Here is a list of all the postings Clive Foster has made in our forums. Click on a thread name to jump to the thread.
|Thread: Running a 3phase at home|
To extend Stuarts list of possible approaches the Eaton DE-1 series inverters are a sort of halfway house between a full VFD and standard contactor type switchgear and rather easier to install.
Basically they are made to be used as an electronic replacement for ordinary contactors giving soft start and speed setting capablities. They are designed to be used via a simple power on/power off switch so you can easily use the original machine contactors. There is a full blown VFD in the box so you can do full speed control using a calibrated dial but the speed control is more aimed at providing at simple switched speed selection when needed.
A bit cheaper than brand name VFD boxes too.
|Thread: Lathe cabinet/box|
Toggle latches can be got with 90° bases to work round corners, I may still have some somewhere, but they are very inelegant. As I remember it I used some about 30 years ago, shuddered at the looks and said never again.
Can't see any reason why the sort of latch Guy described couldn't be made with the eccentric slotted disk inside driven by an external knob. A horizontal pin suitably spaced up from the base will engage just fine with the slot.
Somehow I ended up with a box of commercial die-cast ones that are, sort of, arranged the reverse of that way with the slot on the outside with a small knob beneath and a separate hooked engager coming down at right angles. Nicely made, well finished and seriously ugly.
If you don't mind making the latch(es) yourself the "Ultimate Box Latch" from Guy Lautards Machinist's Bedside reader is neat and strong. DIY lets you make it the right size for you too. Most box latches are pretty weak.
Basically a circular "dial" about 1/2" thick fitted to the main box with an eccentric locking groove in the back capturing a 1/4" diameter pin projecting from the lid. There is a slot at the thinnest wall part of the groove letting the pin escape at the unlocked position. Guy says his version is based on one shown in Model Engineer, November 22 nd, 1928.
The locking groove being eccentric gives some fitting tolerance. It doesn't really matter if it locks after 1/4 or a turn or 3/8 rd of a turn. Most conventional latches need you to be pretty accurate with positioning the lid and box parts if its not to be loose. The over centre toggle type "ammo box" clips are also good in this respect but less than pretty.
Lots of different ways a latch similar to Guy's can be made. I've seen some similar commercial versions.
Book is out of print so PM me if you want a bit more info.
Edited By Clive Foster on 21/01/2021 13:46:21
|Thread: Benchtop lathe with power cross feed, looking to buy|
A useful sanity check before finalising this sort of purchase is to pick a full on, decent quality, industrial "if I win the lottery" machine as a reference and ask the "what can't it do / what hasn't it got" question of the machines you are considering. Turning the question round from the usual "I want something to do this and ....." sometimes flushes out the red faced "Oops I forgot that".
When shopping we tend to work through a wish list of what we'd like to be able to do and work out acceptable compromises where the depth of pocket won't stretch to match desires.
Which is a good start but sometimes you miss things from the list and sometimes the "better", usually more expensive machine doesn't actually win you anything as the "better" falls into a gap that you won't be using.
For example an 11" swing lathe specifies better than a 10" lathe but if you need to do up to 10" diameter work and would like to be able do some 11" to 12" jobs the 11" machine doesn't actually bring anything to the party. That particular example is something I'm quite familiar with as my small lathe is a 10" swing Smart & Brown 1024 and my big one a Pratt & Whitney Model B 12" x 30" which actually swings almost 14". For reasons I don't pretend to understand I just about never see jobs between 10" and 11" but I see enough over 11" to amply justify having the P&W, although the 1024 is my workhorse.
In practice you are usually balancing one lathe has "this" feature but the other has "that" questions so picking an unobtainium comparator with both onboard can be instructive. For most ME or HW types a Hardinge or my S&B would be sufficiently upmarket to make a good reference but you are already looking for a machine of that size so possibly better to go bigger. I'm partial to Holbrooks but a CVA, modern DSG or Colchester Triumph would be good choices. (Much easier for mills. Bridgeport or Deckel.)
Looking at your prospective purchases from the "can't do / hasn't got" perspective relative to my pair :-
1) The spindle bore is going to be restrictive, my S&B has a 1 3/8" hole which often is less than I'd desire. To save wasting material I often work with a long piece supported in the fixed steady and reduce it job by job.
2) In those sizes I'd rather see an MT3 tailstock than an MT2. But I have a MT3 spindle in my pillar drill so I can share chucks. I have both keyed and keyless chucks anyway but if buying new sharing reduces the cost. What taper is your drill (& mill)?
