Member postings for Howard Lewis

For inserts , and holders, try J.B. Cutting Tools.

The Cottages

Hundall lane

Dronfield

SHEFFIELD

S18 4BP

01246 - 4128110

[email protected].

As a customer, I have always found Jenny to be most helpful.

I used to have problems making telephone contact, having to leave a message on the answerphone.

Last time that I spoke to her, she said that the E mail was now up and running.

JB attend most of the shows, the next one, of which I know, will be at Spalding, 26/27th April, and then Harrogate in May. So if you can get there you can discuss your needs, face to face.

Also look at Chronos, Warco, Chester, or other major suppliers, as possible sources of inserts.

Howard

Eye halve a spelling checker

It came with my pea sea

It marcs for my revue

Miss steaks eye kin not sea.

Eye strike a quay and type a word

And weight four it too say

Weather I am wrong oar write

It shows me strait a weigh.

As soon as a mist ache is maid

It nose bee four too long

And eye can putt the error rite

It’s rare lea ever wrong.

Eye have run this poem threw it

I am shore ewe are pleased two no

It’s letter perfect all the weigh.

My chequer tolled me sew.

Interesting comments on QCTPs and their quality!

I keep wondering about one for my Engineers Tool Room BL12 -24 (Warco BH600/Chester Craftsman lookalike).

But having managed with three tools in the Front 4 way, and another three in my home made 4 way Back Toolpost, for ten years, maybe the need is not really that great, and a spend circa £250 is a bit off putting.

(I made a tool height setting gauge to speed/ease setting Front and rear mounted tools to centreline)

Also, my shop being compact/congested (take your choice) where would I store the spare holders?

The shelf above/behind the lathe already carries Drill Chucks, Running Centre, Faceplate, Catch Plate Steadies, and Collet Chucks, so no room there. And don't even think about the storage spaces beneath - already fully used!

So votes For, and who Against please.

Howard

For a table giving details of Morse, Jarno and Brown and Sharp Tapers look at

littlemachineshop.co./Reference/Tapers.php.

The suggestion to put a bar in the 3 Jaw chuck and turn a centre is a good one. The centre will be on the REAL centre line if the headstock. If it is marked in line with say, Jaw 1, before removal, it can be replaced with reasonable accuracy. Or clock the bar in a 4 Jaw as accurately as possible, turn the centre, and then reclock to centre it with a DTI on all subsequent uses.

BUT before aligning the Tailstock, do make sure that there is no twist in the bed, otherwise the Tailstock will only be accurately aligned at one point on the bed, and you will be unlikely to be able to turn parallel over any length.

To check and adjust, either :

1) Use a sensitive spirit level on the cross slide - assuming a flat machined top surface, and check at Headstock and Tailstock ends.

Or 2) Lay the level on the ways, (use parallels if your lathe has Vee/Flat ways, and work off the flat ways for the Saddle and Tailstock)

Be aware of the danger of wear on the bed affecting the results, so use the extreme ends, which, not being traversed by Saddle or Tailstock, are less likely to be worn, if possible!

The level does not have to be ABSOLUTELY level, the essential thing is adjust/shim the lathe feet, so that the same reading is obtained at both ends, on unworn areas of the ways, to ensure that there is no, or absolutely minimal, twist in the bed.

3) The Operator Manual for the Myford 7 Series tells how to check for, and to remove twist by machining and measuring a test piece held in the chuck.

Which method you use depends on the configuration of your lathe, and the facilities that you possess, or can borrow.

Howard

It was not unusual to "buy in" an engine from another, usually larger, manufacturer.

Morris used Hotchkiss engines, for instance.

In the late Thirties, the British Salmson was a bit of an All Spare Parts, using a Salmson engine, Morris gearbox, and Ford wheels, so threads could be a real mixture.

That sort of thing persisted even in the sixties, carrying over parts from earlier models.

The Leyland Leopard bus/coach chassis was to Unified standards, but the Leyland 0600 and 0680 engines fitted, and their gearboxes, and axles were to the previous BSF/BSW standards. Brake adjusters from the BSF/BSW standard Tiger Cubs were interchangeable, so onc avehicle was in fleet service, one side could be A.F, and BSF size hexagon on the other!

