Member postings for Clive Foster

As Jason says even the flat end tool is by no means easy to grind in smaller sizes.

Objectively you are in micrometer adjustable jig territory. The great advantage is that measuring how much you have taken off the sharp pointed tool you start out from is relatively easy and, if the flanks were jig ground at the correct angle, the width must be right. So even if things don't work you know exactly what you have giving a reasonable change of figuring out what to do next.

Being able to reliably get "the same" wrong result is always a better start than wondering "what went wrong this time?".

But it all starts on the drawing board or CAD screen. Home Shop Guy hasn't a hope of measuring this stuff so all he can do is carefully work out what is needed then establish reliable techniques to do it.

Had a few "D'oh twot!" moments after carefully plotting out what I'd done on the CAD to prove that it was right only to discover the connection between the effects of what was done and correct was somewhat nebulous.

Clive

Quality inserts are generally ground to a specfication so they cut a book thread with book infeed. As do the Johannesson / SKF / Dormer 3/4 circle chasers I prefer when screw cutting external threads. Which makes life easy if you re lucky enough to have them.

Hand ground tooling will almost certainly be too pointy so extra depth is needed for clearance. Which can either be added as an empirical, usually works, factor as Dave does or you can try being a bit more scientifically investigative about things as I do when using the zero-to-zero threading method. Functionally zero-to-zero is pretty much equivalent to using an ELS for threading as you stop at a depth pre-determined during set-up. If that initial depth turns out to be too shallow I make successive slightly deeper passes until sufficient clearance is obtained for parts to screw together. Just like CNC and and ELS the zero-to-zero method lets me add feed in accurately determined increments so that once success has been achieved I can adjust the set-up parameters to compensate so all subsequent threads are right. In an important application I use increments to something close to the specified thread tolerances so the difference between the last doesn't fit and first does fit threads will be small enough that the does fit one will be within tolerance.

Alternatively you could cut flat bottomed threads where the root is flat rather than curved. The flat width being sufficient to encompass the correctly shaped thread from end. Using calculation and drawing board or CAD techniques the difference in depth between a sharp point and a flat of the correct width can be determined. As can the infeed depth needed. Creating the tool is a simple(?) matter of grinding a sharp point of the correct angles then flattening the end by the desired amount. Something that is easy to keep track of by measurement.

Clive

Puddleglum

It all depends what you want to do. Fundamentally you need enough room for the jobs planned, long enough travels to work on them and enough set up flexibility to get at all the faces. Not forgetting affordability and the need to accommodate the beast.

For first time buyers the big trap is forgetting that pretty much everything goes inside the workspace so things like vices and other work holding significantly reduce the space for the job. Long tools like larger drills can be a particular problem on smaller machines. A set of stub drills can be real handy here. Who needs a 6" long drill when your biggest job is only 1" thick!

Smaller hobby mills have to be made at a price the ordinary guy can afford which inevitably puts limits on performance. The art is to pick one whose serious limits are outside what you want to do. Lighter cuts, smaller tools and more passes are a given for small machines tho'.

For example tilting heads man for a more flexible machine but tend to reduce rigidity. The need to reset after working at an angle often dissuades folk from exploiting that feature. For small jobs tilting the workpiece is generally not that difficult anyway. So why pay for what you won't use. Another example is the popular round column drill-mills that put a lot of workspace into an affordable and relatively compact package. Major issue is that it's hard to keep the head in dead nuts alignment if moving the head up up and down so, all too often, the useful vertical envelope is limited to the quill travel. Back to the coping with long drills and short cutter problem.

When choosing it's easy to concentrate on what the potential object of your affections can do.

Which may cause you to overlook something it can't do that will end up being important.

How do I know!

Before finally putting money down its a useful exercise to compare your choice against a Bridgeport which can, probably, handle anything Home Workshop Guy can lift by listing out what the Bridgeport can do but your choice can't.

