Member postings for Clive Foster

Colin

I don't know if the stuff I have or that on the motors I did actually is shellac but it clearly builds thin layer of insulation over everything.

I imagine the idea is to stop the string moving around due to vibration so it doesn't eventually work its way through the insulation coating on the wire causing turn to turn shorts. Clearly a bad thing. As I understand it the wire in the coils have vibrational forces on them when the motor is running, think transformer hum, so some sort of restraint is needed.

Clive

Edited By Clive Foster on 28/01/2022 09:43:38

On all the motors I've done shellac, varnish or similar protective coatings had been applied after tying. So things still stayed in place after snipping the string.

Adhesion wasn't high. More than post it note, less than sellotape. So some careful pulling and prising with non-metallic tools got the bits I needed to work on up and out into free space with minimal disturbance to the rest.

I left most of the old string behind as it clearly wasn't going to come out easily. Just snipped the trailing ends neatly close to the wiring. The coating soaked string was approaching MIG wire stiffness. Re-tied with some nice cotton string 'cos I had some.

Dunno what the modern advice is on re-coating. I "obtained" a small bottle of the then proper stuff about 40 years ago. Behaves like shellac in that it separates out of the carrier liaquid quite quickly and needs regular stirring up.

Clive

Not so sure about kitchen worktop as a benchtop. Its very smooth and slippy for easy cleaning so stuff tends to roll off. Not helped by the nicely curved edge. Generally the top surface is quite easily damaged too. I've always found it unpleasant to work on when doing mechanical or other workshop type jobs.

The labs I worked in at RARDE / DERA / DRA had heavyweight lino tops on teak(?) support structure with poper, carpentry made cupboards beneath. DRA management decreed modernisation pulled the whole lot out to replace with cheap metal frames and legs, smooth melamine tops and kitchen cabinet style cupboards. Total and utter crap. Much less pleasant to work on. Pretty much a riot from the worker bees once we realised what was going on. Management got bonuses for spending a fortune making things worse.

Heavyweight lino and a suitable under support is probably too expensive for normal folk. Especially as it needs a nice battening around the outside edge.

Consider a moisture resistant T&G flooring board with the slightly rough surface, such as Cabertek P5 (but do look before you buy), as an alternative. Not silly expensive, so binning if damaged doesn't hurt too much. The rough surface stops things rolling too far but isn't so rough as to be damagingly abrasive. I usually pin a softwood batten on the edge with a tiny bit of upstand over the surface to further help control rollers. Perhaps 1/2 mm or a bit more so no great impediment to sliding heavy stuff off.

Great for shelves too, with a bit more upstand on the edge batten, 1/16 or so, on high ones! Upstand is a bit annoying on high ones 'cos I have to get the fold up step stand out rather than drag stuff off at head and above height. Enforced safety is probably a good thing as drag off has come close to being more than a bit risky in the past.

Clive

Roger

Many of the electromagnetic clutches used on machine tools had adjustments to set the plate gaps for proper operation. Infrequently needed so by the time it was required the book would have been long lost so folk guessed. Which rarely ended well. Generally finding the proper procedure and following it sorts them. But the plates may need a good clean first.

Coils have been known to burn out after many. many years. If so you are probably stuffed as most makers have either died or pulled out of the market. Coils are invariably encapsulated and more or less "everything proof".

Retrofitting with a modern device may be possible as may be coming up with a mechanical work around.

Clive

john

If you don't also have at least the carrier that fits to the back of the saddle as well as the part in the picture I'd advise against trying to reverse engineer the Boxford system and make new parts. Its very difficult to get right.

Because you have dovetail slides both below and above the central bar there is no vertical flexibility. So the system has to run absolutely flat and level in both sets of slides. The tail end bed clamp must also sit at exactly the right height. Tolerances are basically zilch!

My old SouthBend Heavy 10 had the same set up and getting it just right to get smooth movement with no drag both when ordinary turning and when taper turning was a right pain. Ant that was factory fitted kit exploiting SouthBends usual babbit filling technique to ensure the tail end bed clamp alignment was correct. Mine had been removed and refitted "not quite perfectly" by the previous owner to paint the machine so there was enough drag when in taper turning mode to twist the saddle a little upsetting the actual taper set and cut.

