First Project – Oscillating Engine

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First Project – Oscillating Engine

This topic has 45 replies, 12 voices, and was last updated 22 June 2016 at 16:37 by Bazyle.

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14 June 2016 at 15:43 #31134
Mark Williams 21
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@markwilliams21
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14 June 2016 at 15:43 #242796
Mark Williams 21
Participant
@markwilliams21
Hi All,

As the title says I have finally started my very first model engineering project.

I bought a Myford ML7 lathe and a Sieg mill around six months ago but as I hadn't finished getting my workshop ready I was unable to use them and get anything started, anyway the workshop is all but complete and over the last few weeks I have been busy getting everything I need for my first project.

While waiting to get started I trawled the internet and found what I believed to be the simplest Oscillating Engine I could find check out http://www.steves-workshop.co.uk if anyone is looking for an easy first build. I then got myself the materials and final tools I needed to start.

Below are pics of my progress, any helpful hints and tips off the experienced builders out there would be most appreciated.

The picture above shows the cylinder with its cap sat in place (top left), I still need to drill these to fix the cap on, next is the crank bushing (top right), again needs drilling for fixing to the frame and last is the frame also requiring drilling to take the bushing however all of the other holes are drilled including steam inlet hole on the reverse side which enters on the top, also fixing holes have been drilled and threaded on the bottom ready for mounting.

Not the best picture I know and for some reason it turned 90deg between taking it with my phone and uploading it to here. This shows my base plate just sprayed with black enamel paint and drying in sun.

The parts shown aren't absolutely perfect but for my first project and with little to no engineering/machining experience I'm pretty happy and I've learned loads already.

More progress pics to follow!

Mark
14 June 2016 at 16:23 #242804
Thor 🇳🇴
Participant
@thor
Hi Mark,

Your oscillator is coming along nicely, looking forward to see your progress. I have made a few oscillators myself, both single-acting and double-acting, great fun.

Thor
14 June 2016 at 16:26 #242805
Mark Williams 21
Participant
@markwilliams21
Posted by Thor on 14/06/2016 16:23:54:

Hi Mark,

Your oscillator is coming along nicely, looking forward to see your progress. I have made a few oscillators myself, both single-acting and double-acting, great fun.

Thor

Thanks Thor
14 June 2016 at 17:15 #242808
Neil Wyatt
Moderator
@neilwyatt
Hello Mark,

Looks like you are making good progress!

Neil
14 June 2016 at 17:53 #242814
Peter Krogh
Participant
@peterkrogh76576
Oscillators are fun and satisfying to build. Looking good so far!

Pete
14 June 2016 at 17:58 #242816
Mark Williams 21
Participant
@markwilliams21
Thanks Gents
14 June 2016 at 18:29 #242818
Bazyle
Participant
@bazyle
As you mentioned "bushing" and "sun" I figured you weren't from the UK, but seeing another post about purchasing tools from an UK supplier now I'm confused.
14 June 2016 at 18:42 #242821
Mark Williams 21
Participant
@markwilliams21
I beg your pardon, bearing and cloud with more than occasional rain 😛
15 June 2016 at 11:53 #242875
Mark Williams 21
Participant
@markwilliams21
UPDATE:

Piston cap and main bearing drilled, threaded and bolted to the necessary parts,and assembled what I have up to now

From a slightly different angle, I have also opened up the inlet/exhaust holes slightly ready to silver solder copper tube in.

I think its looking ok, certainly coming together!!
15 June 2016 at 11:57 #242877
Mark Williams 21
Participant
@markwilliams21
P.S. Used M1.6 threaded rod and nuts which was fun…..not 😎
15 June 2016 at 12:17 #242880
mechman48
Participant
@mechman48
Coming along nicely there Mark.

George.
15 June 2016 at 14:18 #242892
Thor 🇳🇴
Participant
@thor
Hi Mark,

You are making good progress on the engine, nice photos.