Hopefully there will be nothing of significance on the can't do list beyond sheer size but if there is at least you have been warned and can look into work arounds. Generally folk have figured out work arounds for the limitations of all the smaller hobby machines. A bit of internet searching will find the answers so its just down to whether the work around is something you can handle.

Clive

Edited By Clive Foster on 20/05/2023 08:25:19

Diogenes

175 kg per shelf stops being hard to believe the moment you consider the (non) engineering of the common smartly faced chipboard bookshelf sets from Ikea et al. Almost a yard of books supported on 4 wimpy little pins pushed into the uprights. Books by the yard are heavy, really heavy. I'd be scared to try and calculate the loadings involved. Far as I can see the support engagement is about 6 mm long by 4 mm wide per pin, assuming a little bit of load flow from the flat board around the pin. Doing the maths seems to be tempting fate that if I did figure out thing the shelves would realise they actually aren't strong enough and collapse. Something over 9 m length by 2 m high of fully loaded bookshelf its a lot to re-home!

Kit built furniture always seems vastly under-engineered for the job and I hate the way everything flops about until that last part slots in making it a stiff structure. But the Argos bed in teh spare room did get some extra brackets.

I guess the old adage that, for smaller projects up to "needs a few people" size the old adage that if its "stiff enough its strong enough". Peering under a modern car is a (worrying) education into how much load can be passed through how little material if you are clever about it.

Clive

Michael

Wikipedia tells you about all a user needs to know about TWAIN :- **LINK**

https://en.wikipedia.org/wiki/TWAIN

Basically the TWAIN working group exist to create an maintain a set of drivers for interfacing between a computer and an imaging device independent of the drivers offered by imaging device manufacturers. Several imaging device makers are have a formal attachment to the TWAIN as well as creating their own driver and interface software.

TWAIN drivers tend to offer a more basic functionality than the device makers own which, especially these days, tend to have lots more in the way of bells and whistles which may or may not be useful to the individual.

TWAIN drivers generally continue to work just fine when device makers own fall by the wayside by not being updated for new operating systems.

From a user perspective its just a matter of downloading a TWAIN driver and selecting that in preference to the makers version.

TWAIN comes from a Kipling quote from the Ballard of East and West "and never the twain shall meet". Its not an acronym.

Clive

Les

Regrettably little I fear.

Fundamentally a collectors item, if there are folk that collect such things, because it's a functionally poor design and not actually that useful. The base moves freely once you release the toolholders and setting tools to height is even more of a faff than shimming with screws both underneath and on top to adjust. If you fit two toolholders they both face the same way so getting in the way of the job is almost certain.

One has to wonder what sort of wacky baccy the designer was putting in his pipe and what Burned management were using for sugar in their tea. I reckon they'd have done a darn sight better selling a system based pin a fixed, indexing base with two slot blocks to go on top.

Clive

+1 for the wall hangers and bracket system so long as the walls are strong enough. London pattern brackets direct to the wall are inexpensive and OK if your loads aren't going to be too great. I use them occasionally but not my favourite as getting the uppermost screw in is always a faff. No clearance for the drill / driver so extensions needed in front of the bit which doesn't help getting the screw straight.

I prefer the good quality green waterproof flooring board for shelves. No splinters like affordable plywood so often has, doesn't warp like solid timber can and the slightly rough surface helps stop things rolling off. The workshop shelves I made from that material are single ones about 6 ft up so I put an aluminium angle finisher across the front with about 1/16" or a bit more upstand. Looks nice and the little ridge means you have to properly lift stuff off.

If you are sure you wont need to adjust the shelf spacing extra supports outboard can be arranged using redundant con-tube or similar.

Given the choice, and funds, I'd use the 1" square tube "speed frame" knock together system. Looks good and really strong., But £££ so it darn well ought to. Couple of nice racks made that way in my loft using "obtained" material.

Clive

Maybe it would have been worth getting that long reach stapler for £5 last year even though I only thought I might find it handy.

By my standards 12 months from "Good price, I'll get one just in case I ever need one." is positively supersonic.

