Portable Engine Model Engineer Article by Tony Webster

[Nicholas FarrParticipant @nicholasfarr14254]

Hi David & Jason, with regards to the slide bar sketch and the question of the 13/16 and 11/16 centres, I believe are being misinterpreted. My understanding of the cross marks these two measurements are referring to are centres of the fixing holes and not of the bars. I do agree that a 3/8 gap makes more sense, in that it makes the 13/16 measurement to be more realistic.

Forgive my rubbish sketch below, but this is how I have interpreted it. At the end where it is shown the 13/16 measurement, there has to be at least 3/32 cut out of the edge of each slide bar to accommodate the loop structure and this would leave 7/32 to accommodate the fixings. If the fixings were to be put in the middle of these 7/32 portions, you would end up with 25/32 centers for the fixings. By adding 1/32 to 25/32 you would arrive at 13/16, which would be a more sensible figure to work to and will give a little more clearance between the loop structure and the fixings.

Regards Nick

[JasonBModerator @jasonb]

Nick thats just about the same as the sketch I did back on page 2 or 3. Great minds think alike

Several of Tony's replys specifically say "bars at 11/16" cts" so its not just teh screw holes nearest the cylinder that are at this spacing. I'm going to show a few of the other parts assembled to the bars and this will show when compared to a photo of the engine that the 1" overall width is the most likely correct, off to work now so will do it tonight.

Edited By JasonB on 15/05/2012 07:38:36

[David Clark 13Participant @davidclark13]

Hi There

I will ask Tony to redo the entire set of drawings.

No point publishing further episodes until it is sorted.

In fact, It will be easier to ask how many people are building it.

If only a few, drop the entire series and offer them a set of the remaining drawings to sort it out themselves.

regards David

 

Edited By David Clark 1 on 15/05/2012 09:22:03

[David Clark 13Participant @davidclark13]

Looking at the next part of the portable, it looks like there are many more errors.
The question is, do I drop the whole series or wait for Tony Webster to correct everything?
It will help me to decide if I know how many people have actually started to build this engine.

Please let me know if you have started this engine ASAP.

regards David

[JasonBModerator @jasonb]

Its a shame if it comes to that, maybe ask in the mag as well just incase there are builders who don't visit the website. I know we did have a set of finished wheels posted by one member but they have gone a bit quiet lately.

I'm happy to look over any drawings in advance if it helps. Or even resurect it using the boiler and wheels that we have at the moment and rehash what you have of Tonys drawings so far if there is any demand. As I have said its has the potential to be a good model and the next step from stationary engines upto traction engines.

J

[David Clark 13Participant @davidclark13]

I have asked in the mag but that is 3 weeks from publication.

Jason, can you email me at

david.clark@myhobbystore.com

Edited By David Clark 1 on 15/05/2012 15:21:41

[JasonBModerator @jasonb]

My e-mail is running slow so I have PM'd you as well.

I won't bother sketching out anymore queries until I know its worth it.

J

[Mike WainwrightParticipant @mikewainwright87512]

David

I have not started to build this model but have been interested in the series and it would be something i would try in the future. If you do scrap the series could you them publish the complete set of drawings so anyone who wants to could try to make the model and check the drawings at the same time.

[David Clark 13Participant @davidclark13]

Hi Mike

Yes, we would not leave readers with part built models.

I would redraw it myself if I had time.

Unfortunately I have to rely on contributors to get it right although I do change the odd error.

On this occasion it was totally wrong.

regards David

[David Paterson 4Participant @davidpaterson4]

I had considered doing a significantly scaled down version of this engine and would appreciate eventuallly getting the full set.

The basis of my consideration was to try and scale to a point where I could use a 2" boiler and so fit within the sub-minature AMSBC code (no boiler certificate required). I have not seen a horisontal valve engine at this scale, and suspect it will be somewhat trick to get it looking right.

[Adam Gregory 1Participant @adamgregory1]

Hi David

I made the wheels last year and have been waiting for the whole project the publish before starting the rest, so if you do decide to drop it a full set of the drawings would be good. May be just have a download off the main site.

Regards Adam

[David Clark 13Participant @davidclark13]

Hi Adam

Send me an email direct.

david.clark@myhobbystore.com

I am making a list.

regards David

[Sub MandrelParticipant @submandrel]

It would be a shame to pull it. I've just got hold of 12" of 2 5/8" copper boiler tube. I'm considering making a small portablethough i woudln't follow tony's design exactly, more likely roughly following one of the ones John Haining featured over the years.

I'm more interested in Tony's construction methods than his measurements.

Neil

[Barry Chamberlain 1Participant @barrychamberlain1]

I recently added an album containing several pictures of Tony's Engine from different angles which some may find useful.

Barry

[BobParticipant @bob17059]

It would be a great shame if this project was pulled from the magazine at this stage. Although I have not started to build one I have been following the articles. It is a model that I would consider seriously in the future.

Bob

[KeithParticipant @keith]

I agree also – it will be a shame if gets pulled.

Keith

[KeithParticipant @keith]

I agree also – it will be a shame if gets pulled.

Keith

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