Here is a list of all the postings mgnbuk has made in our forums. Click on a thread name to jump to the thread.
|Thread: Micro Bearing Question|
How about ceramic bearings ? A quick Google for a spec on a ZrO2 696 bearing from one manufacturer gave an operating temparature of up to 250 C and 12000 rpm when oil lubricated - other makes may give different specs. & alternative lubrication regimes may help increase the operating speed.
|Thread: Embarking on a metal planer/shaper design+build|
This publicity / education film by Waldrich form, at a guess, the 1950s gives a good look at the machines & the operation of their hydraulic feed system. **LINK**
The film commentary is in German, but it isn't hard to work out what is going on if you don't know any / much German.
Capable, versatile machines that have been, largely, lost from UK workshops, with nothing to replace them in many cases.
Is the "cubic metre" the total envelope of the finished machine, or the workpiece volume ?
"It would be brilliant if we could see some metal planers and shapers in action; "
You are about 20 years too late to see that easily - and they were getting thin on the ground then
"but remain in use in industry."
Barely. This one is currently for sale local to me. **LINK**
This is one of the last I know of - 2 of the 3 the others I used to have work done on have been scrapped over the last 10 years or so & I would not be suprised if it failed to find a buyer & was scrapped also. Even assuming it got a bid at the start price, it would most likely cost at least as much again to get it dismantled, moved, a foundation put in & re-installed. The Waldrich linked to was actually the smaller of the two planers at that company, so I guess that the larger Craven has already been scrapped. I dismantled a Swift Summerskill planer for scrap where I work now about 5 years ago - it was worth more as scrap than it would have sold for intact. There was nothing wrong with it & I felt guitly about having to kill it, but we needed the space for another machine that would make money. Planer tables fitted with legs & used as marking out or assembly tables come up in auctions quite regularly - every one a dead machine. At one time they were sent out to India , but that market largely disappeared when the indian Goverment put large import tariffs on used machinery to encourage Indian industry to invest in new machines rather than buying obsolete used ones.
I wonder why the lecturer set this task, as universities have been teaching that planers & shapers are obsolete for at least 25 years - I had to work with a placement year engineering student over the acceptance of a rebuilt machine that long ago & he brought in one of his course books on machine tool technology that dismissed planers in half a page, with a line drawing & one paragraph. Maybe beacuse the students would be unlikely to come across one in real life & have to work out how they worked from scratch ?
Edited By Nigel B on 12/10/2017 20:08:25
|Thread: Denford Triac Mill|
Sounds like your mill has a Coventry Easy Change toolholder
MSC Industrial Supply carry these **LINK**
Make sure you are sitting down before looking at the prices !
I believe all Triacs were fitted with steppers in std form
Not all of them.
I have an ex-industrial Triac that is different to those shown above - it is on a twin pedestal base, with a removable swarf bin between the legs, with the gas strut balanced, full width lift up front guard. The electrical cabinet is full width across the rear on the pedestals. Control system was a Heidenhain TNC355 (operator station mounted on a swinging arm from the base), with brushless servo drives (can't recall the make, but not "main stream" to all axes. Spinde is BT30 with an Erickson locknut & no ATC. Spindle drive is a 2.2Kw squirrel cage motor directly connected to the spindle with a polyvee belt - it originally had an IMO inverter drive. The machine was bought in to scrap for the electronic parts where I used to work & I bought the carcass for £100.
The Fanuc Triac shown above would also have had servo drives - type dependant upon the exact model of Fanuc 0M fitted (the "A" models were analogue interface, "B" & " C" models were all digital & could only use Fanuc's own brushelss servos).
I really should make room in the garage to get it out of storage - it's only been there 11 years now ! I have the stepper motors, stepper drives, PC break-out board & an inverter already bought in to get it up & running again. I planned to remove the rear mounted cabinet to save floor space & cut out the side of one of the pedestals to let in a smaller box (also already to hand). Unfortunately the lift-up guard & the swarf bin had already gone out in a skip before I got the OK to buy it.
Have fun with yours,
|Thread: Saddle play when direction of cut is changed in my ML7|
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.
|Thread: How was it done before CNC|
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.
|Thread: Making a new mill over arm, accurately measuring long distances?|
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 !
|Thread: Rebuilding an ML7|
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 !
|Thread: Help with this milling tool holder|
Cutwel have ER collet chucks in SK30
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.
|Thread: Pinning topslide on ML7/Super 7|
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.
|Thread: Pros and cons of ac motorcycle lighting.|
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.
|Thread: Tow bar wiring loom|
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.
|Thread: Is 3/32" round tool steel now unobtainable?|
Any good ?
|Thread: Something exciting on its way...|
.......... how will you be levelling the new toy ?
|Thread: Mega Mill in Classifieds|
Dont see a Mega mill advertised in classified ads......
First item in the "CNC" section.
|Thread: Chinese Electric Cars|
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.
|Thread: Level lathe set up|
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 !
|Thread: Chinese Electric Cars|
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.
|Thread: Would you buy a second hand laptop computer ?|
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.
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