the flutes. Finally mill down the "crests" between and around the flutes to make the bead around the openings sit proud

To fabricate then turn the taper to a smaller diameter equal the the crests of the flutes. Use CAD to work out the true shape of the flat beads around the openings and cut then from sheet ( you only need cut the outer shape) then fix to the tapered column. You can now form the four openings as before cutting through the thickening sheet and the actual column. Then mill the flutes but you would not need to go as deep.

Fabricated would be slightly easier as a bit trickier going around the outside of the flat bead with a manual mill though the CNC would be OK.

At least using one of these methods you would not get that nasty problem where half the flutes are higher than the others, no doubt needed a 4 piece pattern so that it could be extracted from the mould and they did not line the parts up too well. Fabricated would also allow the flutes to be done as drawing and run right into the edge of the opening's bead rather than the rounded end of the cast one.
« Last Edit: January 06, 2021, 12:03:21 PM by Jasonb »

Offline Jo

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Re: How would you make this tapered column for the Williamson engine
« Reply #2 on: January 06, 2021, 11:58:37 AM »
I was going to cut the one for my much bigger one from solid. And then add the facings round the holes separately

Jo
Enjoyment is more important than achievement.

Offline Jasonb

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Re: How would you make this tapered column for the Williamson engine
« Reply #3 on: January 06, 2021, 12:11:11 PM »
What no casting Jo :'(

Sounds like we are both thinking along the same lines. Would you do it all as one of have a shorter fluted part with the top and bottom turned parts separate and located with a short spigot?

Offline Jo

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Re: How would you make this tapered column for the Williamson engine
« Reply #4 on: January 06, 2021, 12:17:59 PM »
What no casting Jo :'(

Foundry isn't open/doing anything  :hammerbash:

Jo
Enjoyment is more important than achievement.

Offline Jasonb

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Re: How would you make this tapered column for the Williamson engine
« Reply #5 on: January 06, 2021, 12:26:24 PM »
Is it only the column you are missing or all the other castings too?

Anyway who needs castings when you can get a column out of a bit of steel for 50 from Steelcitygav and still be left with a good size pile of swarf, should be a suitable casting hiding somewhere in this lot

Offline Georg49

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Re: How would you make this tapered column for the Williamson engine
« Reply #6 on: January 06, 2021, 06:54:56 PM »
I made my column out of a bar of solid aluminium, 10% larger than the official Williamson. I started by taper turning the inside and the outside using a taper turning attachment. I left a cylindrical collar on the top of the column and drilled 36 indexing holes. I mounted the column on V-blocks on the mill table and shimmed it so the top surface was level and improvised an indexing detent. After milling 36 grooves with a 3mm  ball nose cutter I drilled 8 holes with a holesaw and elongated the slots. The rims of the slots were glued on. Regards, George

Offline geoff5269

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Re: How would you make this tapered column for the Williamson engine
« Reply #7 on: January 06, 2021, 08:19:53 PM »
George
That's an amazing technique and it looks better than the casting, now we know it is possible to make one the size we want. It would be nice to see the finished engine.
Thanks for sharing on your first post.
Geoff

Offline Elam Works

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Re: How would you make this tapered column for the Williamson engine
« Reply #8 on: January 07, 2021, 03:35:37 AM »
Geoff,

The taper does not look all that steep, so why not the old method of offsetting the tailstock? An old method for an old engine. A taper attachment would be more convenient, but not all lathes are so equipped. Mind you, I have not looked at the newer lathes (bit behind the times), so maybe the functionality to offset tailstocks has gone the way of the dodo. I would mention if you use that method, to use the bell-shape center drills. The conventional conical centers will quickly wear into a bell shape (depending on severity of offset). But as they wear into the workpiece the job will keep getting slack between centers, so you need to be constantly taking up the clearance until it settles in.   

Oops, just realized you need a tapered i.d. as well. For that a taper attachment would be the cat's whiskers. Having a steady rest even slightly off center just wiggles the work out of the chuck (personal experience). Oh well, scratch that idea.

-Doug

Offline Georg49

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Re: How would you make this tapered column for the Williamson engine
« Reply #9 on: January 07, 2021, 11:42:35 AM »
Geoff,
thanks for your kind comments. Making the column was a work of patience, with tons of swarf and more than 95% weight loss. Two photos of the finished article.
Regards George

Offline steam guy willy

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Re: How would you make this tapered column for the Williamson engine
« Reply #10 on: January 07, 2021, 05:15:01 PM »
Hi ALL , Looking at the casting at the top post , I was wondering why the flutes don't reach the top and bottom all the way round  ?!! unless of course this is how the prototype was built and so this is an accurate depiction ?

Willy

Offline Jasonb

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Re: How would you make this tapered column for the Williamson engine
« Reply #11 on: January 07, 2021, 05:43:48 PM »
I expect the pattern was made with a router and the maker just stopped the cuts short. around the openings. The original etching that it is likely taken from that had the Benson engine on the same page shows that the full size did not go all the way either

Offline Mcgyver

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Re: How would you make this tapered column for the Williamson engine
« Reply #12 on: January 08, 2021, 12:33:22 PM »
Nice work George.

Making that might just be the impetus needed to get one of those high resolution resin printers (prints to about .001" irrc) and then lost wax cast it in AL.

Offline Chipswitheverything

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Re: How would you make this tapered column for the Williamson engine
« Reply #13 on: January 08, 2021, 02:52:05 PM »
George, highly impressed by the meticulous work shown to achieve the fine column, and by the beautiful engine that is the final result.  Dave

Offline Don1966

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Re: How would you make this tapered column for the Williamson engine
« Reply #14 on: January 08, 2021, 04:50:59 PM »
Awesome work and a beautiful engine George....  :Love:


 :cheers:
Don