And when, in the late 60s, the Overhead Cam 500 Series engine to metric standards was fitted, some hardware could be to a third standard. It just depended on which "era" the part the part had been designed.

So don't be too surprised by what you find!

The engine is French, so metric threads could reasonably be expected.

To my mind, unlikely to be 9/16 SAE, which is an American standard. Did SAE standards even exist that long ago?

However, as already said, in the early days like the twenties, standards probably were not so rigorously followed, in the motor industry, so it is likely that it could be a bit of a special.

It is not a pipe thread is it?

The Austin designed 803cc A Series engine used in the A30 and the first OHV Morris Minors, during the 50s used 1/8 BSP ball ended screws, with a 7/16A/F locknut , as the adjusting thread on the Rocker levers, and this probably carried over onto the Mini.

1/4 BSP is Whit form, 0.518 (13.157mm) OD and is 19tpi, which might be a possibility.

The French STILL use BSP threads for plumbing fittings such as Taps (Faucets) , referring to them as "Half Gas" , or whatever, size fittings.

Howard

You have a useful piece of kit there.

The black rectangular bar, (with the 1/4 or 5/16" spindle attached) can be fitted onto a Height Gauge, for use on a Surface Plate or table. It can also be clamped (carefully, and preferably protected on both dises) in a toolpost on the lathe.

The clamp will allow it to be fitted in a variety of places, but as has already been said, not to Surface plate or table.

The DTI can be used as a normal Plunger Clock, or as others have said, to check run out, (or position) of bores, using the pivoting accessory.

Quite versatile, you will find it very useful as time goes on.

Well Done for a good find!

Howard

If Becky can find (Borrow? But keep swarf out of it!) a Ball Race (or even the inner track of a Taper Roller Bearing), of the right size, in good, or preferably new, condition, this would probably be a splendid spacer?

Howard

Hi Fellas!

A while ago, I had to make a one off 1 Mod 15 tooth gear, but had only a 1.25 Mod cutter.

After completely messing up one blank, I reduced the depth of cut shown on the cutter by a factor of 1:1.25, and a useable gear resulted.

This is theoretically wrong, but it sufficed for that particular application.

So, if you can get a 14.5 PA cutter, even if it is 1.25 MOD, you MAY be able to bodge in a similar way.

"Where needs must" and all that!

Howard

Hi Becky!

For what my advice is worth, try the following.

Before fitting any Chuck or faceplate, or anything else, to the Mandrel, always ensure that the thread and register are clean. Don't forget the thread in the Chuck or backplate, also!

An old toothbrush is handy for cleaning threads, (or Taps) in this way.

1) Screw the Faceplate onto the Mandel, (it may be worth marking, after skimming, the Faceplate and the Mandrel - if possible, so that in the future you screw the Faceplate onto the same point each time), and then lightly skim the face of the plate until it cleans up all over.

2) Having done that, then lightly skim the Outer Diameter of the Faceplate, until that just cleans up all round.

Those operations should cure your Faceplate problems.

If the three jaw, or four jaw chucks wobble, I suggest that you remove the Backplate. If the backplate has been removed previously, there ought to be pop marks on Chuck Body and Backplate that are in alignment.

Are there? Or if they are away from each other, remove the Backplate, clean the plate and the register in the chuck body, and refit it with the marks aligned, and check if it still runs out or wobbles when fitted on to the Mandrel.

If the Chuck Body and Backplate have not been marked, BEFORE separating, pop mark each one with the marks close together, so that when refitting, they go back in the same relative position.

Screw the Backplate on to the Mandrel and again very lightly skim the face until it cleans up all over.

Do not skim the Outer Diameter, or you will lose the concentricity of the chuck.

Remove it from the Mandrel, wash or wipe it clean, and refit to the cleaned register in the Chuck Body.

Incidentally, do not expect a workpiece held in a three jaw chuck to run absolutely concentric. A good chuck will be within 0.005 inch, a bad/worn one may be anything up to 0.030 inch or more.

If there are diameters or bores that have to be concentric, machine them at the same time, without moving the workpiece.

If this is not possible, then for the second operation(s) the piece needs to be held in the four jaw chuck and the original diameter clocked to run true before starting to machine the later ones.

Sorry if this latter bit is what you already know, and do, not trying to teach you, or anyone else, to suck eggs!

