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Member postings for Nigel B

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

Thread: Saddle play when direction of cut is changed in my ML7
07/09/2017 09:19:37

Presumably regular gib strip in front side of saddle need to be shaved a bit to widen gap on the back. Probably unused shear will need scraping to provide better bearing surface. What do you think about it?

It didn't on either count when I did mine. There was enough clearance in the apron screws to get the half nuts engaging correctly as well (slacken apron screws, engage halfnuts as close to the end of the screw as possible, tighten apron screws).

Rather you than me

Indeed. It took me two months of lunchtime sessions where I last worked to do the top of a Super 7 bed that had around 0.008" wear. Milled the vertical faces on a large Zayer bed mill as a "test cut" after it was rebuilt & retrofitted after a fire.

Nigel B

Thread: How was it done before CNC
07/09/2017 08:15:56

These were used from the 1950's I believe.

Keller electric copy mills were used before that during WW2 to make aircraft propeller blades IIRC. The Kellers used AC motors running continuously & electric clutches controlled by contacts in the stylus assembly for the axis feeds. The stylus traced across a template, with the clutches being controlled to keep the pressure on the stylus in constant contact. With multiple milling spindles, several parts came off for each cycle.

I wired the last Hayes hydraulic copy mill to be built, sometime around late 1982 IIRC. I had been seconded to Hayes (Meanwood, Leeds) for a couple of weeks while at Boxfords (both part of the Brooke Tool Group at the time) when one of their electricians was off ill. At that time they were rebuilding copy mills that made the small compressor blades for jet engines (IIRC the machines were for Pratt & Whitney Canada) 4 at a time. One of the first service visits I made while at Broadbents (which became Broadbent Hayes) was to a Hayes copy mill at a forging company in Wednesbury (I drew the short straw on that one and the wiring of the last machine because I had seen one before !), so those machines were still being made and used into the '80s, long after CNC had become more affordable.

Other components were made with machines that ran simple cycles to limit switches & there were also plugboard controlled versions. At the time I was at Boxford (Sept '80 - August '81) they only had 2 CNC machining centres but had several "point to point" simple cycle milling machines. Multiple drilling operations were carried out with "tumble boxes" (machining fixtures with drill bushes) on gang drills.

Much more part handling, swapping parts from machine to machine with each machine set up for one operation. A bed casting for a South Bend style Boxford (for example) started off as a rough casting machined falt top & bottom on a planer, went to a "Duplex" mill for the milling of the top bed formation (all vees, flats & sides) at one pass using a gang milling cutter, moved to the Varnamo point-to-point section for the undersides of the vees & rack mounting faces milling, rack mounting & leadscrew bracket holes drilling etc. A headstock casting had the vee formation gang milled, then was mounted on a fixture using the vees on a CNC horizontal machining centre with a rotary table, where all subsequent maching was done at the one set-up - much less handling required.

If you want to make a great many parts, all the same, then transfer machines probably still rule. Hattersely Valves in Halifax used rotary transfer machines (Diedesheim or Vogel IIRC) to make brass valve bodies. The parts were held on a vertical axis platter that indexed through 8 or 10 postions. At each position was a machining head. The operator took a finished part from the platter & loaded a blank in it's place - on starting the cycle, the platter indexed one station & all heads completed their cycle. The part progressed around all the maching stations in order, so every cycle saw a blank loaded & a finished part removed. A bit challenging to set initially & used a lot of specially ground form tools, but once set & running the parts came out very quickly.

Nigel B

Thread: Making a new mill over arm, accurately measuring long distances?
06/09/2017 15:09:12

I want to be chasing 0.01mm. Considering getting a 300mm caliper for £20 off fleabay so that I can at least get an approximation.

You may get an approximation with a £20 300mm caliper, but you won't be chasing 0.01mm with it !

Nigel B

Thread: Rebuilding an ML7
06/09/2017 12:16:49

Now this leads me to the suspicion that the headstock isn't aligned to the lathe axis? True of False?

I would suggest false. The shims set the bearing clearance, not the alignment of the spindle axis with the bed guide faces.

Now here is the rub. This same test is used to see if the bed is straight. so how do you tell the difference between the two?

