« previous next »
Pages: [1] 2 3 ... 6   Go Down

Author Topic: Scott Vacuum Engine......  (Read 106691 times)

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Scott Vacuum Engine......
« on: October 25, 2014, 10:27:27 AM »



Introducing Scott. Another of my orphan engines.

Arrived a couple of years ago. Been patiently waiting in the cupboard. 

Never run. (I don't think)........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/P1040525_zpsdcaa545b.jpgScott Vacuum Engine......


Badly packed, on top of the wad of drawings. Which were penetrated by the crankshaft.......  :bang:

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/P1040537_zps0331356d.jpgScott Vacuum Engine......


The shaft was bent, and flywheel distorted.
Rather proud of myself, at the time. I made a ballrace nudger. Which got it back, to within a couple of thou'.  :thumbup:

As it arrived. It was impossible to screw the valve mechanism together, tight enough........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/P1040535_zps89ff6618.jpgScott Vacuum Engine......


I dimpled the cross shaft, for the grub screw. Then made a temporary return spring........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/P1040529_zps088fa15a.jpgScott Vacuum Engine......


No joy! The shutter arrangement is much too light n floppy. Had a few pops, only.

After I'd caught my finger in the guillotine, for the third time. I decided it was time for some mods.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/P1040533_zps4a5a9bc6.jpgScott Vacuum Engine......


So......

The engine part is fine. The valve part is 'orrible.

I need some info, as to which is the best system to get the flame safely into the cylinder, at the correct time.

Some systems are eccentric driven, rather than a cam. I guess that is for quicker open/ close action.
But an eccentric will give positive motion, in both directions.

I can visualise a push/pull or twisting rod, along the side. How does it turn the corner, to the port?

Anyone any ideas? Crap o cad/ pics/ vids, gratefully accepted.

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline tom osselton

  • Hero Member
  • *****
  • Posts: 1301
Re: Scott Vacuum Engine......
« Reply #1 on: October 25, 2014, 06:03:22 PM »
Here is one by bogstandard
http://www.modelenginemaker.com/index.php?topic=158.0

One site said they made the graphite valve come down so the flame doesn't have to go over it.
Logged

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #2 on: October 27, 2014, 06:35:58 PM »
Quote from: tom osselton on October 25, 2014, 06:03:22 PM
Here is one by bogstandard

Hi Tom. Thanks for the link!  :thumbup:

That particular valve train, is a very unreliable system.
I'm minded to Mod it, the same as my last project. The Bengs, Nick.....  Can't be any worse than it is!  :palm:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #3 on: November 07, 2014, 04:19:39 PM »
Progressing. Slowly........   :thumbup:


Roughed out a slot, in the c/i base...........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141028_150957431_zps9f80c258.jpgScott Vacuum Engine......


Milled a matching slot, and 4 retaining holes, in the hopper........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141030_115740497_HDR_zps6c3429f5.jpgScott Vacuum Engine......


Matched up, nicely........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141030_150126407_HDR_zpsfa729aab.jpgScott Vacuum Engine......


It needed a widget...... M3 thread in one end, 3/16" hole in the other, and a 9degree bend in between.

Turned the big end, and tapped m3. Held in the rotary table, at 9*, spot faced and drilled 3/16, down to centre.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_112237601_zpsd1e32f4e.jpgScott Vacuum Engine......


On to a 3/16" mandrel. Turn small dia........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_114512997_HDR_zpsab51b24b.jpgScott Vacuum Engine......


M3 studding. Turn radius........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_115457251_HDR_zps5268d833.jpgScott Vacuum Engine......


Couple of flats. Loctited, to the tubular operating arm........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_145150649_zps93a4dc13.jpgScott Vacuum Engine......


Bottom of stroke.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_144925712_zpsa26d2cf1.jpgScott Vacuum Engine......


Top.........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141106_144951748_zpsea4bff60.jpgScott Vacuum Engine......


I'm quite pleased, how it's gone together, so far.

I've (finally), read up the Poppin plans, and think the lightweight valve is the way to go.
Bought some 5thou steel shim. If I can cut it, and keep it flat. I might be in with a chance!

The present return spring is much too stiff. I've made a better action, with a small coil spring, under the cam arm.
But, I don't want to abandon the leaf spring, just yet.

Does anyone know where I can get a sensible length, of 1/4" x .012" spring steel?

