Member postings for Brian G

Perhaps our language is just getting more sophisticated?

I will leave it up to others to decide which of the available meanings to attribute to that statement

Brian G

Personally I would agree with that, but by the most popular definition (the impossibility of interbreeding or the sterility of hybrid offspring), two of them are different species. To a layman such as myself this is confusing.

Should "species" just be maintained as a convenience as rightly or wrongly it forms part of the traditional naming of things in the same way as we still use conventional current in electrical circuits? Alternatively, does the combination of genetics and morphology require the terms "species" and "sub-species" to be retired or reinterpreted in the same way as quantum mechanics did for "wave" and "particle"?

Brian G

The interbreeding definition may have been both explicit and simple, but unfortunately it is not definitive. The lesser black-backed gull cannot interbreed with the herring gull. Each can however interbreed with neighbouring species, which can in turn interbreed with another, eventually forming a ring of seven interbreeding species. Therefore the classical definition that you are attempting to justify says that all of those species are the same as each can interbreed with another, whilst at the same time says that two of them are not the same.

Brian G

Personally, choosing a mini-lathe, in our case an ex-display model, "sold as seen" by Warco, was a matter of risk management. Having researched a little, we knew what problems and limitations we might encounter and the costs in time and money that could be involved. It needed adjustment (particularly the motor mounts - the belt slipped making a noise that caused me to remove the headstock to examine the gears), but once this was done, and some minor adjustments carried out it performs exactly as expected. When I needed to order parts and accessories all it took was a phone call and they were with me the next day. Yes, the speed controller could blow (although given the volume of these machines that are sold, the absence of advertisements for replacements suggests it is unlikely), in which case I would probably be looking for a scooter motor, but there is no guarantee on the motor of a second-hand machine either.

Looking at the number of articles on the web detailing improvements and corrections to the Chinese machines, it is possible to get the impression that they are all at best "kits", but then again, a quick look at the number of articles on Myfords to be found in ME over the last half-century could make you think the same thing. As far as quality is concerned, unsurprisingly the components aren't going to be the best that money can buy (in the Cromwell catalogue an 80mm 3-jaw chuck is more than half the price of a mini-lathe!), but at least they aren't worn out by 20+ years of 40 hour weeks.

Quite apart from the fact that my son wouldn't have got most ex-industrial machines upstairs, for us the risks of purchasing one outweighed the benefits. In most cases the machine cannot be seen (or perhaps more importantly heard) running, and if some of the machines I used in industry were anything to go by, a bed regrind costing more than the mini-lathe might have been the least of our worries. I wonder how many machines we would have needed to look at before finding one that is both cheap and good? Even minor things like missing change gears could add up at more than £10 each. assuming they can be found.

Brian

Perhaps the mini-lathe is the Honda Cub of lathes. If so, I wouldn't mind a CD175. Neither is that powerful, and certainly not glamorous, but they get the job done without any fuss.

Brian

For A4 drawings I just use plastic pockets with a separate ring binder for each active project that also contains any material lists or amendments. I use the same pockets for larger drawings, making up a parts list and index first so I don't have to take them all out to find the sheet I want. In use they get spread out on any flat (or flattish) surface - to be honest, often an open drawer is all I can find.

I am a lot more organised with data than drawings, having printed and laminated back to back A4 copies of all the conversion tables, speed tables, thread specifications etc. that I use and punched three holes in the narrow end for two keyrings and a hanging hole. It makes a sort of endless board book so that I can just flip through to the one I want and it will lay flat on a bench (or drawer) or hang from a hook.

Brian

Can you mount the rotary table to an angle plate on the cross-slide of your lathe (or even bolt it to a bar clamped in the toolpost)? Even without a vertical slide it may be possible to offset the table to a position that lets you drill the holes, and the lathe bed may allow you more (horizontal) headroom than the mill.