Good Luck!

Howard

Since the pitch is 3mm, the thread is certainly going to be metric.

No one in their right mind, in volume manufacturing, is going to cut a 7/8 inch by 3mm pitch ACME thread, are they?

The worrying thing is that the OD varies from 22.1 to 22.25, which would be oversize for a 22mm, and grossly undersize for a 24mm.

Suggestion

The backlash is because the nut is a loose fit on the leadscrew, so why not experiment cutting a nut to 22 x3, and see how it feels? Adjust the O.D. until you are happy with the feel in steel (lubricated - you don't want any pick ups to damage the leadscrew) When you are happy with the fit and feel, for each leadscrew, then make the final version out of your chosen material, (Cast Iron, Brass, Bronze, Phosphor Bronze etc).

It goes without saying to lubricate the screw and new nut well before final assembly.

If you want to minimise backlash, split the nut crossways, and fit a screw to allow you to compress or expand the nut longitudinally to reduce backlash. In future you could use this to compensate for wear.

Howard

Like Mick Dobson, I was involved with I.C. engine manufacture and development for almost all my working life before retiring.

I would be very doubtful if you could find an adhesive/sealant that would withstand the temperatures to which the valves and seats are subjected at full speed, full load, To give you an idea of the temperatures, for many years, valves have used sodium cooled valve stems, and the valve seats are made of materials that cause experienced Methods and Production Engineers heartache to machine.

Despite the exhaust temperature being upwards of 700 C, the valve and seat temperatures will, even instantaneously be well above coolant temperature. And Air Cooled heads tend to run hotter than liquid cooled.

Believe me, if a valve seat comes loose, you will be very likely to find the only repair being to jack up the rocker cover and bolt a new engine under it!

Fit the valve seats by the "Heat and Freeze" technique (In industry the seats are frozen in liquid air or nitrogen before fitting and then pressed in). This assumes that the parent metal is of sufficient thickness to withstand the stresses from the interference.

If possible have the outer edge of the seat inserts overlap the cylinder wall, so that they can't fall into the cylinder. I have seen even the valve inserts (steel in an alloy head) staked, or even screwed in, come loose on air compressors, which run at much lower temperatures, and then they are not a pretty sight.

You are unlikely to run the engine for 50 hours non stop at full load rated speed, but a model aircraft, or powerboat, engine will run long enough to total itself if the seats come loose.

Months to machine and build, but a second to become scrap metal if anything goes badly wrong, so do be careful!

Howard

Four of us went, on Saturday. On a Group ticket, it cost us £8.25 each from Peterborough. (Free shuttle bus from/to A.P. rly station

With tickets booked on line, we just walked straight in.

Something to bear in mind for the future.

Looking forward to Harrogate, but there is going to be show at Springfields in Spalding 26/27 April, so hope to see what thats like.

Howard

If it is to reduce the height, you could rough it out with an angle grinder, and then get the local machine shop to finish to size on a surface grinder.

Howard

Someone once said to me, "You can do small work in a big lathe, but you can't do big work in a small lathe".

So my advice would be to buy machines that seem a bit larger than your immediate need.

Workshops can always be bigger, although the larger the shop the more problem it is keeping it warm, or cool, depending upon ambient temperatures.

My workshop is 6 feet 9 inches by 10 feet 9 inches, externally, with 19mm outer cladding on 50mm frame work, with glassfibre insulation between the 12mm ply inner cladding. The roof is two layers of felt on 12mm ply on 50mm framing, with glassfibre between and 12mm ply inner cladding. The floor is 18mm ply supported on five off, 8 inch by two inch bearers on concrete slabs.

Heating is by a thermostatically controlled 2 Kw fan heater, on the floor under the fitting bench. ventilation is by a six inch fan set into the back wall, with fixed vents at floor level. The intake is cowled to prevent ingress of rain. You may need something different for your climate.

The door is at one end, offset to match the 18 inch wide fitting bench. The lathe is on a 30 inch wide bench on the other side of the narrow aisle, beyond a small bench carrying the surface plate, with a tool cabinet containing measuring equipment, stored on top of it.

All benches are steel of 37mm angle iron or box section construction

The Mill/Drill is on a bench across the end of the shop, placed so that at full travel, the table JUST clears the wall on the fitting bench side.

