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The Workshop Progress Thread 2019

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JasonB21/01/2019 20:41:38
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Yes quite a few particularly as the internal "web" meant having to cut from both sides.

Did all the straight lines and then the arcs that relate to the top curve first at one setting.

Then flippe dover to do thetwo inner part depth 6mm dia cuts. After that reset the plate for the larger side radius, I put two 6mm holes in to make it easy to locate the parts for the rest of the cuts.

Ron Laden21/01/2019 21:04:45
859 forum posts
121 photos

Yes I thought they must have taken quite a bit of setting up, turned out really well though.

Ron

duncan webster21/01/2019 21:34:26
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Posted by John Haine on 20/01/2019 10:11:37:

Having lugged 7 bags of sugar (or its equivalent in cast iron bar) home from Ally Pally for my Synchronome bob I needed to at least square off the ends and drill for the rod. I did't fancy trying to mount it in the lathe - 7 inches long and over 3 diameter and weighing that much, and not able to use a fixed steady on the as-cast circumference. Only option was the mill, I decided what I really needed was a very large Keats angle plate but no idea where to get such a thing. So dtarted to look at my collection of angle plates and found this one:

img_20190119_180456678.jpg

Bought for a pittance from a market stall years ago, it's ground square on the inside edges as well as the outside and ends. Work of a few moments to clamp to the mill table.

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That's the bob sitting on the swarf tray btw.

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Couple of G clamps to pull the cylindrical surface against the faces of the angle plate and "Bob's your uncle" you might say.

I thought you were supposed to use a WW1 surplus 16 pounder artillery shell!

duncan webster26/01/2019 20:22:50
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1860 forum posts
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Just to show that I do actually make something from time to time, here's a few shots of making the motion plates for my latest loco. Apart from marking the outline to saw the rough blanks off the scrap 5mm plate all done by dead reckoning with the DRO

Machine to overall outside profile

Drill and bore the 4 internal radii

saw out the waste (the part complete cut should have been left till later, spotted this half way through thankfully)

machine internal profile to size

finalise outside profile (no photo sorry)

machine slot for radius rod

spot and drill mounting holes.

 



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Edited By duncan webster on 26/01/2019 20:25:02

Edited By duncan webster on 26/01/2019 20:28:45

Edited By duncan webster on 26/01/2019 20:29:47

JasonB27/01/2019 18:35:11
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Managed to get a bit more done on the IF Allman. The top of the inlet valve block, hot tube and burner ring are now done.

Also made up a banjo fitting for the gas valve

Assembled on the engine

Also made some progress on the Forest inspired flame licker

J

Ron Laden28/01/2019 06:43:04
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121 photos

Morning Jason, looking good, seems you have made quite a bit of progress and working on two types of engine along side each other at the same time is even more impressive.

Thinking about the flame licker and you explaining that everything needs to be very free running how do you deal with the piston. I would imagine that it differs in some way from the norm i.e. providing a seal but little in the way of friction or drag along the stroke..?

Ron

Edited By Ron Laden on 28/01/2019 06:43:52

Edited By Ron Laden on 28/01/2019 06:44:39

JasonB28/01/2019 07:27:19
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Ron, the cylinder was first honed with a brake cylinder hone and then lapped down to 1000g with silicon carbide powder/oil.

The piston was then honed until it just started to enter the bore and then was lapped the rest of the way.

As these engines don't have a lot of power I lapped it a bit looser than you would an IC aero engine but not so far that you loose compression.

Ian S C28/01/2019 10:23:39
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7190 forum posts
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On the cylinders I make for hot air motor (what ever type), I lap the piston after lapping the bore until the piston will just slide through the bore under its own weight, and if the end of the bore is blocked off the piston should virtually stop, if it keeps going, make another piston its too loose.

Ian S C

Jim Nic30/01/2019 17:16:29
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80 photos

I’ve not been well for a couple of months so there has been less progress on the Overcrank engine than normal.

This is the first engine I have built without the benefit of a build log or construction notes for guidance. My plan was to make the crankshaft next but luckily I had a close look at the drawings before I did and found that the valve eccentrics and crank centre bearing were on the shaft between the 2 throws.

eccentric 3.jpg

The bearing could have been made as a split shell but I couldn’t see how to make the eccentric sheaves work with a join in them. So the only way seemed to me to make them as normal

eccentric 2.jpg

and assemble them on the crankshaft before assembling and pinning the journals.

eccentric 4.jpg

Happy days, the valves seem to move as they should so now it's back to the plan and build the crankshaft.

Jim

JasonB02/02/2019 19:51:11
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Carrying on with the plumbing for the Allman I have been working on a twin needle valve assembly to hopefully control the gas better than the commercial valve I used for the Robinson.