3) Anything under a true 4"/200 mm useful tailstock travel will be a right PIA when using larger drills. 24" between centres on the 1024 as opposed to 30"+ on the P&W can be limiting with big drills too.
4) Both P&W and S&B have effective, quite easy to use, taper turning units but the double slide set up on the P&W is much easier to bring into action.
5) The P&W has a single tooth dog clutch in the feed and screwcutting drive making turning or threading to an accurate shoulder trivially easy. One day I shall arrange an electric equivalent for the S&B.
6) The P&W has a quick withdraw system built into the cross slide assembly which is a great help when threading. The technique I use on the S&B is equivalent but slower and inherently cumbersome.
7) The P&W cross slide dial reads diameters not cut which I loathe, YMMD. The S&B has dual imperial / metric dials which are great.
8) The S&B has an accurate saddle travel scale, albeit metric only, so little need for a DRO set. The single tooth clutch on the P&W makes it relatively easy to work around the lack of a travel dial. My 6 position bed stop fits both.
9) The P&W has a clutch, the S&B doesn't so a bit more care is needed when starting.
10) The P&W is imperial, the S&B metric. I have a full set of imperial thread cutting conversion gears for the S&B but the standard way of changing over is an incredible faff. Things got modified to make it much easier.
11) The 1024 takes 5C collets direct in the spindle which is useful, I'd not like to go back to a collet chuck. Full sets of imperial and metric 5C weren't cheap!
12) The P&W has a two speed motor and tops out at 750 rpm in 8 speeds, the S&B runs to over 2,500 rpm in two continuously variable ranges. I rarely run significantly over 1,000 rpm so the lower top speed of the old P&W isn't a great handicap.
13) Both have full flood coolant systems, which are pretty much too messy to use, and Bjur mist systems modified to semi-fog buster style which can be incredibly useful. Most especially when parting off. Factory trim full mist version of the Bjur makes for an unpleasant environment tho'.
If I had to go down to one lathe I'd keep the P&W! Little chance of that as anyone wanting one will have to prise it out of my cold, dead hands.
They weigh in at over a ton each.
|Thread: Fast charging anyone?|
Ignores the energy losses in the charging process.
Fast charging is inevitably more lossy than slow charging. Battery temperature rise during charging has always set the hard limit for how fast you can charge.
Probably something at least equivalent to 10 kW on a 5 minute charge of a 50 kWhr battery. Mostly generating heat fairly deep inside the battery too so cooling will not be trivial. Cooling is why Tesla battery packs are lots of small cells and relatively space inefficient.
Objectively Aluminium-Air is probably the best technology for reliable, simple, fast charging at rates equivalent to filling a petrol tank. But they are consumable primary cells so you can just haul the old ones out and swop a new set in. The energy storage density is very high so it could be practical to use several "200 - 250 mile rated" units per vehicle. If you had 5 units in your car planning to generally swop 4 at a time gives you a decent margin to fit the change in. The issues with aluminium-air is making them economically re-cycleble which means getting high efficiency without unfriendly chemicals and very pure metals.
If Elron gets his green rocket fuel generation system working adequately efficiently to produce hydrocarbons by cracking atmospheric CO2 and water this whole BEV thing will start looking like an early adopter fiasco of similar order to CFC bulbs. If you want to cart significant amounts of portable energy around hydrocabons beat the pants of everything else. We already have effective ways of storing and handling hydrocarbons as well as efficient ways of burning them to release the energy.
|Thread: Telescopic Bore Gauges|
Telescopic bore gauges seem to be one example of where decent quality used but looked after is better than brand new. Run in rather than worn out seems to be the thing.
I have a cheap import set bought as being all I could afford on first job wages which is rough to handle and very hard to get good results from.
I also have a couple of M&W sets bought used, one with 3 gauges and one with 5 plus some odd Starrett and M&W ones obtained somehow. Probably a "I'm throwing the box out, anything you can use?" type source. The big ones in the 5 piece M&W set have very little use and are noticeably less smooth than the more used ones but still way, way better than the imports.
The nicest one is a vey well used and, when dug out of a throwaway box, somewhat rusty Starrett. I nearly didn't keep it but it filled the gap in my odd ones collection so I cleaned it up with gratifying results. Officially my tooling / measuring "odd ones" sets are loaners to ensure my good ones don't get abused but I'm not sure that I want to lend this one.
|Thread: Motorcycle General Discussion|
I suspect your talk would have been given by Dr(?) Gordon Roe. Probably related to this paper published in SAE Transactions of 1984 **LINK**.
