The Workshop Progress thread 2018

[geoff walker 1Participant @geoffwalker1]

Could I ask a general question here.

A lot of "older" designs have a crank arm which is very simple and not balanced with a web the opposite side to the crank pin.

Why is that, do some engines just not need it?

Geoff

I think that model engines at this scale running at representative speeds don't need balancing weights on the crank. However, for appearance sake sometimes they are included.

Thanks for your reply Jim. From what I have observed I get the impression that the longer stroke engines with a larger flywheel and a slower speed are less in need of a balanced crank than a high speed short stroke engine.

The Muncaster I am currently making (slowly) has an unbalanced crank, large flywheel and a long stroke. I'll try it and see how it runs.

Thanks again Geoff

[mechman48Participant @mechman48]

So, I have been keeping a build record with dates & hrs spent in the man cave on this build & I've totted up the number of hrs on this, taking into account rehashes & redo's, setting up equip't etc. came to … 228 hrs, spread over weeks from June 2017 when I started it off. It's amazing how much time is spent on projects innit!. I've also costed it out in man hours, at a very conservative rate of £10 ph… £2280…. expensive toy if I were to buy it, but it's the fun in building something… I keep telling myself ! ​… plus it keeps the old grey matter's neurons flashing about. Ho hum what t'do next .. ..

​George.

[Neil WyattModerator @neilwyatt]

While it's interesting to put a price on time spent on making something like your model, I look at it the other way around.

Hobbies, pastimes and leisure are among the things that make life worth living, along with family, friends and perhaps community action etc.

We don't need to price them, because they are priceless; they are our own time and whatever we put in in terms of time and money doesn't really matter, because the quality of our lives and what we choose to do with them is what really measures our riches and fills the hours with time well spent.

[Mark RandParticipant @markrand96270]

I've got a bit of woodspoiling to do in making a housing for the dust extractor and a secondary filter, so I converted the bench back from welding mode to woodspoiling mode. This involves unbolting and lifting off the 5' by 20" by 8mm plate that overhangs the front of the bench (so I can sit on a chair with my legs tucked under while TIG welding), cleaning everything up and then bolting the chipboard+formica top back on the bench.

After that, for no sensible reason, I decided that all of my woodspoiling chisels needed resharpening. To be fair, some of them have been in the family for more than 50 years and have been used as wood splitting mauls as much as joinery tools. Also, neither Father or I were all that good at sharpening chisels evenly. As a result of which, some of them need a couple of mm taking off the length to get to a flat relief…

I have cheated and set up the universal vice on the surface grinder and am starting off by putting a 25° primary angle on all of them. After that, they'll get the secondary relief, if any, added at an appropriate angle for their intended use. Thus far I've done four, with fourteen more to do, but most of the effort was with setting up and doing the first one.

I think I might also have a go at the cold chisels and brick bolsters while I'm at it.

It's a bit slow and fiddly as a grinder job, but an order of magnitude faster than a Norton stone.

[mechman48Participant @mechman48]

Neil, completely at one with your comments; 'twas just an exercise out of curiosity. It certainly was a pleasure albeit at times annoying & frustrating, mainly down to my faults, to build it. Certainly didn't / won't stop me enjoying it all.

George.

[Jim NicParticipant @jimnic]

After completing my version of Ray Hasbrouck’s No 3 Rocking Valve engine I was at a bit of a loose end because that engine seemed to finish all of a sudden and I hadn’t seriously considered “What next.” I gave a lot of thought to Julius de Waal's drawings of the Monitor engine from Model Engine Maker site. I have never been keen on his drawing layouts, I find them difficult to follow (probably due to my advancing years and retreating brain power), but downloaded them and gave them a good looking at while I spent some time cleaning my workshop and attending to machine maimtenance. I had got to the point of deciding to give it a go when I happened upon a ME forum query regarding Stew Hart’s Over Crank engine. I remembered following Stew’s build 7 or so years ago and thinking it was well beyond me, but that was then and this is now so I messaged Stew to ask for a copy of the drawings and he very kindly sent them to me.

The result:

Somewhere amongst this pile is an Overcrank Engine (I hope). It’s a fairly complicated twin cylinder beast so should keep me occupied for a while. I’ll do my best to do the design justice and may post random thoughts on my progress when anything significant occurs.

Jim

[geoff walker 1Participant @geoffwalker1]

Looks a good choice to me Jim, keep us posted.

