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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
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

Thread: The Workshop Progress thread 2018
16/06/2018 16:10:54

Hi Thanks for that Jason,

I'm currently doing a CAD drawing for the whole model and from it I could see with a 7/16" stroke the hole centres were closer together. I made it 0.165" so with 2mm holes it would leave just over a 2mm space in between them.

I will look at 0.486 I think there is just enough room to accommodate a slightly longer stroke of around 15/16" to 31/32".

thanks again for your help

geoff

16/06/2018 14:47:40

Hi All

Just completed the pillar and and base for a small Muncaster engine.

Many of you will know that the Muncaster engines were covered by E.T. Westbury in a series of M.E. articles back in 1957. This engine is the simple single oscillator which commenced the series.

Could I ask has anyone made this model to the Westbury/Muncaster sizes and if so what stroke did you use. Neither Westbury or Muncaster specify a stroke for the engine. Using the scale on the Westbury scale drawings it appears the crank has a throw of approximately 7/16" so the stroke I estimate would be 7/8".

Any feedback would be appreciated

Thanks Geoff

20180616_140413.jpg

Thread: Machining a cast wheel what do you grip first?
13/06/2018 19:42:14

Nigel

Tubal cain video on you tube shows how to machine a stuart progress engine flywheel.

Might be of interest to you, it's in part 3

Google making a stuart progress engine and you will find it.

geoff

Thread: small cast iron flywheel
12/06/2018 16:18:47

Hi All

Well I now have the flywheel I was looking for, bought from Stuart models last week.

It is the one used on the progress model and should machine down ok to my upper limit of 60mm.

It's not listed on the Stuart website on the flywheel page but is available to buy separately.

I thought it was bit expensive but having said that I'm glad I bought it last week as Stuart have just put their prices up.

Geoff

20180612_155939.jpg

Thread: Jones .605 Glow engine
10/06/2018 19:42:14

Well done Keith,

.That's an impressive test stand as well

geoff

Thread: bearings
10/06/2018 19:39:35

Mick,

simply bearings have a great range of bearings, may have what you need.

https://simplybearings.co.uk/shop/

geoff

Thread: The Workshop Progress thread 2018
07/06/2018 07:05:32

Yes, agree with Neil. Really nice work, caught my eye this engine, unusual. Well done Jim.

Thread: small cast iron flywheel
02/06/2018 08:12:10

Gentleman, thank you for all your replies on this post, lots of good ideas/advice.

When I finish the model, a simple oscillator I will post a picture.

Thanks again Geoff

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