Not a great fan of having the loose tail end bed clamp dragging up and down the bed all the time during normal work either.

In your position I'd cannibalise it by fitting an angle bracket underneath to bolt to the bed and bolting either a U channel or square / rectangular block onto the taper setting part. Easy to allow a bit of space for vertical misalignment in a simple solid or U shoe follower. Its all lots easier. Thats the way folk like CVA, Holbrook, Pratt & Whiney (U channel) and Smart & Brown (rectangular block) do it. I figure they know what they were doing.

Never really understood why the system fitted to Boxfords became popular. Lots of extra fitting and precise work needed to get the sole, tiny, advantage of being able to immediately taper turn anywhere along the bed.

Clive

Dave

Thanks for the information on your battery system. I've copied the text and popped it into my mulling over file.

Great to have information from real users.

The Solar Sofar prices are very attractive when compared to Tesla. Order of £3,000 against £8,000. So payback time is getting into the region where it makes sense.

But the Tesla Energy plan is an attractive concept if it actually works to ensure I can use all my solar panel output.

Back to mulling!

Clive

Chris

My panels are on my workshop roof.

OK big workshop so room for the the full 4 kW set so it was a no-brainer really. No way was I letting the panel fitters loose on my new roof after having an extension made. None of the companies I talked to seemed to have any idea of how to handle a properly tiled roof using old style Marley tiles with full overlap where the upper tile has a small overlap relative to the next +1 tile down with one tile in between.

Clive

John

Puddling works a treat on a nicely ground open crack.

But I would say that wouldn't I.

I start with 1.6 mm rod at about 30 amps on my Fronius inveter welder. Move up to 2.4 mm or 3 mm when its time to close the gap.

For drill holes I find Devcon metal loaded filler much easier to use and get a nice flat surface on than weld. JB weld always seem soft to me and tends to flow during setting which makes for a harder job. Especially if you can't lay the surface to be repaired flat.

Devcon isn't cheap and smallest tub is relatively large for home shop types so I don't always have any to hand and have to weld.

If the drill hole is just a dimple then 1.6 all the way.

Deep ones I tap, screw a stud in then weld over the top.

Clive

The actual composition of the iron in question makes a huge difference to how well and how easily it welds.

Had to repair a broken eye on the banjo bracket of a 1960's SouthBend lathe. Allegedly made from what the Americans called "semi-steel" ie cast iron with a fair bit of steel scrap in the mix. Welded like a dream. Heck I've had more trouble with plain ordinary mild steel.

Good links from Nick but my, admittedly limited experience, is that the specialist electrodes are biased towards the professional needing to do a relatively fast job so the customer can afford it. Flip side is you need the experience, skills and equipment to do it right. As always with welding getting the speed of motion and volume of the weld puddle right is very important for best results. The more specialist the rod the more important this becomes.

Puddling with an ordinary rod takes ages but its very tolerant of less than ideal technique.

Which is why I use it.

I just don't do enough welding of cast iron, or any other weldg for that matter, to get professional standard good.

Clive

Dave

Bit off topic but what battery set up do you use?

I have panels and am mimbling over whether or not to add batteries. Few firms offering turnkey products now but I'm wondering if the market has matured enough yet.

Clive

I've repaired cast iron with both stick and MIG with only home shop facilities so no pre-heating.

MIG, in my hands at least, tends to come out brittle with a tendency to crack on cooling. On on older "economy" cast irons MIG doesn't deal well with the high free carbon content.

As Ady1 says using stick in the normal manner tends to give you slag problems and cooling contraction may crack things.

Avoid the specialist cast iron repair rods unless you have preheat facilities and the skill to use them as per book. Wonderful if used properly but in the Home Shop you are highly likely to end up with glass hard pigeon droppings and an unsalvageable job.

How do I know. The unsalvageable job came to me after an "I know what I'm doing expert" messed up.

Best way I've found is to use small stick rods with a puddling technique. Which, back in the day, was the approved method for field repairs.