The pent roof is high enough to allow the drawbar to be removed from the Mill/Drill, and for the belt cover to be opened with the head at the top of the column.

Against the wall, the bench carries cabinets with small drawers containing milling cutters, hardware etc.

Shelves above the benches are used for storage, as is the space beneath the benches.

There are no windows, partly for security, and because the shelves, and their loads, would block them anyway.

For security, the door is a firedoor, fitted with a 6 lever lock, and hingebolts. You may not need to be so careful, but model engineer's equipment and output is prone to theft in U.K., and no doubt, elsewhere in the world.

Lighting is by two 85W fluorescent fitting end to end on the ceiling, with an LED worklight over the vice, and each side of the Mill/Drill, with a halogen lamp on the lathe.

Because there are no windows, there is an emergency light (11W fluorescent) mounted high on the inner end wall which cuts in if the mains power fails. Power is supplied from the house via a RCD, to the lights, and to eleven metalclad double sockets fed from a ring main.

Depending upon your viewpoint the shop is either "compact" or "congested". With very little free bench space, increasingly I think the latter, but the Director Gardening would not allow the Patio Wall, or the Bay tree to be moved!!

Hope that this gives some food for thought or ideas, even if only a warning not fall into the same trap!

Howard

Being a "faster" taper, R8 releases more easily than Morse. (The International tapers for Industrial Milling machines are even "faster", but the drive to the cutter is via dogs on the holder, not the taper).

2 MT is a bit small, unless you have a small Mill.

So here are my experiences, if they are any help.

My Mill/Drill is 3MT, which matches the Tailstock on my Lathe, so allowing tool holders/drill chucks to be interchanged, if so wished.

To avoid belabouring the bearings in the Mill head, I turned down some of the lower part of the spindle pulley retaining nut, and made an "extractor" which, when needed, is fitted by two 1/4 BSF setscrews, to a plate surrounding the lower part of the nut, with a 1/4 BSF forcing screw to act on the slightly slackened drawbar.

If the forcing screw does not "break" the taper, a light tap with a mallet then does.

For tooling with a tang, the usual taper drift is used to release it.

Having bought a 2MT ER25 collet holder for my previous Myford ML7, this is now used with a 2 -3 hollow adaptor in the Mill/Drill.

If needed for the 2MT Rotary Table, a home made separator with a 1/2 UNF forcing screw removes the adaptor.

In the lathe, ER 25 and ER32 collet chucks are on home made backplates, which allow work to pass through the chuck, and into the mandrel bore.

With regard to tightening torques, I could not apply 100 lb ft to any of the ER collet nuts with my chuck spanners, but have not had plain shank end mills, up to 20mm dia. (16mm shank) work their way out.

But it is surprising just how tight the nut has to be to hold a tap firmly, in my home made ER25 Tailstock sliding Tap Holder on the lathe.

(Yes, I did lap the bore with emery tape around a collet, to get a good fit!)

But a useful safety device which probably avoids broken Taps!

The choice is yours!

Howard

There is not much scrap in the world, only when it is too small to grip to carry out further operations, or when already in small curls of swarf. (although isn't that what those stainless steel scourers are?)

Somewhere there is a plastic bottle containing all the screws removed from old VHS cassettes. There MUST be a use for them sometime.

After ten years of retirement am now reduced to buying material sometimes! Boy; do I miss the scrapyard at work!

ER collets are GOOD!

ER32 seems a bit big for a machine with a MT2 quill. You could find the nut getting in the way sometimes, and as Roderick says, it may be difficult to grip really small drill or cutters.

Years ago, when I had a ML7, and a Rodney milling attachment, I bought ER25, from Chronos, and have never regretted it. Since buying a Mill Drill, I use the ER25 collet holder in a 2 -3MT sleeve.

Although I now have collet chucks for the larger lathe, ex Warco, in ER25 and ER32 (I have just 4 collets to extend from the 16mm of ER25 to 20mm; but they are rarely used).

Also made up square and hexagon holders for ER25 and ER32, to use in the vice on the Mill/Drill.

I have made ER25 holders for Taps on a Tailstock Sliding Die Holder mandrel, and for a Floating Holder for Hand Reamers. (For machine reamers made up soft ER32 collets to take 1, 2 and 3MT shanks. Did not change the Topslide set over between boring for the collets, and turning the OD of the collets. Slitting the collets was interesting!)