As I recall it he subsequently attempted to patent his version of the leading link design claiming that any safe version had to have the same stiffness characteristics of his as derived by Finite Element Analyisis. Something that sound like nonsense. Certainly Tony Foale, who actually built a fair number of leading link systems for solo motorcyles, strongly disagreed. One day I'll track down a copy to verify the maths myself.
The issue with leading links has generally been the difficulty in affordably arranging an effective front brake without a relatively expensive to engineer parallelogram torque reaction system if its not to stand on tiptoe when braking. The pendulum effects of the asymmetric masses offset from the steering axis need to be considered too. Most noticeable with the full swinging arm Earls system, as anyone with experience of BMW or MZ so fitted knows, but less extreme variants suffer too. Allegedly the Ariel Leader /Arrow was given trailing links for this reason. The ent offset being much smaller. For production machines a tele fork was always said to be much cheaper than a well engineered leading link. Neater looking too.
My Norton Commanders would trash the XJ900 forks in about 50,000 miles. The inevitably loose fit of the split bush at the bottom of the leg letting things work around enough that the dry bearing coating was soon worn through leading to the metal backing wearing away the inside of the leg. I'm told by an inspector meticulous type that he found the slider bores weren't accurate enough as made to take a proper solid bush. He rebored them true and re-worked the end of the legs to take solid bronze bushes. Claimed a great improvement. But, after all that work, he would say that wouldn't he.
I suspect my habit swopping the standard twin piston brake callipers for XJ1200 four pot units didn't help prolong fork life. The extra front weight and non-existent engine braking of the big rotary decisively shifted the barely adequate in emergency performance on the XJ900 to scary inadequate when an "I'm sorry I didn't see you" moment looms. That was in brand new condition too before the seemingly endemic corrosion behind the seals issue rears its ugly head after a year or so. I've cleaned out the corrosion and fixed a fair few siezed and near sized ones over the years for folk. Who seemed more than happy with the results.
Unlike the morons who "fixed" the brakes on my official unofficial kid sisters XJ600 by discarding the rear seals leaving room for the corrosion to build up! Fortunately her brakes locked just at the end of my drive so retrieval was easy. Equally fortunately I had an ex Commander set properly refurbished before being put away with only 1,000 miles on them to swop in. But 10.30 pm on Sunday night is not a good time for major brake system work.
Your Stella Alpina picture reminds me that for my first run abroad included taking a K100RS up to the top and collecting a Tee shirt. Not an ideal venue, or bike, for first time off road.
Edited By Clive Foster on 17/01/2021 19:53:44
It always surprised me how tolerant the major motorcycle makers were of front fork flex. Especially on later designs.
Most of the earlier breeds had hefty front mudguards with equally hefty support brackets holding things straight but over the years things got slimmed down to the point of inadequacy. I guess riders of a "certain age", like myself, have distinct memories of the various machined alloy aftermarket fork braces sold in an attempt to alleviate the problems with large Japanese machines through the 1980's and on to the mid 1990's or so. Generally made to looks with no proper engineering input and, predictably, of little effect. It should have been obvious that clamping on the outside of where the top fork seal goes won't do much unless its so tight that the seal distorts and jams.
Design horrors like the Yamaha house style things fitted to the XJ900 et al with loose bottom bushes, tiny top bushes and serious clearance between the legs and slider didn't help. Those seem to have been designed on the assumption that twist was a good thing. I was somewhat surprised that the glass fibre front mudguard used with the Norton Commander fitment was considerably stiffer than the apparently quite solid metal brace used in Yamaha factory applications. Still twisted, but not as much. Tore up the "not sold as a separate part" bottom bushes quite effectively tho'.
The bushless, slider running directly on the leg, forks used by BSA/Triumph on the conical hub machines were probably the ultimate in optimism tho'. The mudguard being flexibly mounted on rubber bushes and thin wire stays specifically so as not to stiffen things in twist. Presumably to ensure things couldn't be assembled out of line causing the sliders to jam. Tolerances get pretty tight when you effectively have a sliding bush approaching two feet long. Substantial though they looked the four bolt end caps holding the spindle were never enough to stop the forks twisting sufficiently under breaking to earn the conical hub brakes a considerable reputation for inadequacy.