Longest wait from "handy buy" to "actually" so far is about 25 years. Some things still waiting in the cupboard after over 30!

Clive

Hmmn. I seem to recall Geo.H Thomas warning against relying on inexpensive thread gauges as "some are pretty ropey".

Probably more about the thread form than actual pitch count.

A good gauge will seat fully into and accurate thread essentially blocking light transmission, or at least leaving an even line of light should then thread be shallow, when studied under magnification. A not unimportant asset when trying to distinguish between 55° and 60° threads. Way back I had a couple of cheapies that were merely just about OK. Didn't realise how poor they was until I could afford to upgrade to a combination of M&W and Starrett ones.

BA is now an odd ball thread so the gauge market is declining so one wonders if makers find it worth producing quality gauges as quality costs more and small market drives the price up even further.

For what is likely to be one time job it doesn't seem worth dipping into the inevitably inadequate funds available for Home Workshop duties to buy a gauge when a simple process is adequate to do the "sheep or goats" level identification needed here.

Clive

Further to what SillyOldDuffer says 0 BA and 1/4 BSF are dangerously close in size. 0 BA screws into 1/4 BSF but is very slack so the joint is weak.

Whitworth goes down to 1/8" diameter, 40 tpi in once common small sizes so its not just for big stuff.

Maybe I'm a minority of 1 but I like the small Whitworth sizes.

Clive

Agree with Resetter that it's likely to be 6 BA. Not uncommon for nameplate holding and similar duties.

Nominal outside diameter is 2.8 mm and pitch is 0.53 mm.

As you already have screws one way of estimating thread pitch is :-

1)  start the screw by a couple of threads

2) measure the stick out from top of head to the drill body

3) screw in by as many full turns as is convenient

4) repeat teh measurement from top of head to body

5) subtract the second measurement rom the first and divide by the number of turns

6) result will be close enough to true pitch to identify the thread.

Clive

Edited By Clive Foster on 15/05/2023 22:28:36

Mine had the centre 10 pages transposed to the beginning and end of the magazine text proper, ie 5 pages at each end.

Fixed by using paper clips to hold the two transposed sections together, removing the old staples, putting things in order and re-stapling. Would have been easier I had a long reach stapler but one of mile flips out to 180° so I could drive them through into a drawing pad then flip over to hand bend the ends. Good enuf for government work.

Clive

Edited By Clive Foster on 15/05/2023 15:23:57

Bazyle suggests the concrete will need a few months to properly dry out and reach full stability. Which is standard engineering if you want high strength. But in practice it needs much less time to go off sufficiently to be a stable floor if its not completely hermetically sealed.

My flooring boards went down about a fortnight after the concrete. Just long enough for two of us to build the timber workshop and clad the walls both inside and out. I imagine the need to breathe was why we left the surface with tamping grooves.

Folk buying new build houses a on a small estate just up the road have found out the hard way that building on concrete that hasn't gone off sufficiently. Two years in and major problems with cracks. I doubt if the concert was down three full days before building continued. Big name developer with one of those silo things on site for pumped delivery of the concrete. Oodles of chemical additives no doubt to keep it workable which which doubtless plays merry hob with setting to full strength.

My expensive waterproof tongue and groove chipboard flooring is unfazed by the machines sitting on it. Neither marks or depressions appear if I move things. I have full on workshop machines so the weights are significant. Smart & Brown 1024 lathe at approaching ton and a half, Pratt & Whitney Model B 12" x 14" around a ton and a quarter, Bridgeport mill at about a ton, Elliott 10 M shaper at around half a ton along with a Rapidor saw and Pollard 15 AY drill, both "not light", something in the quarter ton region I guess.

I suspect the economy range and non waterproof versions would not fare as well. The stuff intended for lofts and the like certainly wouldn't be up to the job despite being perfectly satisfactory at what its made for.

Clive

Generally latex self levelling coatings have a modicum of flexibility helping to reduce cracking should anything move. The epoxy type tend to be much more rigid with a greater load carrying capacity and, often, a tough colour included so no need for subsequent painting.

