By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale July 23rd

The Workshop Progress Thread 2019

All Topics | Latest Posts

Search for:  in Thread Title in  
JasonB19/08/2019 07:25:15
avatar
Moderator
15988 forum posts
1680 photos
1 articles

Thank's Ron, I think it was that video that first got me thinking of making the engine so I got the 1938 Practical Mechanics Shop notes that had both of the two part article in them. One shows the patterns to make your own castings and the other the construction.

I have scaled it down from 1 1/4" bore to 24mm and altered just about every part in some way but still kept to the basic layout and overall look. As you noted the simple rockers and bent wire pushrods are a bit basic so I have some shapely rockers ( see the KX£ adventure thread) with screw adjusters and the tappets ride in bronze bearings. I will deviate a bit on the carb which is just a plain venturi type on the original by adding a throttle and doing something a bit nicer than the metal pot seen in the video for the fuel tank. As the engine is just for show being able to blip the throttle will be more enjoyable than having it just running flat out and also save it getting too hot while stationary.

Although several illustrations show the engine in a boat hull this one is an interesting use for it and if Michael G. is looking in he will approve of the tool being used. Also shows the basic rocker and rod design. midget rockers.jpg

 

Edited By JasonB on 19/08/2019 07:35:56

Ron Laden19/08/2019 07:57:27
avatar
1287 forum posts
219 photos

Good stuff Jason, those adjustable rockers look far better than the plain flat type. I was going to ask about the carb, when watching the video I was waiting for the throttle to be blipped but as you say it is just runs at a fixed speed. A carb with a throttle will be a good upgrade I think.

Michael Gilligan19/08/2019 08:54:37
avatar
13780 forum posts
599 photos
Posted by JasonB on 19/08/2019 07:25:15:

Although several illustrations show the engine in a boat hull this one is an interesting use for it and if Michael G. is looking in he will approve of the tool being used.

midget rockers.jpg

.

What an amazing illustration that is !!

MichaelG.

Ron Laden19/08/2019 10:46:45
avatar
1287 forum posts
219 photos
Posted by JasonB on 19/08/2019 07:25:15:

Thank's Ron, I think it was that video that first got me thinking of making the engine so I got the 1938 Practical Mechanics Shop notes that had both of the two part article in them. One shows the patterns to make your own castings and the other the construction.

I have scaled it down from 1 1/4" bore to 24mm and altered just about every part in some way but still kept to the basic layout and overall look. As you noted the simple rockers and bent wire pushrods are a bit basic so I have some shapely rockers ( see the KX£ adventure thread) with screw adjusters and the tappets ride in bronze bearings. I will deviate a bit on the carb which is just a plain venturi type on the original by adding a throttle and doing something a bit nicer than the metal pot seen in the video for the fuel tank. As the engine is just for show being able to blip the throttle will be more enjoyable than having it just running flat out and also save it getting too hot while stationary.

Jason, would I be correct in thinking that the bottom of the rocker adjusters are cup shaped and the push rods will be ball ended to fit inside..?

JasonB19/08/2019 12:20:01
avatar
Moderator
15988 forum posts
1680 photos
1 articles

That's Right Ron, some models tend to use upturned cap heads screws but I put a fine straight knurl on some 4mm steel and then reduced turned the end down for a M2.5 thread before using a 3mm ball mm nose cutter to make the recess. I'll be making all my own period fixings, the cap heads are just easy during construction.

The reason these engines did not have a throttle was they often went into tether boats where you had no control of the engine just dropped the boat into the water running and timed it to see how fast it could complete a set number of loops, at this sort of period they were getting around 50mph out of the top ones.

Michael, the whole of the old magazines make interesting reading as they cover many subject and the adverts are as interesting or more so than the articles. Page 626 of the 1936 edition has the article about making the castings.

The fuel tank turned up today along with some spares so that jamjar Maytag engine could be a possibility. I'm sure the postie must think I'm getting into jam making as I also bought some 8oz Mason jars for another engines vapour tank.blush

dsc03738.jpg

Jim Nic28/08/2019 14:04:00
avatar
203 forum posts
107 photos

At long last I have completed Stew Hart’s Overcrank engine. I knew when I started that it was a step up from anything I’d done before but thanks to Stew’s excellent drawings (which I believe were not originally drawn with publication in mind) and a bit of thought and common model engineering sense the result is shown below.

overcrank finished 1.jpg

overcrank finished 2.jpg

overcrank finished 3.jpg

overcrank finished 4.jpg

And a vid:

It has taken the best part of a year but I’m pleased with it. Thanks to Stew for the drawings.