I had a one of the very rare Small Heath built five speed T150 Tridents with the full size exhaust port on the centre cylinder and, allegedly, certain other internal engine changes that never made it to the proper Meridian built production ones. Whatever it went "rather well" and definitely needed more stopping power up front. I obtained a double sided four leading shoe drum brake front wheel allegedly off an early TZ750 figuring that with suitably re-lined shoes it would be up to the job. As I needed to fit torque arm retainers I made a decent fork brace using a pair of old style Bonneville tubular top mudguard mounts cut and welded into a single unit picking up on the original mudguard bolts, One in front of the forks and one behind.
Test rides showed a great improvement in brake performance. I found that on a good dry surface it was possible to lock the front brake at about 110 mph. I figured that was good enough and sold the 4 LS unit at 200% profit.
Proving, I guess, that flex is a bad thing.
|Thread: Interesting shaper-Newey|
Link from IanT didn't work for me.
I found this one which is a scan of the sales leaflet **LINK** .
Looks as if you are supposed to use the tilting capability of the table to help get round the lack of vertical movement.
In milling machine terms a sort of Deckel v Bridgeport concepts I suppose. Although the Deckel does have vertical table feed which weakens the analogy. A lot!
|Thread: Ajax AJPR220|
The XYZ 2nd op machine is closer to the AJP400 than the AJPR220. Cost around £25,000 so its much more expensive, especially in real world "how long does it take to save up for one" terms.
That sort of price is getting into low mileage used Hass territory.
For real world folks I guess the price bands are up to £5,000, £5,000 to £10,000 and £10,000 to £15,000 and its a question of balancing how much performance for how much money and how much work.
Realistically most of us are going to be shopping in the sub £5,000 band which means either very small (in my terms anyway as I do 12" to the foot scale work on a Bridgeport) or lots of work.
£5,000 to £10,000 band is a total minefield from clapped out hand me downs to solid iron for conversion through nobody can figure out why it doesn't work to decent ex-training and top end of the hobby machines.
£10,000 to £15,000 is where you start to find good enough to just run ex-industry.
£15,000 up you have to think like a factory owner.
They have it at £15,100 and a bit on E-Bay right now.
Not a bad price for entry level professional training machine with all the casework needed to appease HSE. I imagine cleaning swarf out is going to be a pain.
Proper professional control from Siemens albeit bottom of the range. Allegedly some quirks when using those.
ER25 spindle which is unusual but advocated in some quarters for non production machines when multiple tool changes per job aren't a requirement.
Fits through a normal door and doesn't need 3 phase so much easier to install than a factory machine.
If you are going to be spending serious money and the relatively small table and travels are enough it looks to be a decent option. Much to be said for shiny new and up to date against ex factory with serious miles on the clock and older style controller or home brew conversion.
Big brother AJPR400 is more my speed though but bound to be too spendy!
|Thread: Removing powder coating finish from metal.|
My experience is that blasting isn't terribly effective at removing good powder coating unless very agressive media is used. Which may not be a good idea on thin wall bicycle tubing.
A couple of weeks back I had to remove powder coating from inside the brake drums of a pair of motorcycle wheel hubs that had been blasted and coated without appropriate masking. My Guyson blaster barely took the shine off it. But I use a relatively small grit size as must of what I do is for pre-paint preparation and lighter cleaning so I want to avoid surface damage. Ended up setting them turning in the lathe and carefully scraping the coating off. Very much not the way I'd choose to work but needs must.
|Thread: DTI Stand - Single Lock Type?|
Not so sure about the need for a high force magnetic base. Much to be said for one that is strong enough to support the gauge with the arm at full stretch but still weak enough to let you slide it around on the table with a decent push. I have one I can fine adjust by a sort of levering rolling action of both thumbs. Easy to get a decently controlled few thou' shift.
Consider getting one of the inexpensive single lock arms off E-Bay and adding your own base. Unlike Journeymans experiences my £10 (ish) arm works well. The arms are shorter than the usual gauge mounting types and more in tune with the space available on our smaller machines. The one I got to carry the Bjur nozzle and vice alignment dial gauge on my Bridgeport is about 2 1/2 inches between pivots.
That said, for most purposes I loathe the single lock, articulated arm gauge carriers with a passion. The Eclipse post and pivoted arm ones I use for gauge mounting have a screw adjustment that is easily set to a thou or less.
Edited By Clive Foster on 06/01/2021 13:46:37
Edited By Clive Foster on 06/01/2021 13:47:32
|Thread: 130mm independent 4 jaw chuck, does it exist?|
Far more important to worry about jaw size than exact diameter.
