Author Topic: A Beginner's First Engine (Single-acting Oscillator)  (Read 23551 times)

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #105 on: March 03, 2019, 01:34:36 PM »
Ah... must have had an impatience-based blind spot that cost me 50 quid.

On ebay all I saw were the kind of cylinder hones with three stones and they all seemed to be too big for my purposes. Never mind... my next engine will have twice the bore and I'll look more closely when it comes to cylinder hones.

The Sealey catalogue sounds good. I love leafing through catalogues, dreaming about having room for all the tools that are in them...

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #106 on: March 03, 2019, 11:34:07 PM »
Next up was the piston. In Steve's plans the piston, con rod and big end are all machined from one piece of brass, and the forms are all left cylindrical. I also made mine from a single piece of brass, but added a couple of details, just for the look.

Some curves at the ends of the con rod, cut with my new round-tipped carbide profiling tool (which I already love):



And a flattened big end:



I ruined my first effort by making it too short. No idea why it happened, but there we are. I gave it to my dear lady to put on her keyring. The second effort seems fine. I had been quite anxious about making the piston, thinking that it would probably be beyond me to make a piston and cylinder that fit together. However, it was surprisingly easy, just coming in slow on that final dimension with a fine grit paper, a flat stick and some oil. Both pistons (the reject and the good one) create a good vacuum in the cylinder, springing back up when pushed down, or making a nice 'plup' sound when pulled out with a thumb over the other end of the bore. A good step forward:





That done, I started on the crank. A slice of bronze was marked out and drilled:



Now, in the plans the crank is just a circular disc, but I have always liked the look of the crank on Ade Swash's 'Cornish Blue Pepperpot Wobbler'

https://www.youtube.com/watch?v=nIKJXt2b8yQ

so I thought I'd have a go at making something similar. I sawed, filed and sanded it by hand, then milled the groove on the rotary table with a round-nosed endmill. The inherent inaccuracies in my bench work caused the hole for the crank pin to end up slightly out of alignment (i.e. nice and perpendicular but not quite in the right place). However, the two holes are the correct distance apart and I reckon that once the thing is assembled it will be hidden by the big end and even I won't notice it. Overall, I'm pretty pleased with it:



Here it is with the 3mm silver steel crank pin Loctited ('Intersealed') in place:



And here jury-rigged on the end of the main shaft, just for fun:



Both the main shaft and the crank pin will be cut to the correct length at the end of the build.

gary

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13860
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #107 on: March 04, 2019, 12:24:16 AM »
I like that crank too Gary. Ade's engine in a fine looking oscillator too. I can see why you like it.

Bill

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #108 on: March 04, 2019, 12:41:05 AM »
Yeah - these little touches can make all the difference.

 :ThumbsUp:

Offline Gas_mantle

  • Full Member
  • ****
  • Posts: 1365
  • North Yorks - UK.
    • My Youtube channel
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #109 on: March 04, 2019, 12:49:26 AM »
Its looking good  :)

Not long now before we can see it running on the hot stuff.

Are you going to invite us all round for a cheese and wine evening to celebrate the inaugural steam up  ;)

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #110 on: March 04, 2019, 12:56:09 AM »
Are you going to invite us all round for a cheese and wine evening to celebrate the inaugural steam up  ;)

Of course - but it will be at your own risk. The boiler hasn't been inspected, so it's likely to explode   :wine1: :Mad:

Offline Tennessee Whiskey

  • Full Member
  • *****
  • Posts: 3781
  • Springfield, Tennessee. USA
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #111 on: March 04, 2019, 01:01:45 AM »
Fireworks, wine, cheese, what more could you ask for?  :Jester: Looks great gary.

Cletus

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #112 on: March 04, 2019, 09:42:41 AM »
Pressure, scalding heat, metal parts at high velocity, and alcohol.

What could possibly go wrong?