Choose a nice ductile rod if you can.

The DIY specific market rods from reliable suppliers tend to be good at this. But avoid the "cheap for DIY market" from "who the heck are they" folk. Some of the no-name, white box imports can be really odd and the alleged type numbers clearly not what is in the box. That said some white box no name are superb. Inherited two boxes from a friend that were wonderful. No idea what they were because the number corresponded to something rare, expensive and a right pain to use.

Puddling technique is basically to clean up as well as you can first then apply a thin layer of stick weld using a small rod and the lowest current that will give good fusion. Tap with the chipping hammer as it cools. The peening largely counteracts any stresses due to cooling contraction. The thin layer and relatively low temperatures minimises carbon migration into the weld metal. Allow to cool properly and repeat. After 5 or so layers you can switch to a larger rod for faster build but still don't try it in one. Peen when cooling as before. As you are now welding rod material to rod material carbon migration isn't an issue. Using a ductile rod helps reduce cooling stress too.

A good inverter welder makes life easier than an old fashioned buzz box. Victorian architectural brackets et al have lots of free carbon. Welcome to the coal miner chic look! Jobs to avoid.

Slightly OT here is a pro repairing a cast iron vice without pre-heat.

**LINK**

https://www.youtube.com/watch?v=KX7ajWCxpcM

He broke it so he fixed it.

Clive

PS There is a build of one of his big "weld up from plate" vice design in my future. Just have to source the tubes.

Edited By Clive Foster on 21/01/2022 20:14:33

Edited By Clive Foster on 21/01/2022 20:15:38

Speedy Builder

Thanks for the Crocell link.

Been wanting some in a fairly desultory manner for some years but never manged to track down a supplier.

Clive

Seen notchy issues in similar screw feed systems from bent shafts, worn bearings and a thrust bearing slightly tilted in its housing.

The only specific lathe one was a bent shaft.

Well apart from the totally WTH case where the ball thrust race at the back end of a taper turning SouthBend Heavy 10 had been assembled with two ball cages between the thrust washers. How that level of brain fade happens on re-assembly I shall never know.

Clive

VCI paper + plastic bag, clingfilm or similar to seal the atmosphere out will do fine for "years" in any inhabitable space. If you bring things indoors a plastic box or securely lidded tin will do nearly as well on its own. Stick it in the back of the airing cupboard if you want to be inspector meticulous.

Main thing is to avoid damp environments or ones where the temperature regularly cycles through the dew point.

I don't care for nostrums on anything that might need to be painted. If the stuff sticks well enough to prevent rust getting it all off can be hell on wheels. None of these things seems to come with an official solvent.

The wax dip stuff that you used to find on new cutters to protect the edges is very good for small things. It comes off clean with no deposit. Not, I believe, the same formulation as the dip stuff used to sleeve handles. That seems to be sticker so bits get left behind.

Now leaving things in the garage with the usual ill sealed door will be a whole n'other thing.

Clive

Colin

Pleased to hear that IDS were their usual helpful selves and that you were able to order some suitable VFD boxes.

In objective business terms I'm sure it can't really be worth their while to spend so much time with small customers but it must be really good for their reputation. Gives you that nice, warm fuzzy feeling of dealing with a trustworthy supplier and makes you confident that if, perchance, something doesn't go to plan they will help you sort things out.

Which reminds me I need to order a couple more VFD boxes later this year.

Clive

Andrew

I suspect the confusion about torque and power loss was due to thinking in DC motor terms where half the voltage means half the current which means half the torque then if running at half speed you have 1/4 power. Or something of that lik.

Clive

Getting back on topic it seems that you have fallen foul of one of the security demons protecting the information accessed via your Apple ID. Apple does take security of user information pretty seriously and has automated procedures intended to prevent an unauthorised user taking control of your Apple ID and thereby getting access to your data.

I presume it interpreted transfer to the new phone as being an attempted hijack and blocked the account. Presumably with both phones being close together the system assumed that your original phone had been stolen so a nefarious person could be assumed to have control of both phones.

