Author Topic: A Robinson from rejects.  (Read 72013 times)

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #195 on: February 12, 2018, 06:19:52 PM »
Good evening all.

As promised....

<a href="https://www.youtube.com/watch?v=xnL8h1em45o" target="_blank">http://www.youtube.com/watch?v=xnL8h1em45o</a>

Cheers Graham.

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #196 on: February 12, 2018, 06:41:32 PM »
Thanks for that Graham.

Offline Chipmaster

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Re: A Robinson from rejects.
« Reply #197 on: February 15, 2018, 01:49:33 PM »
Robinson base minutes after grit blasting treatment. This is the first time I've used a shot blasting firm, they blasted three castings while I waited for about ten minutes and I gave the man £10.
A coat of primer is drying while I add these pictures to this thread.

Robinson X Type by Andy, on Flickr

Robinson X Type by Andy, on Flickr

Robinson X Type by Andy, on Flickr

Robinson X Type by Andy, on Flickr

Plus two dynamo castings
P1070360 by Andy, on Flickr
P1070361 by Andy, on Flickr

Andy

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #198 on: February 15, 2018, 02:53:47 PM »
Now that is what castings should look like none of that iffy coating :LittleDevil:, funny enough I was looking to see how could do it for me locally only last night as some rust is on it's way to me.

Do you have the before pictures?

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #199 on: February 15, 2018, 04:29:56 PM »
Hi Jason.

Cheeky, as ever!  :)

You’ll be able to post some pictures of your own in the near future!

Andy.

That’s just the way they used to leave us however Buckley’s finish had more of a shine because they used Iron shot in their blasters.

Nice to see Vincent’s Manchester dynamo base again.

Cheers Graham.

Offline RayW

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Re: A Robinson from rejects.
« Reply #200 on: February 15, 2018, 07:16:01 PM »
Hi all,

Still making progress and it's really beginning to look like an engine (minus one big round thing!). Assembled all the components loosely today to ensure that everything lined up correctly and turned properly. Just needed to open out the guide hole in the end of the eccentric arm a bit to stop it binding, but otherwise all was good.

On a not quite so successful note, I spent a lot of time making four nice piston rings today, then managed to break all four trying to get them on to the piston. I was trying to open out the rings sufficiently to go over the end of the piston but then remembered, when it was too late, that the best way is to get one end of the ring in the groove first, then progressively work the rest of the ring down. If anyone has any alternative techniques, I would be interested to hear.

Ray

 
Ray

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #201 on: February 15, 2018, 08:16:30 PM »
Hi Ray.

Yes, fitting rings can be a tricky business. I wonder, were they properly annealed ?

I always use the method of opening the ring carefully by placing the edge furthest from the split partially onto the piston edge and then working my way towards the ends. It's not infallible though, I've still broken a few !!

Getting the rings to a bright Orange quickly then allowing a slow cool is my method of annealing them.

Having tried " Viton " in my Gardner I would recommend them over the split cast Iron rings any day !!

Cheers Graham. 

Offline Chipmaster

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Re: A Robinson from rejects.
« Reply #202 on: February 15, 2018, 08:51:45 PM »
Now that is what castings should look like none of that iffy coating :LittleDevil:, funny enough I was looking to see how could do it for me locally only last night as some rust is on it's way to me.

Do you have the before pictures?

Here are the 'before' pictures taken by Graham

Castings 1 small by Andy, on Flickr
Castings 3 small by Andy, on Flickr
Retlas dynamo base before blast cleaning. by Andy, on Flickr

Andy

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #203 on: February 15, 2018, 08:55:16 PM »
That worked well then and saves a lot of elbow grease

Online Jo

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Re: A Robinson from rejects.
« Reply #204 on: February 15, 2018, 09:10:20 PM »
Two sets of Castings  :o I thought it was only me and my supplier who got TWO sets of castings between us, Graham  :stickpoke:

Those castings look so familiar   :noidea:

Jo

P.S. They also have the "slipper view"  ::)
Enjoyment is more important than achievement.

Offline Chipmaster

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Re: A Robinson from rejects.
« Reply #205 on: February 15, 2018, 09:36:23 PM »
Yes you've worked it out Jo, it was the slippers wasn't it :praise2:. I had to copy them from one of your posts as I didn't take any 'before' pics myself   :cheers:. All our castings were in the same state.

I recommend using shot blasters, I would have saved a lot of effort if I had used the shot blasting firm on my earlier engine castings.

Andy

Offline RayW

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Re: A Robinson from rejects.
« Reply #206 on: February 16, 2018, 10:28:17 AM »
Like Graham, I had considered using viton o-rings as piston rings, but not sure how I would do this as the grooves in the piston are not square as would be needed for circular section rings. The grooves are 80 thou wide and 93 thou deep so would require either oval or rectangular section rings, which do not seem to be easily available. I will persist with cast iron rings for now and just make plenty of spares!
Ray

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #207 on: February 16, 2018, 11:21:11 AM »
Hi Ray.

You don’t need to worry about the section of the groove, it’s the width that counts. I have directly substituted round rings into the square grooves on my Gardner piston.

Cheers Graham.

Offline Jasonb

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Re: A Robinson from rejects.
« Reply #208 on: February 16, 2018, 01:26:19 PM »
Postie has been and dropped of a Burner, the "10mm" Sievert is 11mm OD and easier to get hold of, mine came from Hamilton Gas.

For a nominal 3/32" section O ring the best fit will be if the depth can be increased to 0.094" and width upto 0.125"

Offline Alyn Foundry

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Re: A Robinson from rejects.
« Reply #209 on: February 16, 2018, 01:56:32 PM »
Hi Jason.

Your parcel of goodies is on its way, should land on Tuesday.

It’s looking like March will see the appearance of 3 Robinson’s, very nice!

Cheers Graham.

 

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