Author Topic: Scott Vacuum Engine......  (Read 51885 times)

fcheslop

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Re: Scott Vacuum Engine......
« Reply #30 on: November 10, 2014, 10:46:45 PM »
Nice one David :ROFL:
Dont know whats more entertaining the engine or the granddaughter  :ROFL:
Its nice as they get a little older and there mothers complain.Then I always simply say and who do they take after :naughty:
Not that I encourage them :mischief: or feed them Es or Bs or Iron Brew   :mischief:
Our granddaughter is now eleventeen  :censored:
Cheers and thanks as its cheered this grump up no end

Offline PJW

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Re: Scott Vacuum Engine......
« Reply #31 on: November 11, 2014, 12:04:59 PM »
Nice one dave, glad to see it going!
Old Guys Rule the Dark Side of the Shed!

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #32 on: November 12, 2014, 09:21:14 AM »
Thanks Frazer, Peter.  :ThumbsUp:


So much for the "wonderful" idea, of the original graphite valve, lubricating the piston and bore. No need for other lubrication! :noidea:

The vacuum chamber condensation, turned to rust, overnight! 

Another, fun d mental flaw? I seem to get a lot of them, in my rebuilds! Sheesh!  :facepalm:


Anyone know, where I can source 35mm dia graphite in the UK. At sensible cost?  :shrug:

David D
« Last Edit: November 12, 2014, 01:46:51 PM by Stilldrillin »
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

fcheslop

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Re: Scott Vacuum Engine......
« Reply #33 on: November 12, 2014, 05:37:48 PM »
I know youre a Yorkish shire man and I havna checked the price but can recommend Noggin ends graphity stuff its very good quality and I never had a prob with it unlike that jewellers stirring rubbish
Or maybe more appealing is there no toolies down youre way using edm machines you maybe just be able to snaffle a bit if you give it the hard up pensioner routine  :o

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #34 on: November 12, 2014, 06:23:05 PM »
Yorkshire, Frazer?!! :hellno:   :cussing: ........ I'll see you, later......  :Argue:

Don't mind paying. Sensibly...... Noggin's sizes only go up to 1" dia.  ::)

Never come across, an edm machine......  :ShakeHead:

Today, I modded the shutter set up, slightly. Had it running at around 150rpm. Until the condensation built up.  :(
Guess that's why I've heard of starting 'em, full of warm water.......  :thinking:

David D

David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

fcheslop

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Re: Scott Vacuum Engine......
« Reply #35 on: November 12, 2014, 07:34:47 PM »
Sorry I forget and you know Iv to wiggle under the fences at customs .Not a pretty sight  :ShakeHead:
EDM= sparker
Would a bit of bronze no do :o second mortgage maybe needed.
She is coming on canny soooooo the big question :Jester:
cheers

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #36 on: November 15, 2014, 01:42:24 PM »
Showing the original "Poppin", shim valve arrangement. It's a bit vulnerable........




So, I made a temporary guide arrangement. Shim, loose on the actuating arm.........





No chance, so far, of a piece of graphite.  :(
I thought this would do the job..... http://www.ebay.co.uk/itm/300839376964?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Until I ran the mouse over, to zoom. It's made of dried leafmold!   :o

Guess it will have to be a brass piston. 

The stainless tube has arrived, to sleeve the cylinder. See last pic.

A piece of 8mm stainless plate is on it's way, for the port face.

Progressing. Slowly......   ;)

David D
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #37 on: November 26, 2014, 01:12:39 PM »
Progressing, steadily.

The runs I managed to film, were the only life I could coax out of this engine!
Days after, it still hadn't run again.  :shrug:

Condensation left a dragging film, between piston and bore. Couldn't get the engine to spin.
Also, all other internal cast iron areas had a film of rust.

Seems a pity, to break up this well matched partnership. But, it's time to go, rustless!




Bought a length of 35mm stainless steel exhaust, 1.5mm wall thickness.
The inner seam was some 8thou deep. So, I set it over in the chuck jaws, using a piece of 10 thou steel sheet. To ensure a deeper cut over the seam area.

Clocked parallel to carriage travel........




Cleaned up both ends, leaving a witness........




I could then bore, concentric to each end.......




Then, turn the o/d concentric to bore.......




There you go.......




Open up bore to +.002" on sleeve o/d........




Loctite in place. And skim the ends........