For drill grinding on my Worden, I made up an ER20 holder. The 1 -13mm collets were expensive, or seemed so!

Making your own holders is a useful exercise in screwcutting.

For all these pieces, I bought the closing nuts and spanners (and the ER20 collets) from Arc Euro Trade.

Possible suppliers (take your choice) Arc Euro Trade, Chronos, Warco, Chester, and others.

Howard

No it wasn't the correct cutter for 15T, (a No.7) and I knew that using a No.2 was theoretically wrong.

The main thing is that although the gear tooth form may well be wrong, if for that reason only, it does the job.

(Very little backlash between the rack and new pinion)

If you had seen some of the other parts that I had to remake, (supposedly central tappings at an angle to the axis on turned parts!) you would wonder how the thing ever worked at all. The gear exploded because it was a very loose fitting sinter on a shaft with a flat, (which acted as a cam and forced the gear apart. The shaft even had an un needed thread on it - ex a M8 bolt perhaps?). It was fun brushing the sawdust out of the pairs of teeth. By the time it reached me, the gear was in five pieces, from which the OD and number of teeth had to found.

I was doubtful that you could really compensate in this way; if it were, every man his dog would be doing it!

So, it was really the wrong thing to do; but where needs must and so on.

But it put son in law back in action again with his bandsaw, which was the object of the exercise.

Wasn't it De Bouton, ( or perhaps Leon Bollee) who said "It's rough, but it works" of the gearbox on his car?

Howard

I needed to make a replacement for a failed gear, from a Chinese wood bandsaw. When I put together the jigsaw of loose teeth , the gear appeared to be have 15teeth, but the OD was not correct for 1Mod, or for 1.25 Mod.

For starters, having only one 1.25 Mod cutter, I made a 1.25Mod, 15T gear. It was too big, so turned down the blank to the size for a 1Mod, and recut the teeth, (there was a witness of the bottom of the teeth.

Disaster! the teeth were were like a church steeple, cutting a couple; before starting again. This time I used a depth of cut which was the 1.25Mod depth of cut reduced by a factor of 1.25 to 1. Although cut with theoretically the wrong cutter, both in terms of Module and number of teeth, the resulting gear worked well.

Not being knowledgeable about gear cutting, especially where Module gears are concerned, was it correct to reduce the depth of cut by the 1.25:1 factor, to try to allow for the 1.25 cutter being used on a 1 Mod blank?

Any advice would be welcome; not that I wish to make a habit of doing things this way!

Howard

Another belated response.

Two cranks at 90 degrees, will, if put into static balance, should each be in Primary balance.

The fact that the cranks are at 90 degrees, will mean that they are also in Secondary balance, although, because the cranks are not in the same longitudinal plane there will be some couple acting on the engine. This will give it a tendency to squirm around a vertical axis.

What will determine how smooth, (in terms of vibration) the engine is when running is the proportion of Reciprocating mass that is balanced as compared to Rotating mass. You can spend a long time experimenting to optimise that!

The mass of the flywheel will have no effect on vibration (unless the flywheel is out of balance!). What it will improve with increasing mass is the smoothness of angular rotation speed. Whilst a heavy flywheel will minimise the speed variation at the flywheel end, it is likely to increase the speed fluctuation at the free end (Torsional vibration) This is because the heavy flywheel tends to act as fixed point about which the flywheel can vibrate in torsion.

In a two cylinder engine, unless the scantlings of the shaft are such that the pins and journals are thin and long, it is not likely to be a problem.

If you were making a high power eight cylinder engine, with nine main bearings, it might be another story!

Lanchester Harmonic Balancers are most often applied to four cylinder engines, although the trend towards three cylinder car engines makes their use more likely. The balance shafts, with their balance weights have to be timed to the crankshaft and each other, and geared to run at twice engine speed. If the balance shafts are not accurately timed to the crankshaft, the engine could turn out to be coarser than without them!

The function is that the secondary out of balance forces from the balancer shafts oppose the secondary forces of the reciprocating and rotating masses and so, to an extent, cancel them out.

On a twin cylinder steam engine, I have never heard of their use (but there may be examples), and are probably not needed.