Thanks for looking in!   :beer:

David D
« Last Edit: December 10, 2014, 04:21:53 AM by Stilldrillin »
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline PJW

  • Jr. Member
  • **
  • Posts: 53
Re: Scott Vacuum Engine......
« Reply #4 on: November 07, 2014, 04:43:07 PM »
Hi Dave, I am watching with interest, I know nothing about vacuum engines so its look and learn. It looks like it will be an interesting engine when you have it running.
Logged
Old Guys Rule the Dark Side of the Shed!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #5 on: November 07, 2014, 06:00:04 PM »
Quote from: PJW on November 07, 2014, 04:43:07 PM
Hi Dave, I am watching with interest, I know nothing about vacuum engines so its look and learn. It looks like it will be an interesting engine when you have it running.

Hi Peter.
I don't know enough about these things, either! With me, it's fumble and learn......  :scratch:

Did you see my last one? http://madmodder.net/index.php/topic,9661.0.html

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Pete W.

  • Hero Member
  • *****
  • Posts: 852
Re: Scott Vacuum Engine......
« Reply #6 on: November 08, 2014, 09:03:45 AM »
Hi there, David,

"Does anyone know where I can get a sensible length, of 1/4" x .012" spring steel?"

A bit of feeler gauge stock might do???? 
Logged
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #7 on: November 08, 2014, 03:49:40 PM »
Quote from: Pete W. on November 08, 2014, 09:03:45 AM
A bit of feeler gauge stock might do????

Pete.

You're right!  :thumbup:

Why didn't I think of that?   :doh:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline PJW

  • Jr. Member
  • **
  • Posts: 53
Re: Scott Vacuum Engine......
« Reply #8 on: November 08, 2014, 06:34:47 PM »
Just looked at your last engine Dave, it a little cracker!  well done!
I do like the look of this one though & look forward to seeing it running, keep up the good work.
Logged
Old Guys Rule the Dark Side of the Shed!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #9 on: November 09, 2014, 04:28:29 AM »
Thanks Peter!
Didn't enjoy the fumbling. Much too small n fiddly, for my old fingers. But, I love it now it's doing what it's supposed to do......  :thumbup:


Feeler gauges....... Hmmm.....   
Not given them a thought, for the past 20 years, or so. No need, for modern vehicles. 

Just been rummaging, in my old toolboxes........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141109_083004240_zps39ebb0b7.jpgScott Vacuum Engine......


What a nice trip, down memory lane!

The central one. For my first motorbike. Came from the Brighouse branch of Woolworths, 1960. Cost 1s 3d.

The lower one was bought for my brand new, 1965 BSA Lightning.

The top one, when I went metric. Around 1980.

I've got all the spring steel I need...... Thanks for the posts, and pm's Fellas! Much appreciated.   :beer:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline PJW

  • Jr. Member
  • **
  • Posts: 53
Re: Scott Vacuum Engine......
« Reply #10 on: November 09, 2014, 05:04:52 AM »
there is a piece of spring steel in the old VHS tapes, some have a plastic spring but mist have steel,

Peter
Logged
Old Guys Rule the Dark Side of the Shed!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #11 on: November 10, 2014, 02:41:21 PM »
Managed a few workshop minutes, this afternoon.  :thumbup:

Assembled. Then realised, I'd forgotten the leaf spring!   :Doh:

The little coil spring, saved the day.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141110_153917766_zps6d4fdd51.jpgScott Vacuum Engine......


Gave it a flick....... And it stuttered into life!!.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141110_151615909_zps2a7ca787.jpgScott Vacuum Engine......


You know that supreme moment.   
When the blood pressure goes sky high. And, all you want to do, is dance about, for joy.   :ddb: :ddb: :ddb:

It's A RUNNER!!!!    :D :D


At that precise moment, SOMEONE, was knocking on the door........ "Grandad"....... Didn't know what to do! I nearly burst!


I had a Little Helper, for the rest of the afternoon.......



I bet Steven Spielberg, never had such a helper.......



Love it!

David D



Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Kjelle

  • Full Member
  • ***
  • Posts: 178
Re: Scott Vacuum Engine......
« Reply #12 on: November 10, 2014, 03:23:09 PM »
Nice job!! Sounds like your little helper is a ray of sunshine, too!

Kjelle
Logged

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #13 on: November 12, 2014, 08:36:18 AM »
Thanks Kjelle.
She's a lovely, little bundle of happiness. Especially, around Grandad......   