You dont. Now you can see why machine tool builders use a precision level (or other means, such as a laser interferometer) to set the bed "level " (i.e. without twist or bow) first. You now have a reference to check the headstock alignment using a test bar in the spindle (dial gauge on the saddle - check in both vertical & horizontal planes).

If there were cheap & easy shortcuts to building machine tools, be assured the machine tool builders would have found them by now - the Yorkshire based companies certainly would !

Nigel B

Thread: Help with this milling tool holder
05/09/2017 21:27:30

Cutwel have ER collet chucks in SK30

**LINK**

If I ever make room in the garage to get my ex-industrial Triac out of storage, I'll be looking for 30 taper tooling as well.

Nigel B

Thread: Pinning topslide on ML7/Super 7
05/09/2017 08:40:06

Be wary of overtightening the standard Super 7 arrangement. The cross slide is weak at the point where the clamp holes intersect the top slide bore. On the 2 Super 7s I have had, both cross slides were bent at that point & required regrinding.

I only apply a slight nip to the clamp screws after regringing the cross slide to try & prevent a repeat & have not had an issue with the top slide moving under load.

It has been a while since I had mine apart, but I seem to recall that the ends of the clamp pads are cut differently - the use of one photo for two part listings is probably laziness, as the original Super 7 parts list has them as different part numbers and describes them as handed.

Nigel B

Thread: Pros and cons of ac motorcycle lighting.
05/09/2017 08:06:43

Some versions of the Indian made Royal Enfield Bullet had a split AC-DC electrical circuit. There was the usual rectifier/regulator arrangement for the DC circuit (everything except the lights) from one set of alternator windings & an extra lighting circuit alternator winding that had an external voltage limiter.

I don't know for certain why this was done, as earlier versions of the same bike had an all DC arrangement - I have had one of each & there was no noticable difference in lighting performance. The all DC bike had a bit of an appetite for rectifier/regulator modules, though, so maybe the change was done to reduce the load on the DC circuit to improve reliability ? This was at the expense of an added winding + another voltage limiter module so, potentially, more bits to wrong !

If the headlight bulb blows, the tail lamp will generally follow almost instantly. This is because the system is trying to force the same current through it that the headlight took.

Not so much extra current, as that the voltage is regulated by the load - if one bulb fails, the load reduces & the voltage rises. At the higher voltage the remaining bulb takes more current, runs much hotter & fails. This also happens with bicycle dynamo lighting arrangements & Shimano make a small voltage limiting module to prevent total loss of lights should one bulb fail. These are only rated at 3W (typical bicycle dynamo output), though, so not suitable for motorcycle use. IIRC use of these modules is a requirement of the German Traffic Regulations for bicycles

I'm not au courant with modern bikes, but I suspect most of the larger ones would still be using this sort of system.

The regulated field alternators have pretty well disappeared now - 3 phase permanent magnet alternators have been the norm for the last 20 years or so. Look at most modern bikes & you will find a large finned module placed in the breeze - this is the rectifier/regulator module & they "regulate" much like the old Zener by shorting the windings to ground. BMW may still use the wound rotor type (my wife's R65LS has one, but that is over 30 years old !), but I have not had a recent BMW so can't say for certain. Some older Moto Guzzis used the same Bosch unit as BMW did at the time (late '70s early '80s), but my Mille GT bought new in 1989 had a permanent magnet type.

Nigel B

Thread: Tow bar wiring loom
05/09/2017 07:40:25

Hyundai give a 7 year warrantee with their cars

In the UK, Hyundai have a 5 year unlimited mileage warranty - Kia have a 7 year 100,000 mile arrangement (got both a Kia & a Hyundai on the drive).

The new Mk8 Transit does have a plug-in point to accept a towbar wiring loom. The towbar for my motorhome cost £700 installed earlier this year - a large part of the increase from £350 for my last one was the requirement for the towbar braketry to be Type Approved now, so instead fo a bespoke bracket made to suit the van a modular "kit" towbar that has been Type Approved in all it's various configurations has to be used. The wiring loom used on mine was aftermarket, designed to plug in to the Ford main loom (and just to make life more interesting, there are two different types of electrics used on the new Transit) & came with a 7 pin socket. My towbar mounted cycle carrier has 13 pin electrics, but was supplied with a 13-7 pin adapter.

