Author Topic: A Robinson from rejects.  (Read 35918 times)

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #270 on: March 09, 2018, 08:50:54 PM »
Wow that turned out nicely, I'm suprised how clear it machined  :)

Indeed....

Well done Jason.

Offline ettingtonliam

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Re: A Robinson from rejects.
« Reply #271 on: March 09, 2018, 09:16:15 PM »
Speaking of oiling, what if any were the arrangements for the hot air engine? Did it have a cylinder oiler and a lubricator on the crankshaft bearing? Oil holes in the various links and rods?

Richard

Offline Steamer5

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Re: A Robinson from rejects.
« Reply #272 on: March 10, 2018, 08:40:47 AM »
Hi Jason,
 Just caught up. The taper on the conrod makes a big difference! A small change just seems to make things look so much more eye appealing!

The sight glass is pretty nice too!

Cheers Kerrin
Get excited and make something!

Offline Ian S C

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Re: A Robinson from rejects.
« Reply #273 on: March 10, 2018, 01:37:56 PM »
A full size motor And it's piston showing the oiler.
Ian S C
         

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #274 on: March 10, 2018, 04:29:24 PM »
Drip oiler finished



And a couple of cups for teh main bearings, not sure about the size of the hex, may mill it down by 1/16"


Offline Craig DeShong

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Re: A Robinson from rejects.
« Reply #275 on: March 11, 2018, 09:44:25 PM »
Very Nice  :ThumbsUp:
Craig

Offline Ian j

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Re: A Robinson from rejects.
« Reply #276 on: March 13, 2018, 04:58:47 PM »
Latest progress!
Made a couple of changes:
replaced the Chinese Honda CI piston rings with 2.5mm C/S Viton O rings.
made a better  seal of the ignition tube into the cylinder using a copper washer.
I don't mind admitting to my C*** ups, I had  forgotten  to cut the exhaust port opening in the exhaust gasket ! No wonder I had such good compression :)
Another problem is the gas burner getting blocked ( I remember you mentioning this Graham when we met up at the Anson Museum)
Now using a small pinpoint gas torch to heat the ignition tube I can get it to fire a couple of times in succession ( that's 200 percent better than before)
Just to confirm that the direction of rotation is anticlockwise as you look at the fly wheel side? The reason I ask is some times after firing it try's to go clockwise.
Any way that's it for now.

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #277 on: March 13, 2018, 05:59:14 PM »
Hi Ian.

Great news indeed, and yes anti-clockwise it is.

With the engine trying to go backwards it is suggesting early ignition ( advanced ) try holding the flame a little higher up the tube. This should retard things a little. If you're finding your having to place the heat too far up you might need to make another tube with a fractionally smaller internal diameter. This effectively alters the parameters. In imperial measurements we used to try 1/64" either side of 1/8"

Oh, before I forget, the jets in those burners can usually be unblocked by putting a reverse pressure from the likes of an unregulated CO2/Nitrogen gas bottle or possibly the max pressure from an air line.

Cheers Graham

Offline Ian j

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Re: A Robinson from rejects.
« Reply #278 on: March 13, 2018, 06:09:07 PM »
Thanks for that Graham I will refit the original ignition tube made as the drawings.
Will give the compressed air method to unblock the burner a try.

Offline RayW

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Re: A Robinson from rejects.
« Reply #279 on: March 15, 2018, 05:49:10 PM »
Finished the oiler today and quite pleased with the result. The attached photo shows the original full size one together with the Robinson one in the centre and the Otto one on the right.

Ray
Ray

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #280 on: March 15, 2018, 05:55:47 PM »
Very nice Ray, well done!

How's the " plumbing " coming along?    ;)

Cheers Graham.

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #281 on: March 15, 2018, 06:01:17 PM »
They look good Ray

talking of plumbing what are people doing, will you make an adapter to fit the burners M8x0.75 thread with a more common 1/8" BSP on hte end so it can all be plumbed in with BSP or are you going to do it all in metric or a bit he ME thrown in? Or bodge it and stuff a 5/16x 32ME into the burner ;)

I got the gib key for the flywheel made and fitted last night and no sign of a wobble, also made a greaser for the crank as well as bit for the R&V engine so that can bet test run at the weekend.

Offline Ian j

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Re: A Robinson from rejects.
« Reply #282 on: March 15, 2018, 06:32:19 PM »
My "plumbing"
I made an adapter threaded M8 x .75 to screw into the burner with 1/4" copper tube silver soldered coming out at the bottom, the other end has 1/4" pipe nipple and 1/43/8" x32 ME pipe nut to screw onto the gas valve via another adapter which were 1/4 1/8" BSP. In hind site this gives no vertical positioning adjustment of the burner to advance/retard the ignition.But hay ho I can change it ;D
The inlet to the low pressure valve is via a No.60 drill diam hole.



« Last Edit: March 16, 2018, 08:28:11 AM by Ian j »

Offline RayW

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Re: A Robinson from rejects.
« Reply #283 on: March 15, 2018, 06:58:59 PM »
Hi all.
I have not got as far as the plumbing yet, but will probably opt for an M8 to BSP adaptor. I like Ian's neat setup, but would need to adapt it to allow vertical adjustment of the burner, possibly by incorporating a flexible section of hose into the feed line to the burner.
I have decided to live with the slight flywheel wobble for now, and sort it out once the engine is running, at which point I will strip it down for painting.

Ray
Ray

Offline Ian j

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Re: A Robinson from rejects.
« Reply #284 on: March 20, 2018, 01:05:02 PM »
IT LIVES !!
I made a couple of important discoveries this week end.
I had taken the 2 3/16" dimension on the eccentric strap from the outside circumference rather than the inside so I was nether going to get the exhaust valve timing correct. Also I found out after all these years my gas bottle was fitted with a low pressure regulator, once changed the burner now roars and the ignition tube glows bright red. Also changed the burner feed tube to allow vertical adjustment ( same as on Grahams)
 It appears to be quite tolerant of the exhaust timing but less so on the ignition tube and volume of low pressure gas , in fact I was surprised how little gas is required for ignition.Attached is a link to video (poor quality) The fly wheel doesn't wobble as much as it looks it's more camera shake!

PS. The piece of plastic on the end of the crank shaft is to stop me slashing my thumb again :'(

<a href="http://www.youtube.com/watch?v=Csxf9inFBAE" target="_blank">http://www.youtube.com/watch?v=Csxf9inFBAE</a>
« Last Edit: March 23, 2018, 07:33:21 AM by Ian j »