If you have an Apple computer with access to the same ID it should either still work, so verifying that the ID still exists and is live, or at least provide the independent verification needed to re-construct access. Which, as I understand it, is deliberately made not easy. If the ID is just on the phone it may well be gone for good, along with your data. There are some triggers for an automatic block / wiping of the ID which simply cannot be unwound. Especially if your data is encrypted.

Most likely I think if the new phone has the "secure enclave" and the old one didn't. Secure enclave is supposed to make it easier to handle secure data and to verify that the owner is in control of the phone but it demands pretty careful following of the procedure. I'd not care to go from a non secure enclave phone to one with it via the automated procedure. Too much potential for hard fails. I'd certainly not care to do so for a second hand phone where you cannot be sure that the secure enclave has been properly cleared and re-virginised.

You just have to hope that your local experts haven't made a major error and locked everything down. Usually Apple provides a way back for typical "inadvertent customer" type errors.

Fingers crossed.

Clive

Does anyone know, or have any resources allowing reasonable calculation, how much power is "enough" for a Home Workshop type Bridgeport user?

Less than any industrial user by some margin I'd think. Having to pay for both machine and cutters from whatever fraction of what's left over after covering the essentials defined by the distaff side is a strong disincentive to running sufficiently hard to shorten cutter life or damage the machine. Percy Piecework tends not to worry about short cutter life as the firm is paying!

My Bridgeport has a 1 1/2 hp 2J2 (Varispeed) head and I know I've never come close to running out of spindle power despite having it shuddering a time or to with ambitious cutter sizes and feeds.

Generally I run speeds and feeds about 2/3 rd that given in my old "Osbourne" free gift slide & box cardboard calculator. Which seems to work well enough that I'm not overly inclined to go hunting for "better".

Given the known inefficiencies of the Reeves drive on the Varispeed machine I'd be unsurprised to discover that there is little more than 1 hp at the cutter. The drive cover gets pretty warm indicating significant power is getting lost somewhere up there.

As Colin has the more mechanically efficient Vee belt drive head I think it quite likely that the 2/3 rds hp he will get from simply connecting his 1 hp star connected motor to a 230 volt Vfd may well be sufficent for anything he is likely to want to do. I woud be unworried about speed limitations. Mine goes ofver 1,500 rpm about every second muckspreading after the third blue moon of the year. Around August 2018 last time. Probably.

Clive

Edited By Clive Foster on 17/01/2022 18:38:59

Andrew

Inverter Drive Supermarket have a nice blog post covering running a 400 V (nominal) star connected motor from a 230 V (nominal) inverter.

**LINK**

https://inverterdrive.com/HowTo/240V-Supply-to-a-400V-AC-Motor/

Basically you get full torque up to 29 Hz where the motor runs at 2/3 rds the nameplate speed so you do indeed get 60 % of the power. Theoretically 2/3 rds, 66 % but I imagine there are various detail devils deciding exactly how much.

Moi?

I'd work on 50 % of nameplate power and expect a healthy safety margin to exploit.

Hmm. Wonder how much air a Hydrovane makes at 2/3rds speed?

Clive

Edited By Clive Foster on 17/01/2022 17:59:00

Edited By Clive Foster on 17/01/2022 18:11:19

For all practical purposes slip gauges with smooth but non wringing surfaces can be stuck together with a heavy oil or light grease. Sparingly applied and worked to extrude excess.

It will produce a positive tolerance build up but for two, three or four blocks joined together we certainly aren't going to notice.

I have a truly disgusting set of slips, found loose in the box of bits that came with a used lathe, which I use to set up the turret style bed stop on my lathes. More than good enough and I don't worry if one does take up temporary residence in the chip tray.

I also have brand new metric and imperial sets of Weber slips obtained on a whim at a price too attractive to pass up along with the two E-Bay "some wring together" bargain sets I'd previously gotten which work well enough if oil assisted.

As I also have some nanometre precision Heidenhain probes it might be interesting to set-up some tests to see exactly what the relative accuracy of the sets is in practice. I suspect the poorer sets would give rather better account of themselves than might be expected from casual thought.

But life is too short. If I put the exercise onto the to-do list now it will get to the top around 2050.

Clive