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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: M Type Apron Direction
04/02/2019 11:33:53

Hi Ian,

Picture below of the mew issue 234 conversion.

If you have a go, don't buy the gears from Muffets like I did, very expensive. Use either Boxford or Myford change wheels and modify them, i.e. change the hole size by bushing the existing hole. Lot cheaper way.

I also made a pattern and had a complete new apron cast for the myford, lot of work but neat with the gears enclosed inside.

20140123_112617.jpgimg_2873.jpgimg_2891.jpg

Geoff

Thread: Jason's Firefly .46 Build
24/01/2019 22:37:46

Hi Ian,

Good luck with the rest of your build.

I made two pistons for my firefly. The first one I made a poor job of lapping it into the liner. The engine ran but lacked power and when used on a model aeroplane it just had enough power to "limp" into the air.

With the second piston I made sure it had a good square leading edge and I only lapped it up to TDC. The first piston I lapped right up to the end of the liner which was a I feel the mistake I made.

If you do some calculations you will see that TDC is 0.8 mm below the underside of the cylinder head boss. I lapped up to that point and it made a big difference to the compression and the power output.

Just my thoughts Ian, hope they are of interest

Geoff

Thread: Small Milling/Drilling Spindle (again)
08/01/2019 18:58:25

Steve

As you are very limited on space ... I would make the body from good cast iron, or bronze, and turn the bearing surfaces directly into it. Preferably a double cone each end [as per the classic watchmaker's lathe headstock bearing]; but realistically, I'm sure a single cone each end would do nicely.

Plain cone bearings tend to 'bed in' rather than wearing out.

MichaelG.

Michael, I'm also liking your idea for cone bearings into bronze. Any idea of the best angle for such cones?

Steve.

In the potts article, MEW 73 the included angle is given as 8 degrees. It has a double cone at each end as per Michaels suggestion.

Geoff

07/01/2019 19:53:14

Hi steve,

MEW issue number 73 has a article on a re designed Potts milling spindle..

The spindle and the housing have been modified, based on a illustration in a watchmakers book by Donald de Carle.

Looks very tricky to make but the author of article maintains it would be very accurate and suitable for high speed work.

It uses double opposed cone plain bearings. It is slimline design and like I say not easy to make but it may be of interest to you.

I have a copy of the magazine. You can have it for postage (paypal £2).

Message me if you are interested

Geoff

Thread: small cast iron flywheel
18/12/2018 12:54:42

Hi All,

With reference to the last post, I bought a Stuart flywheel.

A little smaller at 3 1/2" but should do the job.

Not sure how to hold it for machining as there was not an extended boss in the centre.

Used the method shown below. Perhaps a bit long winded but worked well.

The plywood disc has a square shoulder turned and the diameter is a snug fit on the inner rim of the casting, tapped it on with a copper mallet up to the shoulder.

img_3612.jpg

img_3611.jpg

Geoff

Thread: Jason's Firefly .46 Build
11/12/2018 13:46:13

Peter,

If you don't want to make a stepped broaching tool you could make a keyed driver instead.

I made one for my firefly. you would of course have to mill a keyway slot in the crankshaft.

If you go back to page 5 in this thread you will see the driver and crankshaft with the key fitted in my parts photograph.

Geoff

Thread: Interests other than Model Engineering
04/12/2018 07:20:42

Football, cricket and golf, in that order.

I played football until I was 35, cricket until 55 and golf I started at 11 and still playing.

The latter is the main reason why I make such painfully slow progress with my model engines. I spend far to much time honing and fine tuning my golf swing instead of honing and fine tuning my engines. My choice though, I only have myself to blame.

Geoffi

Thread: Steam Engine Number One
25/11/2018 11:11:50

Hi Iain,

One last post from me with a diagram I did last night.

As I understand it, you have a cylinder whose bottom hole is s slidefit for the piston ron and the top has a registration plate which fits into the underside of the plate.

Not quite like above Iain the piston rod guide is separate from the cylinder. The register is on the underside of the top plate.

Have a look at the jepson drawings on plans-for-everything.com and also the drawing with this post.

Hope it helps you Geoff see also the photos of the cross head

20181125_103346 (2).jpg

20171106_134957.jpg

20171106_103752.jpg

Thread: Morse taper sleeves
24/11/2018 11:01:59

Hi Larry,

All that matters is that it fits the gap between the sleeve and the arbor. ????

Don't quite follow the above Larry. I can vaguely see what your doing, the split collar forms a rigid face which you drive wedge against but not how it's actually used.

Now you have hang of posting pictures how about some more showing the clamp in use, I'd be interested

Geoff

Thread: Jason's Firefly .46 Build
24/11/2018 10:52:34

Well done Peter,

I'm glad I'm not only one who made mistakes making this engine.

I eventually took mine apart re lapped the bore and made a new piston and con rod, to improve the performance. I cu'd the lapping of the piston into the bore first time round, second piston was a much better fit.