Historically 4 jaw chucks, especially in the larger sizes, tend to come in heavy duty and light duty types. Heavy duty types tend to have jaw sizes approaching those of next size up three jaw and light duty ones have jaws more like next size down threes. Heavy duty types have significantly bigger and heavier bodies too.
Heavy duty ones hold workpieces more securely but the bigger jaws can seriously get in the way on smaller jobs. Although the heavy duty / light duty split isn't so specific with chucks of the size you are considering different makes and models have considerable variation. For our sort of work a light duty chuck with its smaller jaws and less massive body is generally better so, other things being equal, go for the one with the samllest jaws.
Some of the inexpensive imports have been terribly cumbersome. Objectively, on a smaller machine like yours, if a job needs heavy duty holding power its better done firmly strapped down to a faceplate.
I have both for my Smart & Brown 1024, admittedly a larger lathe than yours. The heavy duty one comes out about once a decade!
|Thread: Removing lathe cross slide handle|
That needle roller thrust bearing has the air of being a later addition rather than factory fit.
Once you have the hole sorted its probably easiest to simply add shims behind the inner thrust washer to take up clearance. What it did with a similar sort of modification, albeit using dry bearing thrust washers rather than a needle roller to save space. Recess made a little too deep so the gap could be measured with a feeler gauge.
Frankly if you have the makings and just decide to go for it its quicker to shim or make a second, longer, collar after measuring the gap with your first effort than it is to futz about arranging adjustment and setting up just so.
I suspect the hole error occured when re-making the collar.
Ultimate bodge on the mal-aligned hole is metal loaded filler. If worked in well a good brand is well up to that sort of job.
|Thread: ELECTRIC MOTORS|
This picture **LINK** on instructables looks to be appropriate for your motor.
I'm not sure what the extra connections on the board pertain to. Normally only those needed for that actual motor are present. It's possible that its a dual voltage motor or a capacitor start and run one as these need more connections. Unfortunately I only have the Brook Gryphon datasheet for those and the terminal designations are different.
|Thread: Removing lathe cross slide handle|
The hole in the pin doesn't look very round.
Suggests a roll pin has been fitted in place of a taper pin originally used to retain the handle. As I recall it the couple of instances I've seen were very similar in appearance. If that has been done you need to figure out the small end and drive the roll pin back out the correct way. It will leave a mess and will need re-reaming.
I've found a soft wire brush is a good place to start on dials like yours. The small brass ones for Dremel and similar machines have worked well for me. Patience and a light touch.
|Thread: Start circuitry for a single phase air compressor motor.|
Single phase motors with no centrifugal switch to control the start windings aren't uncommon in larger sizes.
The necessary control gubbins and contactors would have been in the equipment. Some of the air conditioner motors can be a bit unusual. Think Wye-Delta three phase starter equivalent for permanent capacitor, pseudo two phase, start and run motors. Something to do with power factor and efficiency I imagine.
I have a Brook capacitor start 4 hp motor with that configuration sitting on the floor. Too good to bin. I used that one to run a compressor with two contactors and two start buttons. Just held the buttons down until the compressor was up to speed. I'd used a normal centrifugal start switch "compressor duty" motor previously which was subject to occasional stalls on start up if acceleration was slower than normal for any reason. Presumably not enough momentum to carry it over the torque drop when the starting winding dropped out.
If using VFD drives its often necessary to set the torque boost parameter when used with compressors. I found that out with a Hydrovane 502 which would stall out, or half speed, on the first start after standing for a while in cold weather.
|Thread: Problem with DRO's memory or with mine?|
Its probably good practice to get into the habit of locking the axes whenever you leave the machine. I've made a few oopsies on coming back to a machine and diving straight in without properly thinking through where I'd got to.
I considered the microswitch zero indicator idea but got into the habit of reserving one memory location for zero and locking the axes as a temporary measure until I got round to doing the switch. Never seemed worth the effort for what would, to me, have been small gains. I already have a couple of lifetimes worth of stuff on the"nice to do" list anyway.
I reckon you are overthinking the multiple zero thing. KISS is important when it comes to references. In practice you'd probably do better to use the DRO memory set-up to directly input offsets.
Taking the switch idea and running with it what I want is a DRO with a control output pulse when an axis counts down to zero. Hook that up to a relay in the feed drive(s) and instant bed stop functions with as many positions as you have memories. Or even the main drive on a lathe to give repeatable feed and threading stops. Especially if you add an electronic brake or use the power down feature on a VFD. Maybe something under one turn of the spindle variation with most machines.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.