Strictly.... “ Hot Air “

[Jasonb]

Jo, did you just externally lap the piston down until it fitted the cylinder or did you lap the piston into the cylinder? EG run the two together.

[Jo]

The final finish was done together.

Jo

[Chipmaster]

Here's another one that runs 

<a href="https://www.youtube.com/watch?v=ajBDy7FamYY" target="_blank">http://www.youtube.com/watch?v=ajBDy7FamYY</a>

Andy

[Alyn Foundry]

I was hoping that someone would have come up with some ideas for making the burner using the bits I have for the bigger Robinson by now 

Jo

Good morning Jo.

All the family are " down " with a flu like virus that's been hanging on for weeks, I'm still feeling pretty rough.

I made a very simple gas ring that used the upturned top from the Gardner hot tube chimney top. Using a scrap lump of Steel round bar, a little larger in diameter to that of the chimney top simply bore out a cavity that's smaller than the top then counter bore for 3mm deep at the top's diameter. You can then drill a hole into the side and insert a " Primus " burner for correct mixing.

Andy, ( Chipmaster ) gave me a piece of ceramic removed from a portable gas heater on my last visit but I've yet to try this as an alternative to my 18 hole original design.

Nice paint job Andy!!   

You were making more noise than the engine!!   

Cheers Graham.

[Jasonb]

Jo If you want to keep the height of your burner down then thread the top of a block of metal to take the "gas ring"  and fit the other part which I assume has the jet in it and takes a hose on the opposite end into the side of the block with a suitable extension piece between to bring the plastic valve out to where it won't melt.

Hope you get it made ready for tomorrow

Talking of things melting, given that you had the loctite fail on your crankshaft is it a wise thing to be using loctite on your two part governor fabrication as that is likely to get hotter than the crank should.

J

PS I just got some castings

[Jo]

 

Jo If you want to keep the height of your burner down then thread the top of a block of metal to take the "gas ring"  and fit the other part which I assume has the jet in it and takes a hose on the opposite end into the side of the block with a suitable extension piece between to bring the plastic valve out to where it won't melt.

Yes that was as close to a design I got before I had to go off for an important meeting this afternoon, just got back and will have to see if I can bring both in the morning

The crank failed due to not having an appropriate burner 


Surus tells me he is looking forward to receiving his castings tomorrow (don't forget them or I won't hear the end of it  ) And he is not coming tomorrow as the owner of "his" Stuart Major castings will be there and none of us want to see blood   

Jo

[Jasonb]

Only one set of castings in my package.

[Jo]

Its been hell I didn't come home with any castings yesterday  so I was in trouble


Having completed my penance I have been out in the workshop and machining the platform for the Polly Robinson. This fits nicely in a four jaw chuck and can be turned in the same way as the Alyn Foundry base. Yes this casting (like all of the Polly Castings) has hard spots so a good carbide tipped tool was needed for turning 

The top was skimmed to allow it to be held square and then the bottom could be faced and have the bore cut for the other part of the platform which is integral in Graham's castings.

the water space is covered over with a very nice laser cut part which even has the screw holes marked out for holding the base on. the sides of the casting had a little more draft angle than the plate allowed for so once squared up so that will have to be filled and due to the temperature I will use JB Weld. I am also considering holding the sleeve part of the casting to the main platform with JB Weld to avoid having to drill through from the top 

Jo

[Jasonb]

Its been hell I didn't come home with any castings yesterday  so I was in trouble

The little man would not have wanted them anyway especially once he found the sand in some of the voids

[Jo]

The little man would not have wanted them anyway especially once he found the sand in some of the voids

It was another casting set he was hoping for - My supplier encouraged Alan to bring one of the Stuart Major Beam castings along to the meeting and to put it on my display table 

Jo

[Jo]

A bit more progress on the Polly so it is best I add to the "features" list of the Polly model/drawings:

The two brass castings for the Arms do not match the drawings  This does not actually matter and there is little point trying to change them. And as the Displacer Link is already too wide in the gap of the arm there is no point in thinning down the end of the displacer rod.

The power piston drawing does not show the piston being threaded for the Gudgeon Block (or a nut to attach either)

Both Laser cut arms are ok but the location of the centre pops for the holes for bushes needs pushing over to be more central.

Both mounting plates at the bottom of the crank bearing and the cylinder castings are undersized in one direction but they are dimensions that do not matter.

I am not sure if I really need all of the fixing screws that came with the kit As I normally make my own fastenings I am tempted to make my own again as the ones provided would need cutting down anyway. I am still wondering if I really need to drill holes in the top of the platform to attach the lower piece or if JB Welding it together would be sufficient. I am tempted to give it a go and if nothing else if it fails it will give Jason another reason to  my build 

Jo

P.S. As you can see someone had to check one of his casting sets was still all present and correct  I am hoping to be allowed to fondle them later 

[Alyn Foundry]

Never mind Jason     ing....

Have you managed to repair the " true " half scale engine yet?

I'm sure we're all waiting eagerly for the video.   

Cheers Graham.

[Jo]

I have to make a burner Graham and to do that I need gas jets. Which I forgot to order 

The engine is back together and passed the test on Saturday when he tried poking it.

Jo

P.S Did you get the PM?

[Jasonb]

Don't be silly Graham she can't repair the 1/2 scale engine until the RLE has been repaired.

I suppose the JB Weld will be fine after all its only going to sit in a dark corner almost finished with the rest

Why can't you unscrew the jet from that old gas ring that you had a t the weekend,

[Jo]

Why can't you unscrew the jet from that old gas ring that you had a t the weekend,

Size matters    I am waiting for Jerry at Clevendon Steam https://www.clevedonsteam.co.uk/products.html to come back to me on the delivery...

Jo