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

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!  :palm:


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

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #14 on: November 15, 2014, 08:39:20 AM »
Showing the original "Poppin", shim valve arrangement. It's a bit vulnerable........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141111_113130293_HDR_zps69826932.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141115_130417515_zps897a27b6.jpgScott Vacuum Engine......



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!   :scratch:

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......  :thumbup:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 9100
  • East Sussex, UK
Re: Scott Vacuum Engine......
« Reply #15 on: November 15, 2014, 09:34:39 AM »
Quote from: Stilldrillin on November 12, 2014, 08:36:18 AM

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

David D

David,

The attached pictures may be of interest - it's Poco brand EDM graphite from my stash of things potentially (Pun intended  :ddb: ) to make electrodes from. POCO is a very fine grade of graphite for fine details
Logged
Andrew Mawson
East Sussex

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #16 on: November 15, 2014, 09:54:22 AM »
By, 'ek, Andy!  :bugeye:

Yer've got me attention, now!   :D

Switch to pm's, I think.......  :thumbup:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 9100
  • East Sussex, UK
Re: Scott Vacuum Engine......
« Reply #17 on: November 15, 2014, 09:59:00 AM »
David,

Tell me how much you want sawed off the (presumably) 2" piece, PM me an address and give Eric a donation in my name to the running of the site for what you think it's worth to you.

I ain't turning it down to 35 mm for you - my lathe is reasonably clean  :lol:
Logged
Andrew Mawson
East Sussex

Offline geoff_p

  • Jr. Member
  • **
  • Posts: 49
Re: Scott Vacuum Engine......
« Reply #18 on: November 15, 2014, 04:30:04 PM »
For smaller lumps of graphite, such as your valve-block, I use carbon-brushes from/for electric motors.  The local motor-repair shop keeps them up to about 1cm-square section by 4cm long, of which the braided wire connector ruins a cm or so.

Am currently using this material for big-end bearings on my experimental 4-T petrol engine, where they take an awful hammering.
Logged

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #19 on: November 26, 2014, 08:09:52 AM »
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.  :bang:

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.  :palm:

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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141120_094240588_zps5abe358b.jpgScott Vacuum Engine......


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........

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141118_143044988_zpscec04d7b.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141118_144102403_zpscb32920a.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141119_134735677_zps331693db.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141119_150004745_zpsa5d8b97b.jpgScott Vacuum Engine......


There you go.......

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141119_153258087_zps109954dd.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141121_140012713_zps7cc5da88.jpgScott Vacuum Engine......


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

http://i110.photobucket.com/albums/n95/Dayjo/Return%20Album/IMG_20141125_111058483_zps4d99d199.jpgScott Vacuum Engine......


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

Thanks for looking in!  :thumbup:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 9100
  • East Sussex, UK
Re: Scott Vacuum Engine......
« Reply #20 on: November 26, 2014, 08:18:54 AM »
Nice work  :thumbup:

I like the trick of off setting the weld  :bow:
Logged
Andrew Mawson
East Sussex

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #21 on: November 26, 2014, 08:26:39 AM »
Thanks Andrew.

I'm just pleased, I thought of it. Before I started machining!  :palm:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Joules

  • Hero Member
  • *****
  • Posts: 1320
Re: Scott Vacuum Engine......
« Reply #22 on: November 26, 2014, 09:47:20 AM »
Lovely bit of work there David, always fancied one of these engines...  Must pull my finger out one day and make a start on one....................................................................................and finish it  :palm:

What mill do you have ?
Logged
Honour your mentors, and pay it forward.

Offline Stilldrillin

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 4972
  • Staveley, Derbyshire. England.
Re: Scott Vacuum Engine......
« Reply #23 on: November 26, 2014, 04:43:02 PM »
Thanks Joules! 

The mini mill, is the one in my avatar.
A Chester Conquest. Modded, with R8 spindle, and belt drive etc. Works for me!  :thumbup:

David D
Logged
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline dawesy

  • Sr. Member
  • ****
  • Posts: 252
Re: Scott Vacuum Engine......
« Reply #24 on: November 28, 2014, 02:56:42 AM »
Very nice. Good work.
Just as a thought if you ever need to do another is seamless pipe. I used some sch10 316L when making an exhaust manifold. It's a bit more expensive but has no seam to worry about.
Logged
Lee.
wishing my workshop was larger :(
Pages: [1] 2 3 ... 6   Go Up
« previous next »