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The Workshop Progress Thread 2020

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gary27/05/2020 20:18:21
78 forum posts
24 photos

lovely job Jason, as usual,

Nick Clarke 328/05/2020 15:48:08
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26 photos

Only another small step - having made a crank handle a couple of days ago and tried to cut a 25mm x 1.5mm thread - the first time I have tried screwcutting on this lathe. I now have a very tired left arm and an appalling failure of a thread.

Bit down at the failure I reset the change wheels for fine feed and noticed that when I had removed them the key on the mandrel gear had stayed in the gear so the one I had set up for threading was only held by the pressure of the retaining screw.

While it looked ok running light, under threading pressure the gear slipped from time to time - hence the intermittent movement of the saddle and the threads that blurred into one another!

I couldn't have happened on my Drummond with pins in the gears I suspect.

Anyway, having a look through Neil's mini-lathe book I realised out of the four projects he describes I had made or bought 3 but not the end mill holder.

So todays' positive progress is 10 minutes drilling, reaming, drilling and tapping a blank end arbour in the drawer. But it all counts and it cheered me up anyway. Just waiting for the steel for the drawbar.

mill holder.jpg

Edited By Nick Clarke 3 on 28/05/2020 15:53:24

Ron Laden30/05/2020 07:22:27
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Posted by JasonB on 26/05/2020 18:59:13:

Thank's Nick, got it more or less back together today after painting and although my balls did go round and swing out they were a little erratic. Think I need to get a second Mamod drive belt as it is a bit too much of a stretch for a standard one. Only time I used the collet chuck on the lathe was to hold the 3/16" stainless balls to drill the 1mm holes. Did use collets in the spin indexer for some jobs like making the 2mm A/F M1.2 nuts you can see.

But pleased that it seems to be running OK at the moment and need to resist the temptation to play with it when I should be working on the base. Just resting on the 1-2-3 blocks and less than 5psi showing on the comp regulator and no ball action!

Morning Jason, how is the base coming along not that I,m pushing (yes I am) winkcan't wait to see it finished.

Ron

JasonB30/05/2020 07:36:30
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Just doing the plumbing

Iain Downs30/05/2020 20:41:21
649 forum posts
570 photos

Nothing as interesting/pretty as most of you, but today was a tools day.

And end stop for the vice

tools vice end stop.jpg

wingnuts secured with that most ancient of fixings - superglue ...

This in turn used to make another chuck key for my 4 jaw

tools 4 jaw chuck key.jpg

Which I will use when making my eccentrics, having seen people use two chuck keys to great effect when centring a 4 jaw.

Iain

JasonB01/06/2020 19:07:53
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I got the exhaust pipe done on my Filer and Stowell engine yesterday and took it for a spin this morning.

Could do with a slight adjustment to the valve rod as if you watch towards the end you can see that the inward stroke of the piston is a bit stronger than the outward when it is running slowly. And if you can bear to watch all the way you will see the jumping balls as I'm waiting on a second belt, the one fitted is too short and putting a lot of load on that thin pulley spindle. Apart from that I'm quite pleased with how it turned out.

duncan webster01/06/2020 19:23:30
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2590 forum posts
33 photos

Quite pleased? I'd be absolutely delighted!

I've just made the same part 3 times, first just wrong, second mirror imaged, third time lucky. Fortunately it was a fairly simple bit.

Jim Nic01/06/2020 20:52:34
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244 forum posts
149 photos

Lovely runner again Jason and a lovely looker too.

I have used Mamod drive belts on a couple of governors and find that they are not very smooth running. I put it down to the fact that they are in effect long thin springs and so can react to varying loads from say bouncing balls or momentary tightening of the drive shaft by stretching and slipping rather than continuing to drive the governor. When I get a round tuitt I intend to try and find a different drive belt material.

Jim

Ron Laden02/06/2020 06:45:20
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1921 forum posts
367 photos

What can one say that is just superb Jason you should be very proud of that one and what a sweet runner, excellent it really is yes

The base is very nice to, I do like the way you have run the top finish pattern diagonally and parallel with the engine thats works well with the eye.

Great stuff smiley

Ron Laden02/06/2020 07:17:28
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1921 forum posts
367 photos

Jason have you considered Solid Nitrile Rubber Cord for the drive belt it's available in 1.00 mm diameter upwards. I would have thought it would be perfect for the governor drive.

Just a thought.