Brian

Its a test or "tell-tale" indicator Paul, an ancestor of the dial test indicator it amplifies the movement of the tip by one or more levers rather than a gear. There is a rather complicated one here in Google Patents **LINK** and a simpler one in Wikipedia **LINK** .

There are quite a few on eBay, search Collectables for "test indicator -dial" and an undimensioned drawing and a description of a single lever tell-tale indicator in MEW 69 (November 2000).

Brian

(edit: remembered where I had seen the drawing)

Edited By Brian G on 07/11/2017 10:00:52

The Wayback machine still has a copy (with the Guernsey letterhead, which may explain its current absence). I have no idea how to attach a .pdf to a post, but it can be downloaded from here **LINK**

The running instructions are also available here **LINK**

Brian

Could you bore out the block and fit an eccentric insert to lower the worm onto the wheel?  Or perhaps more simply lower the entire block slightly by elongating the fixing holes?

Brian

Edited By Brian G on 31/10/2017 14:50:13

I assume he means turning the underside of the head down to the across flats dimension for a few thou so that it doesn't mark the paintwork as it is tightened.  As far as the paint is concerned it is then a cheese-head screw.  I keep putting off doing this to the screws on a 16mm loco but it is much tidier than washers.

Brian

Edited By Brian G on 31/10/2017 09:46:17

Could you use two layers of 8mm plate and sweat them together? Then the cutout could be made with hand tools.

Brian

I used to specify 7.2mm clearance for M6, with a hole spacing tolerance of +/- 0.5mm on greehouse components. It kept the reject rate down and didn't affect the building's geometry as the screws were used to secure parts together, not locate them.

Brian

One advantage of using the nuts to jack the chuck off of the flange is that it will release before the nuts are fully undone, so there is no risk of it landing on the ways, the sort of "sods law" event that is almost guaranteed should you forget the wooden block. To make it easier I have fitted longer studs to the chucks - the nuts can (and must) now be fitted before it engages with the register, which avoids a lot of the faffing around due to lack of access behind an 80mm chuck.

Brian

Oxford and Kennedy both do 5" mm/thou vernier calipers but things seem to get weirder as they get smaller.

Axminster list a 100mm Vernier caliper. Unfortunately, like their 100mm steel rule, it is metric only How much money does it actually save them to give it only one scale? **LINK** M&Ws 70mm caliper similarly is metric only. **LINK**

Farnell list a Hitec 100mm caliper, but the imperial side is in 1/128" - I'm not sure I could cope with that! **LINK**

Brian

Bought several Kennedy digital calipers more than ten years ago for work, one was in my desk drawer along with the calibrated test bars (now well out of date) and a dial caliper when the factory closed so I "disposed" of them. Dead reliable, and despite having both absolute and increment measurement and a display that never times out the battery lasts many times as long as those in the Aldi caliper I keep in my desk. Meanwhile, I am not even sure where the dial caliper is, it is so long since I used it.

Brian

Or perhaps 2.5mm or 3.5mm linoleum sold by the metre? **LINK**

I must admit it has me tempted, my dad's bench was covered in linoleum and was tough but didn't bruise anything placed on it.

Brian

If it is a new installation you could always cheat and use slotless round head screws (threaded rivets) like these **LINK** into a tapped hole.

Brian

I did that on a costing once Dave - ouch!

It doesn't seem so long ago that the pound was sufficiently healthy that the extruded price (without tax) in pounds was almost exactly the same number as the LME in dollars. Those were the days.

Brian

I wish. The LME is currently at $ 2128 which is £1936 including VAT, so I think the OP's price of £3000 was pretty good by the time the extrusion premium and stockholder's costs are included. I wouldn't be surprised to pay a stockholder at least twice that, they have to fund a warehouse full of frequently slow moving profiles - aluminium isn't just stocked in rounds, flats, tubes and boxes like steel. When I was buying aluminium, I used to pay at least twice as much to stockholders as I would direct to the mill, but it kept the line going so I wasn't bothered

Brian