For your purposes differences are academic. Latex self levelling is amply strong enough and chances of any movement sufficient to crack epoxy are remote. Realistically selection is down to cost and performance down to how well it's laid. Probably the builder is suggesting the material he is most familiar with so odds are he is more likely to do a better job.

I'd not use either.

When I built my big new workshop nearly 20 years ago I was advised to use high quality waterproof tongue and groove flooring board, the green stuff, direct on the concrete.

Which turned out to be good advice.

Still going strong, looks OK despite the mottled green having faded unevenly along with a few oil and paint stains. It's stood up just fine to machine moving but I have put a few scorch marks from welding splatter in. Nicer underfoot than concrete, levelling compound or epoxy too. We took great care when finishing the concrete to get it very level with shallow, close set, tamping grooves. I was told that the board would sit better on shallow tramping grooves being a blessing to accommodate small variations better than on a "levelled" surface.

Splashed out on the best i could find as cheaper breeds aren't as durable. Workshop is 15 ft by 36 ft (ish) and I did the attic space too so I bought an enough to get pallet pricing rather than per board. Leftovers made nice shelves and cold area workbench tops. The slightly rough finish being excellent at slowing dropped parts trying to escape.

Clive

Edited By Clive Foster on 13/05/2023 13:17:18

A Bridgeport is primarily tippy from side to side. If supporting from beneath using rollers, rails or castors unless the surface you are moving over is in very good condition and decently flat it's well worth fabricating some timber supports to strap under the ends of the table. Set them so they skim the ground by an inch or less.

If it does try to tip the support will hit the ground before its gone far enough to worry or generate significant forces on the table and gibs.

It will then sit there nice and stable whilst you figure out what to do next.

I was very glad that I did that when moving mine in.

The path round the right back corner of my house has an off camber twist so trouble was expected and advance preparations seemed wise. To no great surprise it tilted gracefully part way round the corner and settled nice and stable on the downside support at a barely visible angle. After a tea'n think break we laid some extra plywood sheets on the grass alongside the path where the supports would skim and continued the move leaning on the upside of the table to keep the downside support clear of the plywood sheets. Adjusting the knee height as needed to keep the gap central. It took surprisingly little effort to keep it level. Turned out the rest of the path was by no means as level side to side as it looked so most of the remaining distance was covered in the same way.

These days I reckon sliding a machine along steel parts laid rail fashion along the direction of travel is generally a better way of going about things than improvised rollers or castors. Especially with a come-along as advised by Jelly. Not used the idea outside, and probably never will as my big machine moving days are over, but it works very well in the workshop.

Clive

Its not outrageously difficult to break a Bridgeport down into lumps that can be handled by an engine crane and dropped into a decently heavy duty trailer.

Preferable option is some form of gantry hoist. Lift off the ram, head and turret in one lump, slide off the table, lift the column, knee and Y slide into the trailer as one unit. Thats more or less how I did mine but I left the table on. Which had advantages and disadvantages. Advantage was that I could fix timber H sections under the table to stop the machine rocking. Disadvantage was that the the table got in the way going round the turns from front of house to backyard shop.

If engine hoisting pull the head, ram and turret separately.

If you have to roll it any distance making a super duty 4 castor dolly beats the heck out of skates or rollers. Much more controllable. Mine has 3" diameter by 3" wide castor wheels.

That said calling in the professionals makes life easy. I imagine Anyvan quoted you for half a days work by a professional outfit. Fort that I'd expect it taken right into its new home. I've been very satisfied when using Anyvan but I think a Bridgeport is a bit outside their usual range.

Clive

For folk like us really sharp is much more important than correct to book clearance angles.

I've pretty much given up on any form of rake on the top for normal work leaving the top of the HSS blank flat. Saves mucking about with tool height. Whether by shimming or QC adjustment. In practice it limits the sensible depth of cut to around 50 thou / 1mm, unless I turn the coolant on, but a couple of extra passes are rarely a problem most of the time.