Nigel B

Thread: Is 3/32" round tool steel now unobtainable?
31/08/2017 15:32:38

**LINK**

Any good ?

Thread: Something exciting on its way...
31/08/2017 09:09:52

So............

.......... how will you be levelling the new toy ?

Nigel B

Thread: Mega Mill in Classifieds
30/08/2017 17:51:51

Dont see a Mega mill advertised in classified ads......

First item in the "CNC" section.

Thread: Chinese Electric Cars
23/08/2017 08:58:32

P.S talking of detail; I presume that "power your home" should read "power you home"

Not necessarily - something pubilshed recently by, IIRC, National Grid was suggesting that the batteries of electric cars connected to the grid could be used to supply the grid at periods of high demand & then recharged (as the owner was expecting when they connected it in the first place) when there was excess generation capacity.

NDIYs suggestion of charging your car FOC at a public charging point & connecting the fully charged car to your house to provide power for the house was, I suspect, rather tongue-in-cheek.

Nigel B

Thread: Level lathe set up
22/08/2017 12:34:56

Sure,but do they have wire mesh inside?

The type made by Marshalls don't have any steel reinforcement, they are just hydraulically pressed. Drilling holes can still be interesting, as pressed concrete blocks are very dense (my house is built from Marshalls Heritage blocks).

Bolting to a granite or concrete block is not dissimilar to the industrial practice of casting a substantial concrete foundation, which some machines need more than others !

Nigel B

Thread: Chinese Electric Cars
21/08/2017 15:51:08

Just looked at the Leaf. Wow it's expensive.

Even more so when you consider the initial depreciation if you buy new - my brother bought an ex-demo top of the range Leaf (with outright purchase of the bigger battery & the "faster" charger) around a year ago. IIRC the car was under 6 months old with 4000 miles covered at the time & it cost him £14K. Again IIRC, "list" was something like double that !

A year and 9000 miles further on & he thinks it's wonderful. He uses it for work & has covered up to 300 miles in a day - range is up to 135 miles on a charge & the motorway services fast chargers put in an over 80% charge in under 30 minutes for £6. The built-in satnav shows suitable charging points for longer journeys. Last time we spoke he reckoned the 9000 miles had cost him directly under £60 (by using FOC charging wherever possible).

As my daily commute is 92 miles round trip, only Teslas have a "workable" range for me to avoid "range anxiety" & I can't afford one of those without a lottery win.

Nigel B

Thread: Would you buy a second hand laptop computer ?
18/08/2017 13:20:10

When my wife's Medion died, we looked into various options & ended up with a second hand Dell from a local independant computer shop. The going rate at the time for a new i3 HP with a 768 display was £399 - the Dell was an i5 with a 1080 display for £50 less. Both came with W10 Home & 12 months warranty. The used machine has been problem free for the last 12 months. IIRC the shop said that the used Dells he sold came direct from Dell.

At work my workstation is a used HP that came from Pyramid Computers. W7 Pro & problem free for the last 3 years. IIRC it was £200-ish & came next day.

Seem to be able to get better performance for less money buying an ex-commercial machine & I will look in that direction first next time I need one.

Nigel B

Thread: Level lathe set up
18/08/2017 12:39:43

Surely the bed will be flat if no external load is applied?

Maybe, maybe not. That could depend, for example, on whether the bed casting was properly stress relieved at the point of manufacture - it may have been naturally straight at the time it was built & gradually move over time as the stresses worked themselves out over time. In that case, it would need "un-twisting" when you installed it later.

I used to work for a company that rebuilt & updated CNC machine tools & cannot recall any vertical borer, large lathe or milling machine installation that would sit naturally "true" - all required bolting to the floor (or other foundation, depending on the sub-soil & floor concrete depth) & carefull tweaking of the levelling bolts to achieve the required "levels". In "our" factory, which was purpose built, the floor was 600mm thick concrete & the machines being worked upon were bolted down with chemically anchored high tensile studding.