JasonB02/06/2020 10:10:22
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May give rubber a go but the Mamod one worked well on the RMC I did over Xmas and it's easy to join & break.

mechman4802/06/2020 12:33:37
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2663 forum posts
410 photos

Superb Jason. Paint job is top notch, do you use rattle can or mini spray gun ? having slow progress with my beam engine, some parts don't seem to be correct size/fit even though made to drawing dimensions & checkout with mic'... dont know... will step back for a day or two & get the grey matter into thinking mode... thinking .

George.

JasonB02/06/2020 12:56:33
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Although I have quite a few airbrushes and small guns I tend to just go for rattle cans these days. Usually pop into Halfords and pick a colour I like but due to lockdown went for a colour off a chart rather than going by a web image, this is Pale Roundel Blue in QAD ( Quick air dry) 1K with 90% sheen over white primer.

Right from when I first started drawing out this engine I had pale blue in mind and this came out well. next will be Kawasaki Green!

Edited By JasonB on 02/06/2020 12:58:02

JasonB07/06/2020 16:58:08
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I've made a start on the next engine, loosly based on a 1946 Thompson model engine.

mgnbuk07/06/2020 17:48:24
766 forum posts
60 photos

A frustrating weekend in the garage / workshop for me.

I volunteered to make a chuck adapter for one of my wife's work colleagues, who dabbles in wood turning. His lathe has an M24x3 spindle nose with 24mm register & he wants to fit a chuck with an M33 x 3.5 thread & 33 mm register. There are M33 to various nose thread reducers available but not to M24 x 3, which doesn't appear to be a popular size.

First trip-up was yesterday afternoon, when the lathe inverter refused to start up again after a coffee break - Fault Led illuminated. This is an ancient Toshiba inverter that was used and obsolete when I was given it, probably around 20 years ago so I can't really complain. A quick check with a basic multimeter showed balanced motor phase winding resistances & no obvious shorts to earth, though I need to bring my insulation tester home to be sure. I have a number of suitable NOS inverters in storage, but was uncertain whether or not to reform the capacitors before use (they have been is storage for several years) - a bit of researching suggested it might be wise to do so.

Tried the lathe again today & it worked ! Got the part to the stage of cutting the M24x3 internal thread & trip-up number 2 came along - the 34 tooth gear I bought to use with the Myford QC gearbox couldn't be fitted, as the gear quadrant would not rotate far enough (hit the end of the slot). A quick check found that I have all the gears required to cut a 3mm pitch thread with the "official" metric conversion set for the the Myford QC gearbox - but not the spacer to clamp up the gear on the gearbox input shaft. Got one on order from Myfords now. I tried to run the lathe to check how the gear train sounded under power (seemed OK by hand), but the inverter faulted out again.

So I lashed up a 240v to 55v-0-55v transformer & put 55v into the NOS Trend inverter for an hour, followed by 110v for an hour and a half (the drive came to life on this reduced supply), then 240v for an hour. No problems so far, just need to fit it after checking the motor out. I'll put switches on this one to control the spindle direction - the Toshiba was just linked up to sit at a constant 50hz forwards on power-up.

Nigel B.

Ron Laden08/06/2020 07:15:54
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Posted by JasonB on 07/06/2020 16:58:08:

I've made a start on the next engine, loosly based on a 1946 Thompson model engine.

Morning Jason,

Looks like another shapely engine is on its way, is that an aluminium cylinder.

JasonB08/06/2020 07:27:12
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Hi Ron, The original had what you see there all cast as one in aluminium, I did think about hacking it out of a solid bit of 6082 on the CNC but in the end opted for a silver soldered fabrication so what you see is all steel. Like the original there will be a cast iron liner and I will also use CI for the cylinder head rather than a bronze casting.

This is an original (or Bob herder kit)

And where I'm at with the drawing.

render.jpg

Ron Laden08/06/2020 07:43:48
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1921 forum posts
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Interesting Jason, I like the way the valves are driven via the gears and the pushrod, is it sized to your favoured 24mm bore.

Re having a cast iron cylinder liner, is steel not good for cylinders hence having a liner.

Will follow with interest.

JasonB08/06/2020 07:57:18
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The cam has not been added yet, the gear just keeps the cam follower from rotating as it runs against the side of it. yes 24 x 24 rather than 1" x 1" of the original.

I could have gone for steel cylinder with a cast iron piston running in it much like a lot of engines do but if there were any distortion due to the soldering the liner will be round.

DiogenesII08/06/2020 08:00:07
112 forum posts
46 photos

That Thompson really is an interesting little engine - I can see why you'd want to model it. I'd guess that economy was the main driver of the design, but there's something very pleasing about it.

Nice, Look forward to seeing it come together.

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