Sharpening on the periphery of the wheel to give a curved hollow grind makes it really easy to touch up the edge to a sharpness approaching a decent razor blade. The slipstone stone or diamond sharpening stick is supported only at the top and bottom of the tool so it is inherently stable with no tendency to rock. I reckon most inexperienced folk, and fair few experienced ones on a bad day, make a tool ground with a flat face worse rather than better when touching up by hand. It's really difficult to avoid rocking when working freehand. Most folk would probably be better off if they had some form of roller guide, as used with plane blades, to fix the angle.

Once you have a noticeable flat below the cutting edge it's dead easy to re-sharpen off the periphery of the grinding wheel. A sturdy toolrest is great help. Many of the affordable imports have distressingly flexible ones spoiling a fundamentally good grinder.

Ages back I purchased a Creusen grinder on an RJH vacuum filter stand with only one toolrest. So I measured up the remaining one and made a slightly improved copy. Did proper drawings with full documentation and photographs of the machining taken intending to write it up for MEW figuring it could easily be adapted to just about any other breed by simply changing appropriate dimensions. Still have the files and picture but they rite up never happened.

Clive

A single layer of clingfilm wrapped round a magnet has negligible effect on grip but makes it far easier to get ferrous swarf off.

Carefully unwrap the cling film and the swarf stays with it leaving a clean magnet behind.

Clive

In these days of relatively inexpensive dial gauges and indicators it's surely more sensible to make a bench "tool setter" device to directly measure the actual height of the cutting edge and calculate the shim thickness needed.

Fit a dial gauge with an elephants foot, attach to a suitable upstand fixed to an adequately flat base and the worlds your mollusc. I imagine the colour coded plastic shim sheets will be up to the deed on our smaller machines so keeping track of what shims you have becomes easy.

Not forgetting some thicker ones if you need to build up seriously for smaller tooling.

That said I prefer sharp internal corner angle, whether bought (alloy extrusion is usually good) or welded up, for rough setting of undersize tooling as the upright side helps keep the tooling centred under the clamp bolts. A trick that works just as well with QC systems like my Dicksons.

The more economically minded can do adequately well with a long lever pivoted close to the short end and a ruler on the long end. If you can read 1 mm a 1 to 10 ratio gives 0.1 mm, 4 thou, resolution. Well beyond what can reasonably achieved with a centre height gauge or Dave's method. Which latter I loathe in principle because its accuracy decrease as the stock gets larger. Around 1" or 25 mm diameter is the easily useful limit. Its ability wreck a sharp edge being merely a side benefit!

For insert tooling it's just a pure mathematical exercise reading off holder and insert dimensions from the data sheet to work out the shims needed. Tolerances for any half decent system are way better than you can achieve with a centre gauge.

For me the most convenient type of centre height gauge is the optical style. Basically just a thick piece of perspex held up right by a suitable base with a line scribed at centre height on both sides. If the two lines and the tool tip set nearly touching the blade eye up coincident the tool is on centre height. The coincidence principle means it can be viewed from a distance without noticeable error. Shove a mirror on the back at 45° and you can look down on it rather than along which is sometimes better.

Just the thing for setting QC systems.

Probably the easiest type to make too. So nice when really easy and really good come in the same box.

Clive

Rainbows

Interesting video but very much a conventional type of CNC turret lathe made small.

Ultimately I can't see the price /performance / speed / size ratios working out for a viable industrial "use several small cheap spindles" machine.

Way I looked at it you'd use cheap mouse power steppers to set the stops and something more husky, but still inexpensive, like a DC motor to drive the capstan et al. The trick is being appropriately clever to keep the price down and afford automated materials and parts handling. Whole thing has to be very "ap dependant" to avoid needing skilled tool setters et al.

10 years back when I took a preliminary look at the concept for reasons that seemed valid at the time it was all do-able, although the human interfacing wasn't going to be nice, but would have been twice or more the maximum viable selling price. Now I'm comfortably retired so another career doesn't interest me. Nor does making one to prove I can do it.

Clive