First Project – Oscillating Engine

[Mark Williams 21Participant @markwilliams21]

Hi Maurice, again thanks for the info it's things I'm sure in subsequent builds I will definitely consider and use however going back to this model I drilled out the cylinder with the correct sized drill for tapping (forget what size off the top of my head), then the hole was tapped followed by considerable hand sanding to remove all machining marks and give me the smoothest finish possible so hopefully during this process I have removed any imperfections which may have caused running issues, but the proof is in the pudding so we will see in a few days when I get it finished lol 👍🏻😎

[Mark Williams 21Participant @markwilliams21]

Update:

Almost there! Just a few bits to do, and some hand finishing as she's a little tight (and yes I mean the model ).

Going away for the weekend so plan to take it and some sandpaper with me and finish it while I'm away (sure the wife will be happy about that!!), then I'll only have the copper tube to solder on and mount the model and she'll be finished.

Edited By Mark Williams 21 on 17/06/2016 08:16:10

[Thor 🇳🇴Participant @thor]

Well done Mark, if the engine is a bit tight, just run it with some oil, it will probably soon bed in. I run mine on compressed air before running them on steam.

Thor

[Mark Williams 21Participant @markwilliams21]

Thanks for the advice, I did think about running it with a little oil however I came to the decision it was too tight so as I had a little more fettling to do anyway I have just stripped it and made a few alterations, just need to clean up the parts a little more and reassemble, all of this I will get done over the weekend.

P.S. While I had it stripped down I milled a circular relief around the trunion pin as suggested by Maurice 👍🏻

Edited By Mark Williams 21 on 17/06/2016 11:01:36

[Ian S CParticipant @iansc]

I seem to remember that my Mamod SE-2 had a recess around the trunion, with a bit of felt in it to hold some oil. You may find that the spring you have is a little heavy, ball point pen springs do ok. Ian S C

[Mark Williams 21Participant @markwilliams21]

The felt seems a good idea, ball point pen springs are out of the equation as the trunion is 6mm 👍🏻

[Mark Williams 21Participant @markwilliams21]

Update:

A little bit closer to getting finished, new knurled nut to replace hex nut on trunion pin, cleaned up a little more and mounted.

I think I only have the inlet/exhaust tubes to solder in and the base to varnish and as long as she runs she will be finished!! Hopefully I will be able to accomplish the above tomorrow.

[Bruce EdneyParticipant @bruceedney59949]

Is it just me or is this missing an exhaust port? I can see how the air/steam can get in but how does it get out?

Bruce

[Bruce EdneyParticipant @bruceedney59949]

Oh wait is that another port on the top???

[Mark Williams 21Participant @markwilliams21]

Posted by Bruce Edney on 20/06/2016 04:49:08:

Oh wait is that another port on the top???

Yes Bruce, the one on top is inlet, the one on the side exhaust.

[Ian S CParticipant @iansc]

Mark, he means the wee one on the port face, there should be two side by side, they line up with the one hole in the cylinder, inlet at one extreme, exhaust at the other. Ian S C

[Mark Williams 21Participant @markwilliams21]

Ah ok I thought he was commenting on the latest pics, I can assure you on the cylinder side there is indeed two holes side by side, one inlet, one exhaust 👍🏻

[Ian S CParticipant @iansc]

Mark, it's usual to have one hole on the cylinder, and two on the fixed block, if it's the other way round where is the exhaust going to go? Ian S C

[Brian JohnParticipant @brianjohn93961]

Would it possible to make an engine like this without a milling machine ? The piston is the big problem.

[Mark Williams 21Participant @markwilliams21]

Posted by Brian John on 21/06/2016 10:19:19:

Would it possible to make an engine like this without a milling machine ? The piston is the big problem.

The plans for this engine are designed so this is made without a mill, I do have a mill so obviously used it.

[Mark Williams 21Participant @markwilliams21]

Posted by Ian S C on 21/06/2016 10:03:12:

Mark, it's usual to have one hole on the cylinder, and two on the fixed block, if it's the other way round where is the exhaust going to go? Ian S C

Hi Ian, it has 2 on the block and one on the cylinder, one of the holes is a blind hole that connects to the vertical hole on the top of the block (inlet), and the other is the one going through the block for the exhaust as per the plan below:

[Ian S CParticipant @iansc]

Sorry Mark, the photo I see must show the side away from the cylinder side, fuss all over. Ian S C

[Mark Williams 21Participant @markwilliams21]

👍🏻

[Brian JohnParticipant @brianjohn93961]

What method would you use to slice off 2.5mm from the cylinder without a mill ?

[Mark Williams 21Participant @markwilliams21]

If you look on the website **LINK** it gives full instructions and shows you how to achieve the mill cut on your lathe

[BazyleParticipant @bazyle]

Slightly easier is to hold it in a 4-jaw but if you only have a 3-jaw it can still be held though purists will shudder but it doesn't need to be centralised in this application so do-able. Put a bridge plate across two of the jaws if the workpiece is a little short relative to the gap.

It's a nice idea having the website pictorial instruction. Anyone else making this might consider making the second port come out the side instead of the back in a similar way to the top one. This will give more 'meat' for attaching a pipe.

Edited By Bazyle on 22/06/2016 16:42:09

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