Here is my recently completed mini muncaster oscillator. Really enjoyed this build.

Here is a picture. The sizes are much the same as the principle Muncaster/ Westbury sizes

Video on you tube if you want to see it working. Sorry I'm thick when it comes to loading you tube videos,

perhaps Jason will oblige. Geoff

Edited By JasonB on 21/07/2018 19:17:33

[JasonBModerator @jasonb]

Looks good and runs well Geoff.

Edited By JasonB on 21/07/2018 19:17:57

[Jim NicParticipant @jimnic]

That's a good looking "wobbler" Geoff, good work and a good runner too. I like the upside down look like which is a long way from the run of the mill oscillator design that I did for my first engine. Well done.

Jim

[geoff walker 1Participant @geoffwalker1]

Hi Jim, Jason,

Thanks for your comments.

I have prepared a detailed CAD/PDF drawing of the engine to my sizes. Much the same as the Muncaster/Westbury I've just "beefed it up a little",

Anyone who would like a copy P.M. me and I'll get one to you.

Geoff

[JasonBModerator @jasonb]

The Robinson X-Type has been sitting in the workshop for the last couple of weeks in it's new shiny paint waiting for some weather that was more conducive to starting engines.

Despite what one or two may say we all know that an engine is not really finished until it has been painted and runs. So with a drop in the temperature and the prospect of more castings arriving soon it was out to the workshop early for some flywheel flicking.

I'd like to say thanks to Graham Corey for making this engine possible by providing some of his rejects and the wisdom he has shared with those of us building the X-type on MEM Forum.

 

Edited By JasonB on 28/07/2018 19:57:20

[Jim NicParticipant @jimnic]

As always Jason a beautiful looking model and a good runner with an interesting "beat" to the rhythm.

The standard of your models gives me something to aim at even if I may never match what you produce.

Jim

[Brian HParticipant @brianh50089]

The Robinson engine looks and sounds good Jason. Can I just ask about the oval nameplate? was it home made or bought and if bought, where from?

Brian

[JasonBModerator @jasonb]

The name plate is a photo etched one that came with the castings.

[Brian HParticipant @brianh50089]

Many thanks Jason, that looks a high quality photo etch.

Brian

[Ian HewsonParticipant @ianhewson99641]

Nice engine Jason, don’t know how you find time to fit all you do in to a day!

Did you have any oil in the cups when you ran it?

[JasonBModerator @jasonb]

Thanks Ian. I just used a small dropper bottle to put a drop or two in the main bearing cups and onto the exposed piston rather than fill the drip lubricator. I was running it dry, the base is usually filled with water for cooling so kept runs down to about 2mins before allowing to cool.

[mechman48Participant @mechman48]

Geoff; super little oscillator, looks nicely balanced too, not trying to vibrate off the table.



​Jason B; superb job, lovely running & a lovely paint job. Well done both of you,

George.

[geoff walker 1Participant @geoffwalker1]

Another sumptuous example of craftsmanship Jason, well done

Like many others I envy not just your talent but the efficiency with which you turn out these lovely models.

Geoff

[Mark RandParticipant @markrand96270]

Just out of curiosity Jason, about how many hours a week do you spend int the shed?

[Jim NicParticipant @jimnic]

About half of 'em and the other half is spent responding to queries on most of the modelling forums. (For which I for one have cause to be grateful.)

Jim

[JasonBModerator @jasonb]

In the winter I can usually manage a couple of evenings of about 2.5hrs each and a couple of half days at the weekend so maybe 15hrs total a week. Less in the summer once the grass and my Bonsai start growing.

I did notice in the latest ME that there was a 4" Burrell built in 5 months (get your finger out Andrew! )

[JasonBModerator @jasonb]

With the workshop back down to a more comfortable temperature I was able to make the fitted pins that the Robinson linkages pivot on, quite happy with the way it turns over so far.

I then did some of the furnace base, I'm going for the look of the coal fired version which will also have a small chimney rather than the more often modeled three legged base,

Short vid of the motion.

[mechman48Participant @mechman48]

Have started on my 'Boxer Oscillator, marked off the frame, roughly cut out & drilled for crank & ports…

​Looks rough I know but we all start at this point don't we…

George.

[Jim NicParticipant @jimnic]

Looks great George, particularly like the paint job. (You have at least made a start)

Jim

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