It may well be that a small machine, like a mini-lathe, would sit naturally "true" if the casting was properly stress relieved before maching, but I suspect that anything bigger would be prone to movement - castings are a lot more flexible in practice than you might think.

Boxford used to stress relieve the South Bend style beds naturally over many months. They sat stacked on pallets in the yard & were hosed down daily if it wasn't raining. After 3 months or so, the castings were shot blasted with steel slag, "topped & tailed" on a planer & put outside for another 3 months. Then another shotblast, filled & painted before final machining. The later geared head beds came in supposedly stress relieved from the foundry - they were found to "move" during heat treatment (induction hardening of the slideways) & after a lot of trials & jig was used to bend the bed hollow before it was hardened. After hardening, the tension was released, then re-applied at a lower torque setting before grinding - the finish ground bed then came off straight.

On the cabinet mounted lathes, the beds were mounted onto a bed of Isopon polyester paste on the base fabrication & set true with a level. The excess paste that exuded as the bed was pulled down was trimmed off before it hardened.

Nigel B

17/08/2017 10:42:17

No need to be like that Nigel.

Apologies for any offence, Russell - my remark was intended to be light-hearted & I forgot to add the "smiley".

The object of "levelling" the lathe is to return it to the state that the manufacturer built the machine in when they documented that it met the accuracy standards. This will then allow the user to confirm (or otherwise) the manufacturer's documented readings. I do not believe that the "Method" (be it Rollie's dads or Rolly's dads) will do that. That does not make it an unreasonable method of checking headstock alignment if a suitable test bar in not available, but after the bed has been set "level" .How does this "Method" differentiate between a twisted bed and a mis-aligned headstock ? There is more to using a lathe than just turning parallel - will twisting the bed to get parallel turning when the headstock is mis-aligned cause problems with the tailstock alignment at different distances from the chuck that put drills off centre, for example ?

Is £40 unreasonable for a piece of precision test equipment ? Is it really a lot in terms of the cost of the lathe, the tooling require to be able to use the lathe & the other measuring equipment to check the output from the lathe ? As to how often it is used, that depends on how often you wish to use it & that will depend on how often the machine moves out of "level". One machine I worked on stated in the manual that the "levels" were to be checked monthly after installation until there was no change between two consecutive checks, then the checks were to be moved out to 6 monthly.

Nigel B

16/08/2017 21:35:09

You lot are slacking - 16 posts in before "Rolly's Dad's Method" came up !

Buy or borrow a proper level & do it right.

£0.02

Nigel B

Thread: Imperial tee bolts for Myford?
16/08/2017 19:23:59

It's more difficult to get non-metric fasteners these days

Quite easy to get BSW, BSF, UNC & UNF cap screws, grub screws, set screws & bolts from Cromwell Tools in a wide range of sizes. Delivery has always been ex-stock (same as metric) when I have had cause to have to get any.

Don't recall seeing Imperial Myford tee nuts in the catalogue, though.

Nigel B

Thread: Level lathe set up
16/08/2017 19:17:06

There are slant bed lathe which are definitely at an angle front to back but probably still levelish lengthwise.

Slant bed lathes are leveled front-to-back using a fixture held in the turret that puts the level errr.... level.

Sometimes this is provided with the machine as part of the original equipment, sometimes the installation technician brings the factory tool along with him (and takes it away again) or, in my case, you make one when you get a second hand machine.

When (reasonable quality) lathes are manufactured, the alignments are set with the bed set in a known condition. Setting the bed back to that known condition on installation should, therefore, bring all the other alignments back to the values shown on the inspection record. In the greater (industrial) scheme of things, a precision level is cheap & easy to use, so using one to set the bed level is easy for both machine builder & end user to get to a known condition.

A 0.05mm/metre level can be obtained from Ebay from £40-ish (Item 272295866038 for example), which isn't a great deal for a precision measuring device.

Doubtless there will be other posts along shortly extolling the virtues of "Rollies Dad's Method" (whoever Rollie was ?) to set up a lathe & decrying the use of a precision level in the home workshop - to each their own !

Nigel B

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