Now, waiting for my pal Dave, who's a whiz with a bore grinder.  ;)

Thanks for looking in!  :ThumbsUp:

David D
« Last Edit: November 26, 2014, 01:17:41 PM by Stilldrillin »
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #38 on: December 04, 2014, 08:08:52 PM »
Now, waiting for my pal Dave, who's a whiz with a bore grinder.  ;)

Here we go...... Arrived, this evening.  :cartwheel:

Lovely bore........




Thanks Dave! Yer a gem:praise2:

David D
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #39 on: December 04, 2014, 10:17:18 PM »
Time to tackle the cylinder head.
From a piece of 8mm stainless plate, 100mm square. (Room for a spare. If it all goes pear shaped).   :(

It was at, (only), this point, I realised I am not as young as I would like to be........




Several rests, and the following day. It was free.......




I usually knock the corners off, by friction turning. In my mini lathe....... No chance!  :ShakeHead:

So, I mounted it in the r/t. And milled it roughly, round.........




Normal lathework followed. Finally finishing the o/d between blocks.......




The new head fits as a cap, over the cylinder flange. Giving .150" extra headroom, for a thicker graphite piston crown......




Looks rather nice, like this. Seems a pity to go poking holes into it.......




Twin port! Because the new shim blade, was occasionally sucked into the full width original port........




Inside.......




Much shorter inlet passage. Less heat absorbed into the head. Mebbe........




Shouldn't rust in there, now........




Thanks for looking in!   

David D
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Online Jo

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Re: Scott Vacuum Engine......
« Reply #40 on: December 05, 2014, 11:47:46 AM »
Hacksawing through thick stainless  :( I am surprised that it did not do nasty things to your hacksaw blade as well.

But it was worth it in the end  ;)

Jo
Usus est optimum magister

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #41 on: December 05, 2014, 01:02:35 PM »
Hacksawing through thick stainless  :( I am surprised that it did not do nasty things to your hacksaw blade as well.

But it was worth it in the end  ;)

Jo

I think the total was 5 blades, Jo. Some of them, pre used.  :embarassed:

But, it's ok. I'm a Pensioner. I can afford to buy more........  ;)

David D
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #42 on: December 09, 2014, 07:54:47 PM »
Steps forward...... Steps backward. But, overall......   

Mounted the original c/i piston, on a handy piece of curtain pole, and reduced to fit the new bore.

About -5thou from original.......




Assembled. But couldn't get the engine to spin freely. Seems the open end of the bore is a little tight.   

So...... Turned another length of curtain pole, to a sliding fit. (After sanding off the fuzz)........




Coated in fine grinding paste. And oscillated for 30mins, or so.......




Seems Dave has gripped on the end of the cylinder o/d, in his industrial machine, and triangulated it!

Re assembled, again. Piston/ bore, dry, no oil. shouldn't pick up. Just a quick test run.

Twin temporary burners, this time.......

<a href="http://www.youtube.com/watch?v=I0pQ9PcWSTU" target="_blank">http://www.youtube.com/watch?v=I0pQ9PcWSTU</a>


Now, I'm confident to carry on modding, to finish, as planned.  :D


Except......

An hour after running. The piston was stuck in the bore. Again!

The dreaded, condensation rust.........




Sheesh........




Pleased, the lap is still mounted in the chuck. I can polish the bore, for the new graphite piston.

Winter's closing in, on old bones. Not much will be happening this week.

Thanks for looking in!

David D
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

fcheslop

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Re: Scott Vacuum Engine......
« Reply #43 on: December 22, 2014, 08:04:33 PM »
Nice work marra,  Any progress or it maybe a little too cold down youre neck of the woods.
cheers

Offline Stilldrillin

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Re: Scott Vacuum Engine......
« Reply #44 on: December 22, 2014, 11:01:53 PM »
Nice work marra,  Any progress or it maybe a little too cold down youre neck of the woods.
cheers

Thanks, Frazer!
Been a little slow, recently. And cold!

Also, Small Person, needing delivering/ retrieving, from school. Then being entertained, for a while.  :Jester:  Nice..... But.......  :shrug:


Frankly, I'm not sure anyone here, is much interested in what I do, any more.

Counting back, gives 6 postings of progress........ Only one comment, from Jo. (Bless Her)!

The posting on Modder, has the "same" hit count. Also, more questions/ discussions.

Wonder, if I've upset the Purists, who prefer to work strictly to drawings, only?


Anyroad! I've made and tested the shutter guide. Will assemble the pics, and little vid. Posting tomorrow. 

David D
« Last Edit: December 22, 2014, 11:08:12 PM by Stilldrillin »
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!