Author Topic: Twin Oscillators  (Read 5674 times)

Offline b.lindsey

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Re: Twin Oscillators
« Reply #60 on: May 26, 2019, 03:09:30 PM »
Coming along well Jo. That is quite an interesting casting too.

Bill

Offline Jo

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Re: Twin Oscillators
« Reply #61 on: May 26, 2019, 03:32:44 PM »
Thanks Bill,

Yes Stuarts thought that base casting out very well to get all the steam pipes hidden away  :)


Before I headed in I decided I really should finish off the cylinders: On the flat face we need two holes drilled at an angle and the central pivot drilled and tapped 5BA. The face was rubbed on a piece of carbide paper over the surface plate to get it smooth, then the three hole centres marked out and centre popped. The pivot hole was easy to drill and tap but I was a bit concerned that the pressure of the drill may deform the bore so was careful not to go too far in.

The two port holes were drilled using the vice in a vice trick. But as it needed to be drilled at an angle and it is only drilled with a  rather flexible 1.6mm drill it was necessary to use a centre drill to start the drill hole before drilling through.

At this point I decided to check the bore with a piece of the appropriate sized silver steel to find that yes drilling the pivot hole had indeed caused a high point on the bore   :facepalm2: This was removed through honing.

I was a little worried when I saw the bit of Stainless supplied for the piston rod would be hard as nails as it had been cut off using an angle grinder  :paranoia: But when I tried turning it found it was just Stuarts using the standard Foundry parting off tool rather than a saw.

I would have liked to finish piston rod assemblies today but time is getting on and I am feeling tired so it is time to close up the workshop and go and think about dinner before its race time  :whoohoo:  :wine1:  :wine1:  :-X

Jo
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Offline Jasonb

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Re: Twin Oscillators
« Reply #62 on: May 26, 2019, 04:38:55 PM »
............... before its race time  :whoohoo:  :wine1:  :wine1:  :-X

Jo

Did not think you were a fan of Indy racing :LittleDevil:

The other race has finished and was won by  :-X :-X :-X :-X :-X :-X

Offline Jo

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Re: Twin Oscillators
« Reply #63 on: May 26, 2019, 05:16:11 PM »

The other race has finished and was won by  :-X :-X :-X :-X :-X :-X


This is what comes if you have no self control   :disappointed:. You have to pay an arm and three legs to Sky every month to be able to watch the race live. Where as others of us wait a few hours (hoping that no one tells them the result before they can watch it   :stickpoke: ) have invested their money on early retirement   ::)

Jo
Usus est optimum magister

Offline Jo

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Re: Twin Oscillators
« Reply #64 on: May 28, 2019, 04:44:31 PM »
The pistons were roughed out on the 12.7mm bar before drilling and tapping and turning to fit the bore of the cylinder.

The other ends of the rods has some odd looking big ends. these are taken out of two pieces of square bronze of 6.2mm sq  :headscratch: Having faced these and marked the centre of the rods there were set up in the four jaw chuck to have the end turned and drilled/tapped for the rod. It was necessary to drill to 4.5mm depth (which was near the running surface  :o ) to be able to get my plug tap to cut sufficient tread for the rod to fit tight. [Sorry forgot to take a pic  :Doh:)

Then the pieces of bronze were taken over and mounted in a machine vice to have the bearing surface drilled and to have the 2.1mm taken off the side next to the rod thread. The end could then be turned off and cleaned up with a needle file.

There are not many bits to go, I might have to start negotiating the next castings set, maybe it is time to deploy the Snickers Ice cream to see what casting sets might be forthcoming :thinking:

Jo
Usus est optimum magister

Offline b.lindsey

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Re: Twin Oscillators
« Reply #65 on: May 28, 2019, 06:07:50 PM »
Those turned out well Jo. Hmmmmm...Snickers ice cream...that should do the trick and loosen Surus' grip some  :D

Bill

Offline crueby

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Re: Twin Oscillators
« Reply #66 on: May 28, 2019, 06:20:33 PM »
Those turned out well Jo. Hmmmmm...Snickers ice cream...that should do the trick and loosen Surus' grip some  :D

Bill
Trail of chocolate covered peanuts into the other room as a distraction?

Offline Jo

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Re: Twin Oscillators
« Reply #67 on: May 28, 2019, 07:50:00 PM »
I have his attention  :mischief:

Jo
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Offline Jo

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Re: Twin Oscillators
« Reply #68 on: May 29, 2019, 05:07:46 PM »
Initial assembly of the engine showed that the big ends on the piston rod need to be modified to enable the two rods to move next to each other.

As they were taken off I realised that I had not yet fitted the blued steel... or rather blued Aluminium  :headscratch: At least being Ali means it should be easier to bend. I checked the length of the ali and found it has sufficient length to go round the cylinders (the length on the drawings is rather tight)

It was a short day in the workshop today as the nice man from Waitrose was bringing us another 2 boxes of Snickers Choc Ices and if I hoped to see then I had to be in the house when they arrived  ::) All I can say is a new set of castings is looking likely, the question is how many of the new ice creams it will take to acquire them.

Hopefully this engine waill be finished tomorrow  :)

Jo
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Offline Jasonb

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Re: Twin Oscillators
« Reply #69 on: May 29, 2019, 05:22:16 PM »
Almost there.

Looking back at the drawing I wonder if the 9/32" dimension should have been from the rod end of the big end as that would have given the bit of clearance needed?

J

PS I'll stick to magnums :LickLips:

Offline Ye-Ole Steam Dude

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Re: Twin Oscillators
« Reply #70 on: May 29, 2019, 07:41:17 PM »
Hello Jo,

You might have already stated and I am sorry if I missed it, but what is the angle between the two cylinders. Looks to be greater than 90 degrees.

Have a great day,
Thomas

Offline Jo

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Re: Twin Oscillators
« Reply #71 on: May 29, 2019, 08:16:20 PM »
Hi Thomas,

Both engines have 90 degrees between the cylinders.

PS I'll stick to magnums :LickLips:

There are none of those left  :disappointed:

Jo
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Offline Ye-Ole Steam Dude

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Re: Twin Oscillators
« Reply #72 on: May 29, 2019, 08:30:36 PM »
Hi Thomas,

Both engines have 90 degrees between the cylinders.

PS I'll stick to magnums :LickLips:

There are none of those left  :disappointed:

Hello Jo,

I guess it is the angle of the photo, thanks for the info.

Have a great day,
Thomas

Jo

Offline Old Bill

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Re: Twin Oscillators
« Reply #73 on: May 29, 2019, 09:35:37 PM »
Coming on nicely, Jo. You have just reminded me that I made one whilst I was at school and this is it! It could do with a good clean though, rather than the cursory dusting it has just had. This was my solution to the plumbing challenge. Many ways of skinning a cat!





What's next?

Steve   :)

Offline b.lindsey

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Re: Twin Oscillators
« Reply #74 on: May 29, 2019, 10:44:27 PM »
Great news Jo. So what has Surus' been letting you look at or fondle for a next project??

Bill