In the photo below gas will enter via the 1/8" BSP thread half way up then go down to the engine feed (already puimbed in copper)and up to the burner. The two nuts on teh left will be the gland nuts for the needles and will be operated by small [s]hand[/s] finger wheels.

Just finished cutting an M10 x 0.75 thread to make an adaptor that will replace the stainless steel end of the smallest Sievert burner so I can screw into a 1/8" BSP elbow. You can just see what goes inside it top right.

Andy Carruthers02/02/2019 20:36:23
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Hats off to you all!

Far beyond my capability - I did manage to make a dovetail tool holder for my QCTP without breaking anything though, which is an schievement in itself

JasonB03/02/2019 10:39:57
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The modified Sievert burner seems to be working OK now that I have also reduced the incomming air by pressing on a sleeve with just two 0.75mm holes.

mechman4804/02/2019 18:47:03
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2225 forum posts
378 photos

A bit more progress on my Boxer twin oscillator, been on the back burner for a while.... discarded the first flywheel as it was too big in OD & ID ( from another project ), made a new one...

flywheel.remade.jpg

so far...

32.osc.flywheel update.jpg

George.

Ron Laden05/02/2019 07:39:37
859 forum posts
121 photos
Posted by JasonB on 03/02/2019 10:39:57:

The modified Sievert burner seems to be working OK now that I have also reduced the incomming air by pressing on a sleeve with just two 0.75mm holes.

The burner does look to be working well in the way the flame pattern heats up the top 2/3rds of the hot tube. From an earlier picture the burner assy looks to be housed in a vertical housing next to the cylinder, I guess there must be some kind of inlet valve arrangement at the top of the tube. Also is the purpose of the hot tube to maintain a constant level of heat rather than just having a burner. Interesting how some of these engines work.

Ian S C05/02/2019 09:01:38
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7190 forum posts
227 photos

Jason, Is there some obstruction in the burner design that prevents a complete ring of burner holes? Not important as the burner seems to be doing its job well, how does it go in the chimney.

Ian S C

JasonB05/02/2019 09:19:49
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Ron, I'll section a few part sin Alibre and explain how the hot tube goes together later.

Ian, yes the ring of fire does not go all the way round as I left a section solid to take a grub screw so the position of the ring can be adjusted, altering the height will advance or retard the ignition. Chimney will be just above the top of the ring.

JasonB10/02/2019 19:39:06
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14642 forum posts
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just fancied some simple turning this weekend so got a few bits and pieces done for what I likely to be the next engine, as an idea of size the long rod at the top is 1/8" dia.

Also did the flywheel, by the smell of it and the curly swarf it would seem to be SG Iron.

Ron Laden11/02/2019 13:35:44
859 forum posts
121 photos

Steady on Jason, I cant keep up, you have two different engines well under way and your now making parts for a third (you will probably say there is another in the pipeline also).

Your work rate and progress is something else, I dont know how you cope with it but it certainly is impressive to say the least..smiley

Ron

Howard Lewis11/02/2019 14:33:57
1694 forum posts
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Have just (successfully, I hope) completed a mechanical jigsaw. It was a Cobbler automaton. Unfortunately, at some time it had been subjected to great forces, and then half repaired.

Before coming to me the ruined motor and integral gearbox had been replaced, but nothing had been done about the bent actuating rods, and a foul between the over long screw that retained the cam follower to the transverse lever. (Presumably part of the "repair" ).

The frame and the lever were slightly distorted, as was the cam (which seemed to been fitted the wrong way round. (Grubscrews inside and almost inaccessible), resulting in the follower being packed out to mesh with the follower with a number of washers.

At least, after clocking on an arbor and a combination of levering and impacts got it true within 0.008" Then turned up a new spacer so that the cam engaged the follower.

Not knowing what should be present, or how everything should be arranged resulted in a lit of village blacksmithing, followed by a lot of trial and error.

Two adjustable rods with ball joints (received bent, but straightened) could each be fitted in two holes, and inboard or outboard. When assembled, and with the rods adjusted, as i thought correctly, it worked until the back was fitted! Moving the outer ball jointed rod inboard decreased the foul, but did not eliminate it completely, so the plastic back had to be carved away, locally.

A slight rerouting of the wires away from the moving parts and it now works, more or less as I would expect.

So hopefully, when collected, I shall receive a donation for my M E Club, and we shall all be satisfied.

Howard  Expletive and Emoji deleted!

Edited By Howard Lewis on 11/02/2019 14:34:54

duncan webster11/02/2019 20:09:39
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1860 forum posts
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A bit of progress on motion plates, how can it take so long to drill and tap 12 holes? Not the easiest thing to hold together with the bits in the right place I supposemotion brackets assembled (small).jpg 

Edited By duncan webster on 11/02/2019 20:10:09

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