Thor
15 June 2016 at 15:02 #242901
Neil Wyatt
Moderator
@neilwyatt
15 June 2016 at 15:51 #242907
Mark Williams 21
Participant
@markwilliams21
Thanks Gents, am going to see how much I can get done tonight, would hope for the piston assembly and maybe the flywheel but we'll see 👍🏻
15 June 2016 at 18:57 #242917
Maurice Cox 1
Participant
@mauricecox1
Hi Mark, nice work! There is one point that I would like to raise. It is helpful to relieve the area round the trunion pin, as, when the two surfaces wear as the engine runs, the centre area will wear more slowly than that which is moving faster and further. Relieving it will allow the faces to remain in contact more easily. On the Stuart Turner oscillator, they mill a slot across the port face on the standard, about 5/32" wide. An old Bowman that I had, had a 3/8" counter bore round the trunion pin hole. There is something similar on the remains of another old engine I have, only it's 1/2" diameter. I'm sure your engine will run perfectly without this relief, but it will remain, well not exactly leak proof, but in good working order for longer if you do it. Keep up the good work.

Regards Maurice
15 June 2016 at 19:02 #242918
Mark Williams 21
Participant
@markwilliams21
Hi Maurice, thanks for the advice however being a complete beginner I am unsure of what you mean, any more pointers or pics you could give to aid my understanding as any modifications I can make to add longevity to my engine would definitely be considered

thanks

Mark
15 June 2016 at 21:35 #242930
Maurice Cox 1
Participant
@mauricecox1
Hi Mark; yes, certainly. I will post a couple of pictures tomorrow. The idea is that the two flat faces only touch in the area of the ports, and are able to bed together without the unworn central area stopping the process. Can't take the pics before that; sorry. Will do A.S.A.P.

Maurice
15 June 2016 at 22:25 #242934
Anonymous
Posted by Mark Williams 21 on 15/06/2016 11:53:50:

I think its looking ok, certainly coming together!!

Looks a darn sight better than ok to me. I'd be happy if my stuff looked like that.

Andrew
16 June 2016 at 11:00 #242984
paul asselin 1
Participant
@paulasselin1
looks cool, keep it up
16 June 2016 at 11:08 #242985
Mark Williams 21
Participant
@markwilliams21
thanks guys!

UPDATE:

Piston/conrod assembly machined just requires hole for fitting onto crank

Piston in cylinder, I hand finished with 400 grit paper to get the best fit I could

I also learned a valuable lesson about the sharpness needed on your lathe tools
16 June 2016 at 17:43 #243024
Maurice Cox 1
Participant
@mauricecox1
Hi Mark, here are the pictures of port faces that I promised. Sorry for the delay. The Bowman I no longer have, but here are An old Stuart ( I have five of various ages, all have the slot); The remains of a horizontal engine of uncertain make, with a circular relief round the trunion pin, and finally a German engine from before WW1. The port face is actually a brass pressing. It has the slot pressed in. In the well known book by K.N.Harris on making stationary engines, chapter 2 is devoted to oscillating engines. The drawings he includes show both circular and the slot type of relief, although curiously he does not mention it in the text. Personally , I prefer to put a slot across the face where the trunion pin is. It is easier than counter-boring, and I believe it is more effective. Keep up the good work on your engine; I look forward to seeing it finished.

Maurice
16 June 2016 at 17:44 #243026
Maurice Cox 1
Participant
@mauricecox1
Sorry the text is mixed in with the pics, I always manage that! Sorry!

Maurice
16 June 2016 at 18:06 #243030
Mark Williams 21
Participant
@markwilliams21
Thanks for the pics and information Maurice I see what you mean now, I may have a play on my milling machine later 😉 I'll post pics if I get the bottle lol
16 June 2016 at 19:07 #243041
Maurice Cox 1
Participant
@mauricecox1
Hi Mark, just been thinking about your trunion pin. How exactly did you go about tapping the hole in the cylinder? When tapping almost anything, I drill the tapping size hole, then follow with a clearing size drill to the depth of one, to one and a half threads. Then I tap it. This avoids the little "volcano" that appears as the tap goes in; particularly with ductile metals. If you flatten a scrap piece of brass, tap a hole in it, cover the flat surface with marking out blue, then rub it it on a piece of emery paper, you will be surprised how far the raised are round the tapped hole can go. This could stop your engine from working well when it is finished. Putting a clearing drill in after tapping seldom works, as the lump will be of a greater diameter than the clear drill, and it will not look good as the thread will make the drill start off centre. Hope this might be of help.

Maurice
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