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Member postings for Bob Stevenson

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

Thread: Robot Wars
21/01/2020 08:30:31

The BBC abandoned it because it had too much robotics, electronics, materials and engineering, and young people were getting inspired....not much good when you are trying to get away from anything gritty and hands on.

Thread: Gathering pallet
21/01/2020 08:18:16

Don't overthink it....you only need a very short length of 'D' cutter to taper the hole so don't get too carried away filing up a long taper flat...... Just harden the end of the piece and temper to 'straw' then work on the edge of a fine stone until you can see that you are half way....may need to use a glass to see properly, then ream the hole and keep testing with arbor until you are pleased with the fit.

..............For a 1 degree tapered hole you could, alternatively, simply turn up the taper in brass, coat with an abrasive such as 'autosol' and just polish the inside of the hole until you get a nice fit......only do this in the lathe or similar so that it's accurate and the pallet sits nice and square.

21/01/2020 00:36:37

I've not made the Timmins clock but my standard method with all such items is to make an extra tapered component while the lathe is still set to the particular taper and then use the second one for making a 'D' cutter so that the female component might be easily made to an exact fit......

Thread: Lathes as bling!
17/01/2020 19:39:50

Interesting topic......

I have noticed a similarity between the expensive camera owners and the 'bling' lathe fraternity. I would defend a persons right to spend his money any way he wishes, however, I'm minded of the American landscape photographer (Ansel Adams?) Who said; "there's nothing worse than a sharp photo of a blurred subject".......

I personally know of at least four sparkling expensive lathes which are the pride and joy of their owners but which are basically never used for anything serious. Two weeks back I was shown a 'washer' that had been turned on a Schaublin 102 lathe that was a different thickness across it's width and when I brought this to the attention of the 'turner' was told that it did'nt matter and had been made quickly "without any thought".....

Thread: Silver Soldering Brass
15/01/2020 15:55:37

I also use Seivert, I got mine from CuP Alloys who have some very informative videos on their site.

Watching beginning clock repairers in the workshop I notice that they tend to allow their heat to escape when attempting silver soldering for the first time.........CuP Alloys can supply some 'heat blanket' which you put over the piece and then heat thru the side gap...it allows very little heat to excape so ideal soldering temp is arrived at quickly and easily.

Lastly, silver soldering gets much easier the more you practice so sup up some bits of brass and have a play. The costs in gas/solder/time etc will be handsomely repaid.

Thread: rolling brass strip in the lathe
14/01/2020 23:35:12

Cut the brass carefully to the right length for the finished diameter using rxpi (at 3.142) file edges nicely as this will help later.....place on hearth and heat using a 'brushy' flame...keep the flame moving until the piece is just glowing..ie not too bright or red......if the torch is small it's ok to start at one end and work to the other but keep it moving.....allow 'glow' to go and then cool under the tap.....

Find a suitable former for your diameter...ideally a little smaller than the finished diameter.....a lathe chuck can be good but always use several layers of gaffer tape to get to the exact diameter...this is both for exact sizing and also to protect the brass surface using just your FINGERS bend the brass round the former in one operation...use a hardwood block to get the ends to meet nicely, or use the clamping of a 'workmate'.

Carefully file the join using a flat file (I use a warding file0 until there is no light coming thru the join when you hold it closed.......silver solder. In all probability there will probably be some slight heat distortion so return the piece to the former for final pampering....If the walls twist use padded pliers to gently untwist so that a perfect fit onto former.

Thread: Does a particular thread hold better into brass
12/01/2020 18:57:02

BA was only formulated In 1893 (I think?) so relatively recently in horological terms. It was designed at the behest of the GPO by Mr Lehman who set up it's production by his company Lehman, Archer & lane....horological use came later

 

Before BA, and in the great era of English clockmaking the individual clock makers made up their own 'thread plates' and taps, as did other 'techy' trades such as gunsmiths and silversmiths etc. to make a thread plate you first need to make the taps..one method is to wind wire around a carbon steel pin and then file the outline to give the thread pitch.....then you only need to cut the flutes and harden and temper. This method served the industrial revolution and up to the victorian era.

 

When engineering 'by the seat of your pants' like this you need to be an intuitive worker....in brass one needs to be aware of the softness and keep thread pitch large enough to give strength.....

Edited By Bob Stevenson on 12/01/2020 19:00:42

Thread: John Wilding Elegant Scroll Skeleton Clock
07/01/2020 22:18:48

I can' find that title among the wilding books..... There is the ':Large wheel skeleton clock' book mentioned at teh start of this topic and there is 'How to Make a Skeleton clock' isbn; 0 9503512 21 1

 

Inn the latter book mentioned above the first chapter is headed; "an 8-day Skeleton Clock". Several members of Epping Forest Horology club have made the clock successfully and I have not heard of any 'duration' problems. However, I have made a set of wheels, barrel & fusee recently to use in another clock of my own design.....there are many inaccuracies, gaps and problems in the book that I have found, and in fact will not use a wilding design/publication again for this reason. Among our members the wilding books have attracted increasing criticism in recent years....so questions;...

 

.......A couple of years back Wilding published an article on 'Horological Journal' mentioning that his fusee patterns would benefit from being smaller but did not intone by how much!

 

1) What isbn number are you working from?

 

2) How long does your clock run for?

 

3) What is the actual title of your book?

 

4) in mentioning a bigger barrel,, did your book happen to mention a bigger spring?