Cheers Eric  :ThumbsUp:

Offline JC54

  • Full Member
  • ****
  • Posts: 126
  • Grantham, Lincolnshire, UK
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #113 on: March 04, 2019, 06:46:12 PM »
Evening Gary, really like your piston/conrod, it took me 5 attempts to get mine as I wanted it. Have I led a sheltered life or is the turning tool that you used a common item? Enjoying your build, been there on this engine... but made a lot more mistakes... :embarassed: :old: :DrinkPint: John
When the Fun Stops,, Stop!

Offline bent

  • Full Member
  • ****
  • Posts: 790
  • Wet side of Washington State, USA
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #114 on: March 04, 2019, 06:52:29 PM »
That is a neat looking crank, may have to try that sometime - thanks Gary!

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #115 on: March 04, 2019, 10:50:33 PM »
Many thanks guys.

@ John - I'm not sure how common the round nosed tools are, but I'm already sold on mine having had them a few days. I got them from RDG tools.
There are still a few opportunties for me to make mistakes on this build - see my next post   :disappointed:

@ bent - thank you.. The credit goes to Ade Swash on youtube.

 :ThumbsUp:

Offline gary.a.ayres

  • Full Member
  • ****
  • Posts: 1297
  • Isle of Skye & sometimes France
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #116 on: March 05, 2019, 12:13:09 AM »
Pulleys.

With a pulley, an engine bespeaks connectedness and possibility. It is not a closed system. Even a little half inch wobbler - which may never actually drive anything other than itself - takes on a more 'networked' aspect with the addition of a pulley. So, while waiting for some other bits and pieces to arrive, I set about making one.

Drawing inspiration from my new round-nosed carbide tools, I ordered two small round drive belts from an interesting company called Motionco. This was just to gauge the size of the pulley groove, which was just as well as I didn't think to order a sensible length and so ended up with the below, which are fine for sizing purposes but not much else. My bad.



The bigger of the two is far too big for this engine, and the smaller may be too small for the groove cut by the smaller tool. We shall see. I can always buy a belt somewhere between the two if I ever actually hook anything to the engine.

I started making a pulley out of aluminium bar (to contrast with the brass flywheel):



This came together quite quickly and was finished on the shaft with the flywheel, resulting in two wheels turning together with zero wobble:



Result!

Then disaster struck. Like a damn fool I impulsively decided to shorten the protruding length of the shaft you can see in the picture above by facing it (I know...). The tool caught the end and bent the shaft.  :ShakeHead: I took it apart and tried to salvage a straight piece, but to no avail. Two wobbly wheels until yesterday's order of more silver steel arrives, with me on tenterhooks until it does.

Bent shaft notwithstanding, today's progress:




Offline Gas_mantle

  • Full Member
  • ****
  • Posts: 1365
  • North Yorks - UK.
    • My Youtube channel
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #117 on: March 05, 2019, 12:29:05 AM »
That's a pain that you ruined the shaft, but I guess you can take comfort in knowing nearly everyone else has done the same.  :(

As for drive belts if yours are unsuitable others can be bought here :-

https://www.glrkennions.co.uk/belting.html

https://www.maidstone-engineering.com/materials/misc-materials

Not sure how well the jointed GLR ones work on a tight radius though.

« Last Edit: March 05, 2019, 12:36:30 AM by Gas_mantle »

Offline crueby

  • Full Member
  • *****
  • Posts: 18554
  • Rochester NY
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #118 on: March 05, 2019, 12:34:00 AM »
Oh yes, been there, done that!  Great progress still!


 :popcorn:

Offline b.lindsey

  • Global Moderator
  • Full Member
  • *****
  • Posts: 13860
  • Dallas, NC, USA
    • Workbench-Miniatures
Re: A Beginner's First Engine (Single-acting Oscillator)
« Reply #119 on: March 05, 2019, 12:36:12 AM »
What a bummer Gary. Hope it left the pulley and flywheel bores undisturbed though.

Bill

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal