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Member postings for geoff walker 1

Here is a list of all the postings geoff walker 1 has made in our forums. Click on a thread name to jump to the thread.

Thread: The Workshop Progress thread 2018
30/07/2018 13:11:12

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

Thread: What did you do Today 2018
25/07/2018 07:10:55

Yes definitely looks good Nigel, coming on nicely, keep posting, will be interesting to see the finished item.

Geoff

Thread: Rotary table suggestions for Myford vertical slide
23/07/2018 20:23:16

Hi All,

First of all could I say that I have read through the posts on this thread.

Could I ask does anyone have any experience of the small table offered by RDG. the one with the cream base and a 2 3/4" table.

It looks like it may well serve my purposes, very light milling from the head stock using the vertical slide and the same with my potts attachment set up over the lathe cross slide.

Geoff

Thread: The Workshop Progress thread 2018
22/07/2018 11:04:02

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

21/07/2018 18:33:46

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

20180721_130114.jpg

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

Thread: ME Vertical Boiler & Hand Pump
14/07/2018 12:58:55

Good news for all who are interested in making the M.E. boiler.

M.G. has now completed the articles on the hand pump and will commence the boiler build next month.

Also it will feature every two weeks instead of every month.

I hope M.G. includes a full detailed drawing of the boiler at an early stage so builders can see the whole picture before he starts his constructional series.

Geoff

Thread: Really hope this finds a home....
03/07/2018 13:36:30

Location, location, location.

Probably will find a buyer but the location will deter many, long drive down to the west country.

If it was in the north west, midlands, home counties there would be a lot of interest.

Nice lathe I'd find room for it but too far away, a shame.

Thread: The Workshop Progress thread 2018
30/06/2018 14:29:04

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

29/06/2018 19:55:39

Yes, very nice George.

Do you run on steam or compressed air.

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

24/06/2018 12:28:09

Hi Jim,

To achieve the distinctly non prototypical polished rim on cast iron flywheels, after machining them to size and painting them, I mount them on a mandrel the same diameter as the crankshaft and chuck them up in a 3 jaw chuck on the lathe. Then it's a matter of turning it at a slowish speed (250 - 300 RPM ) and using a file and then progressively finer grades of abrasive paper until a smooth finish is obtained and finally finishing off on a buffing wheel.

Yes this method was great Jim. I've just done a stuart flywheel finishing with 1200 grade wet or dry using light oil as a lubricant.

A final buff and it's come up a treat.

cheers Geoff

Thread: Drummond / Myford M Headstock Bearing
23/06/2018 19:28:47

James,

Go to the drummond web site and SEARCH "m type poor finish cured" in BOTH the files and the photos.

They explain option 2 in detail, "Eugenes bearing dodge".

I've done it and it helps a lot with end float adjustment of the spindle, highly recommended.

Details of the bearing you need is in the drummond file.

Geoff

Thread: The Workshop Progress thread 2018
22/06/2018 09:51:08

It runs very well Jim, a lovely model, excellent detail.

Just looking at the flywheel which I assume is cast iron, super outer rim finish, what's the secret?

What does a stroke of 15mm by 20mm mean?

Geoff

Thread: What did you do Today 2018
21/06/2018 19:15:13

Thanks Brian,

Check your b.s.p. tap and dies before you start.

I didn't and had to buy a couple of carbon steel ones from Tracy Tools.

Geoff

21/06/2018 13:33:02

Finished me Stuart pump today, very pleased. First casting I bought from Stuart, gun metal, lovely stuff a joy to machine. Only problem is that 90% of the work is setting up the casting the actual machining is done in no time. That's the nature of castings though, can't just stick 'em in a chuck. I've created a photo file if anyone is interested. Geoff

20180621_122206.jpg

21/06/2018 13:12:12

Take care Ady, unnecessary movement in old age, we must be careful we don't damage anything, especially the lead screw?

Geoff

Thread: Mogens Kilde's Double Diagonal Engine
20/06/2018 20:12:49

Very nice Chris, love the scale, so much patience needed making detailed parts that size.

Not to mention good eyesight and non arthritic fingers.

I love the parade of parts as well.

Great stuff Geoff

Thread: Boll Aero
19/06/2018 15:20:43

Graham there is another thread in this forum, have you read it, may help you.

Keywords Bollaero glow plug engine

geoff

Thread: simple oscillating engine theory
18/06/2018 21:23:10

But at 1degree either side it will be open so you don't want the piston in the way.

Yes I think you're right there Jason, just checking myself and it's a good 30 degrees before the piston fully clears the port on the down stroke.

Thankfully the solution is simple just shorten the con rod.

thanks again, great simulation, and I'll keep you posted Geoff

18/06/2018 19:06:47

Hi Jason

Geoff, Muncasters drawing (not Westbury's) shows the end of the piston half way across the port when at TDC.

Yes I do have Muncasters book and I can see he has the piston half way across the port hole. The problem I have is that if you take his piston rod length of 1 and 15/16" from the centre of the crank pin to the end of the piston you can't make it fit unless it overlaps the port hole, that being off a 0.486" throw.

JDW also has the piston lapping half way over the port hole.

I may well just shorten the con rod and have it overlapping half way. I was keen to stick as much as possible to the Muncaster sizes but may have to compromise.

thanks for your help Geoff

18/06/2018 18:27:23

Hi All

When the piston in a single acting simple oscillating engine is at tdc is there any guidance I can use as to where the top of the piston should be relative to the inlet/outlet port in the cylinder.

When should the upward travel of the piston stop, just below, over, or just beyond the port hole.

I of course understand that the piston must not block the port hole when the hole is aligned with either the inlet or exhaust on the standard.

Geoff

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