 

 

Edited By Bob Stevenson on 07/01/2020 22:38:19

Thread: Watch servicing
06/01/2020 10:41:24

Epping Forest Horolgy Club has a strong watch following with separate well equipped watch workshop for 14 students at a time complete with large projector screen taking microscope feed from tutors bench etc. We have about 50 watch fanatics (& pro repairers) of all flavours from ancient pocket watches to WWII divers watches to Rolex adjusters to people actually making watches from scratch! We are 15 miles N.E. of central London near to Epping town (central line)

05/01/2020 13:56:46

ETA 2824 movement........I have no interest in watch matters, but do I remember clearly that this is a readily replaceable movement and cost about £60...?? it could be cheaper in the long run to tip the movement in the bin and whack in a new one, probably the same/nearly the same cost as a 'service' charge.

......Might be wrong as i'm no 'watchy' however at EFHC we have a whole watch section and they buy movements in bulk such as that in TAG-Heuer which are between £40 & £80 (in £1500 watch!!)

Thread: Stanley Blade Lathe Finishing Tool
26/12/2019 10:11:02

Yes, I used to do this a lot when making brass instrument mouthpieces as turning the inside of the 'cup' is tricky for the beginner. I have used it when making clock pillars but have moved on now to a collection of steel washers with different edge modifications and sizes...this is a trick I gleaned from a visit to Boosey & Hawkes when they were still around and making brass instruments...

I love the vid, by the way! Not thrilled by the use of the knurling tool decoration but that man knows exactly what he's doing and the results speak for themselves.

Thread: Making a superglue chuck adapter for brass wheel
25/12/2019 14:39:19

...If you do really feel the need to cut clock wheels as crudely as this then make it a bit easier and simply screw the wheel blank to the wooden "arbor" with screws thru the places which will be eliminated in crossing out.....

..........Cynoacrylate can be readily freed on delicate clock parts by gently boiling in water for about 10 to 15 minutes, where on the glue suddenly gives up. If the parts are not delicate then a small flame from a lighter will suffice, usually.

24/12/2019 10:43:41

The best way to work on clock wheels is to use an off-cut of clear plastic sheet about 8 to 10 mil thick...it's not critical...cut roughly square (I use a rectangular piece now)....mark scored lines from corner to corner and mount in 4-jaw eoughly centred. Bore out to exactly the INSIDE dimension of the crossings you wish to make,....then cut a 'rebate' to exactly accept the wheel with a snug push-fit....thus the wheel is exactly mounted on centre of lathe....

Now bore the centre whole to fit the wheel collet you have made.......

Now remove from lathe and use the internal diameter as the filing guage for the inside of the crossings...the file will slip nicely off of the plastic as you get to the right place......a steel straight edge can be bolted across the piece so the the 'spokes' of the crossings can also be filed accurately.

The wheel can be put back in the lathe at any time by 'clocking' the inside bore of the plastic holder.

Thread: Astro-skeleton clock project
06/12/2019 21:12:51

https://www.buchananclocks.com/history/

Originally 'Buchanan of London'..then Buchanan of Chelmsford and now Buchanan of Melbourne(?) although the website claims a S.African origin....

Thread: Lathe lighting
06/12/2019 11:24:47

Robin,....Pretty much everyone here is "self-taught" in one way or another, and that includes the pro machinists.

I don't use halogen anymore and have been pleased with my larger LED lamp holders which have spring clamps....I often use the rod which once held the chuck guard. I use 'daylight' LEDS (6400k) and the larger bulbs give a nice smooth light without any aberations in the beam, which annoyed me no end with the halogens when doing fine work.

Thread: Case Hardening
04/12/2019 21:18:02

Early American firearms such as the Sharps rifles have mottled colour patterns due to their being case hardened using bonemeal....the parts were packed in the bonemeal, leaving no air spaces, inside iron tubes and brought to red heat.

Thread: Mini Lathe Upgrade
23/11/2019 17:52:46

I used a Conquest mini-lathe for about 10 years but changed two years ago to a Warco WM180 which is a sibling machine to DB7. I liked my mini-lathe and have defended mini-lathe on this forum, however, the WM180 is vastly superior in just about every way and I have been delighted with it's many improvements over mini-lathe.

Thread: Rake angle on Cutting Tools.....memory tips???
20/11/2019 22:40:30

Honestly Chris I think you are making too much out of this.....I have been turning most of my life and aquired my first real lathe about 40 years ago and I'm not really sure what 'positive' 'neautral' & 'negative' actually mean in lathe tool context ....I'm pretty sure that you don't need to either....just get a copy of 'The Amateurs Lathe' by Sparey and in there you will find the relatively few tool designs needed to make just about anything with excellent surface finish etc.

look in the book, grind up some HSS and get making clocks!...add more special tools as needed.

I spent a chunk of the morning in my clock club workshop making a centre arbor for my latest clock....I tried out a Pultra 10mm lathe which was used in WWII by Handley page to make rivets for the 'Halifax'....I really enjoyed myself and was able to get a brilliant finish using a 'knife' tool I keep in my box....touched up the edges with my 'Eze-Lap' and away we went. The only 'choice' I made was selecting a tool with some top rake suitable for steel.

Just get at it Chris, you'll be OK!

Thread: Watchmakers lathe
16/11/2019 19:05:15

Watchmakers lathes are (usually) in either 6mm collet size or 8mm and were made common by the German maker 'Lorch'....however, in practice these collets are often not very interchangeable from make to make.

 

For clock making a larger lathe such as the old 'Pultra'(10mm) or Schaublin Swiss lathes are probably more useful.

 

The best way to mug up on all of this is to find a copy of 'The Watchmakers Lathe' by Donald D'Carle.  This has been reprinted a couple of dozen times and later editions include info on model makers lathes too

Edited By Bob Stevenson on 16/11/2019 19:07:16

Thread: 8mm live centre
13/11/2019 23:07:58

https://www.youtube.com/watch?v=L0ZTw5J8oTE

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