How about some pictures of your engine, love to see some

Geoff

Thread: Steam Engine Number One
22/11/2018 15:45:53

Hi Iain,

I have been looking at your plans. This engine is similar to one I made last year.

Could I make the following suggestion regarding cross head design which you may wish to consider.

Your first drawing shows 2 cross bars which support the cylinder block. Why not replace this with a plate across the top. This plate would have a hole in the centre for the piston rod guide. The top of the piston rod guide would locate in the bore of the cylinder and that would of course register the position of the cylinder.

The under side of the plate would need a female register turning which truly concentric with the hole in the centre. The cross head guide is made from square stock turned round for most of it's length. On the top of the cross head you would need a male register to match the one in the plate.

Here a two pictures from my picture flle, Jepson Engine. Geoff

20170822_080636.jpg

20170816_123316 (2).jpg

Thread: Another new mill
22/11/2018 12:36:59

img_3599.jpgHi All,

Well after two weeks and a few small jobs I have to say I'm really pleased with the SX2P. It will certainly meet my needs for some years to come. 8.5 out of 10 at least.

Big downside, definitely the torsion arm. I can fully understand why owners are replacing with a gas strut. The strut gives stability through the full range of vertical travel, around 220mm.

As you can see I've replaced it already, the strut arrived yesterday and it was on the machine by 3pm,

img_3597.jpg

I know Ron (Laden) will be interested as may others, The strut was supplied by SGS engineering, 15mm body and 6mm strut. The product code is GS6-15-220-250 and the load is 120 newtons. The end couplings selected were the ones coded T5. I had to shorten these to make the strut fit the space, no real problem.

I chose 120N as the from the reviews I had read the person who used 60N said it was not enough and Howard Winwood in his Arc review suggested his at 150 may possibly have been to much. I'm happy with the 120N

In case anyone is wondering, no, I did not take a chunk out of the vice. I inherited the vice some years ago, already damaged.

Geoff

Thread: Valve timing
19/11/2018 20:18:49

http://www.plans-for-everything.com/hen_steam_engine_plans.html

Hi Alan,

Have a look at the above website.

Scroll down until you see the JEPSON engine.

Download the drawings and have a look at the adjustable cam design.

It is a simple "pinch" clamp, very effective, Takes a little time to make but much better than a grub screw.

Geoff

Thread: Drummond M type
09/11/2018 16:09:44

Hi Bamber

Is your lathe bench mounted or is it on the Drummond stand.

If bench mounted the the duplex designed countershaft in the earlier message is a good design, not simple to make but if you have the time and facilities is well worth making. If you pm me I can let you have detailed drawings..

I assume your lathe uses flat belts, if so and the lathe is on the Drummond stand then the L H Sparey design is fairly easy to set up. You would need to get a copy of his book to see what the design is all about

If you have flat belts it easy to convert to vee belt drive but you would need to get the vee pulley parts from the later myford made m type

Geoff

Thread: Another new mill
08/11/2018 13:33:18

Hi Martin,

Your mill looks good, enjoy it!!

Mine arrived yesterday as well.

Fresh out of the crate and after a quick inspection all looks good. It's heavy, I like that.

I was aware the mill has some "issues" e.g. the sprung arm to steady the head and the amount of play in the fine feed.

The first one, I may at some time replace the arm with a gas strut and the second, well I would like to add DRO's to the mill so that should resolve that issue. Not just yet though let's do some modelling first!

Geoff

img_3595.jpg

Thread: pneumatic fittings
05/11/2018 12:31:03

Hi mick,

How about some more information? photos, suppliers.

Thread: Another new mill
03/11/2018 08:32:36

Hi Gents,

Thank you for your replies and also, Mark, Martin, the advice and information.

All duly noted.

Geoff

02/11/2018 16:25:39

I dont think you will be disappointed Geoff, as you have maybe seen from the start of this thread I have Martins ex SX2P, it is only 18 months old and like new. I am a beginner but already I can see it opening up all new horizons when it comes to model engineering. Enjoy it when it arrives.

I will Ron, I will.

I am planning to bench mount it but having seen the stand that is available from Arc I am having second thoughts. I'll see how it looks on the bench first.

Do you have the stand Ron? or anyone else?

Geoff

02/11/2018 14:30:54

You will gather from the above I have a great regard for Arc, they are easy to do business with, normal disclaimer applies.

Hi Martin, couldn't agree more, every purchase of mine from ARC has been spot on in all respects.

I would imagine my purchase today, a Seig sx2p mill, will also meet those same standards.

Well I just had to have one!!!! My vertical slide days are over, at last, yipeeeee!!!!!!

Geoff

Thread: permaglide bushes
31/10/2018 13:20:57

Hi All,

Has anyone any experience of using these. I thought about using them as main bearing inserts to carry the crankshaft on my new engine. Crankshaft would be 8mm dia mild steel or possibly silver steel. Engine will need to run at low and high speed Geoff

Edited By JasonB on 31/10/2018 13:26:02

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