Jim

JasonB28/08/2019 16:00:06
avatar
Moderator
15988 forum posts
1680 photos
1 articles

That has turned out very well, nice slow runner too.

mechman4828/08/2019 20:43:18
avatar
2432 forum posts
372 photos

Another fine model Jim, nice runner too .

George.

Mogens Kilde28/08/2019 20:50:16
60 forum posts
25 photos

A very nice engine - absolutely great job

Thank you for sharing !

Neil Wyatt29/08/2019 10:58:52
avatar
Moderator
16415 forum posts
685 photos
74 articles

Lovely model Jim, congrats to you and well done to Stew for the original design!

Neil

geoff walker 129/08/2019 11:54:51
310 forum posts
132 photos

Hi Jim

Lovely job mate, there's a lot going on with that engine, and only a year to make. I wouldn't be halfway there

Well done

Geoff

Jim Nic30/08/2019 14:42:41
avatar
203 forum posts
107 photos

Thanks for the kind comments gents.

A little bit of a mod to do on my Grasshopper Beam engine pipework then its on to the next project - a Muncaster designed Double Acting Oscillator using the cylinder casting kindly given to me by Geoff Walker. This engine will present me with its own challenges as I am not good with castings having only used them on a Stuart Models 10V and my Grasshopper Beam (which did not turn out well with several of the castings being discarded after my attempts on them!). I have the barstock materials on order, the cylinder casting and some drawings so I'm committed now.

Jim

John Hinkley31/08/2019 11:43:09
avatar
741 forum posts
248 photos

Not really workshop progress, but progress nevertheless, albeit with the continuing saga of my gearbox design. I had all but completed the internals, when I found that I'd messed up the gearchange mechanism, such that I'd ended up with the 4th and 5th gear gate in the middle! After a bit of head-scratching (and not a little profanity), I got it sorted with a bit of a re-design of the two offending selector forks and their associated rods. The "finished" design is illustrated below :

Gearbox internals

Anticipating starting to cut metal soon, I've emailed Abbey Castings to ascertain whether they can cast the selector forks in bronze for me, in a "raw" state, ready for me to machine to finished size, but have yet to receive a reply. Perhaps they are on holiday? I'll try ringing on Monday.

John

Mark Gould 109/09/2019 16:40:54
124 forum posts
86 photos

John,

I am amazed to think you are designing a gearbox, i only vaguely undertand them! looking forward to seeing the progress, do you plan to take any phtotos to share with us?

Mark

John Hinkley09/09/2019 17:15:06
avatar
741 forum posts
248 photos

Mark Gould 1,

To be fair, I have leaned very heavily on the expertise of Mr. Hewland; the design being based on the 5-speed version of the FT200 gearbox that they produce. I have chosen my own gear ratios to suit the scale of the model and it is intended to be a demonstration of the principles of gearbox operation, not necessarily to be fitted to an engine. At least, not in the immediate future - but never say never. I'll take a number of photos of the progress if I consider them to be significant to the build and put them with the others in the album, along with the brief notes which accompany them. From time to time I may well stick a couple in this thread, too.

If I can get into 3D printing, I will try to design a casing to hang it all in, but for the moment my ambition is to support the gubbins on perspex or similar plates so that the workings can be observed. We'll see - literally!

For some idea of size, the input and output shafts are 190mm long and the gears are 1.5MOD, the largest being a shade over 60mm in diameter.

Thanks for your interest.

John

duncan webster12/09/2019 15:14:58
avatar
2197 forum posts
32 photos

Today I finished the latest batch of signals, and I'm hoping it's the last. This makes 13 I've made, but it does add to the enjoyment of driving little puffers, and helps to avoid running up the back of the train in front when he has run out of chuff just round a blind bend.

Next step AWS to tell the drivers to stop messing with the fire and look at the signals!

img_3673 (small).jpg

img_3683 (small).jpg

Edited By duncan webster on 12/09/2019 15:15:27

Nick Clarke 313/09/2019 12:49:17
avatar
358 forum posts
9 photos

Something to physically attract their attention instantly perhaps? smiley

images.jpg

(From Akira Kurosawa's film 'Throne of Blood' - Macbeth retold with samurai)

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
TRANSWAVE Converters
Eccentric July 5 2018
Advertise With Us
Warco
Eccentric Engineering
ChesterUK
Ausee.com.au
Meridienne Sept 2019
emcomachinetools
Allendale Electronics
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest