Member postings for Chris Pearson 1

I trust that if a socket is to be provided, consideration has been given to compliance with 553.1.201 of BS 7671.

1) What 5.5 kW 230 V supply do you intend to use?

2) My own VFD warns against not using it for a year or more - the capacitors do not like it.

It's not quite as simple as that. I had thought that 40 years of contributions would get me the full amount, but I have to keep paying NI (and keep working) until my 66th year for that.

There is an option of deferring one's claim, which results in a larger annual amount; but obviously, for fewer years.

Well, if it passes the usual tests, it will not blow its fuses.

It will be easier to consider the problem if you post the wiring diagram.

You really ought to test properly rather than big bang testing. Have you a wiring diagram?

Two fit blokes, or hefty women, could carry a 7 series Myford up a stairs without too much bother. What you mount it on is another matter entirely.

I think that it goes without saying that you take off the chuck, tailstock and carriage, and even the motor, but I prefer to leave the headstock undisturbed.

Edited By Chris Pearson 1 on 15/02/2023 23:08:03

I would expect to find 3 links in the terminal box. They could go A2-C3, B2-B3, C2-A3; or A2-B2-C2 and the supply cables would be to A2, B2, C2.

Are those resistances with all the terminals independent, or with links installed?

It would be more useful to see the motor's terminals please.

The 6 wires will be the ends of the 3 coils. You need to ensure that you have the motor correctly wired in delta or star as appropriate. What do the VFD's instructions say?

Edited By Chris Pearson 1 on 15/02/2023 18:42:22

With respect, 3 kW is not correct.

I suspect that the motor is 1/3 h.p. so it will draw 1 amp under load and up to 6 A briefly on starting. A Dewhurst switch will certainly cope with that.

I never had a problem with mine on an S7 so a slightly bigger motor.

The advantages of a separate NVR switch are (a) if the power is cut, the motor will not start up again unexpectedly when the power is restored; and (b) there is the option of an emergency stop mushroom button. However, it is certainly not a necessity.

It looks lovely - enjoy it!

Edited By Chris Pearson 1 on 11/02/2023 11:22:54

This is the "push" type on a 254. I cannot understand why there is a gap between the bracket and the bed.

Incidentally, the clutch in the saddle drive is adjustable to the extent that it may be set to slip so easily that it wouldn't turn the skin off a rice pudding, so there is little risk of damage when the saddle comes up against its stop.

Now that I have had my tea, I am thinking more clearly. I can see that the only way a saddle stop would work on the small Myford is by manual advancement of the saddle.

That Super 7 one is all very well, but it would appear to work only within a couple of inches of the headstock.

The Hemingway one looks good, but where is the saddle?

Which type of saddle stop? There appear to have been two types, at least for the 254.

There is what you might call the "pull" type, which has the stop behind the saddle with the turret secured to the back of the bed. Then there is the "push" type. It has a short rod attached to the LH side of the saddle and comes against a turret which is fixed to the bed in the desired position.

I am not sure how a saddle stop would work for the small Myford. Do they not depend upon the friction clutch in the drive mechanism?

Happy to provide further details of either.

ETA, just to add to the confusion, there have been incomplete cross-slide stops for the 254 on eBay for a while. I cannot quite see where they would go.

Edited By Chris Pearson 1 on 08/02/2023 19:10:14

That is not quite correct. I&T is to be done i.a.w. Part 6 of the current edition of BS 7671, which is 18th Amd 2. So your plastic CU gets a C3. Similarly, lack of RCD protection would get a C3 for each unprotected circuit. If testing were to the edition which was current at the time of installation, things like lack of earthing might be acceptable.

If legislation were to specify the current edition, it would be "ambulatory", which is to say that BSI/IET would change the law every time that BS 7671 was updated. This would never do because only Parliament can change the law.

Yes and no! Have a look at R. 3 of The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020. The inspection and testing will be to the current version of BS 7671, but that does not necessarily fail an installation i.e. C1, C2, or FI. A reasonably modern installation in good condition may get some C3s, which means that improvement is recommended, i.e. bring it up to the current standard.

Your C2 sounds dodgy, but without seeing the lamp fittings, it is impossible to say more.

The quality of EICRs is a recurring theme in an IET forum where you will get a reliable response to your question. Try here: https://engx.theiet.org/f/wiring-and-regulations

OK. I have levelled my lathe. By that I mean that the bubble in the level is at the same place at both ends. So it slopes a bit back to front at both ends, but by the same amount. It also slopes a bit along its length as does the floor. This is all measured with an engineer's level.

The instruction book for a Myford 254 describes levelling the cabinet and then the lathe.

Well, they don't. Yes, they may be accurate enough for some purposes, but the deck cannot be guaranteed to remain true.

I distinctly remember raising this point when I first went to sea in 1990.

I cannot see the point. You would have to level the lathe every time that the castors are used.

I once tried moving a bandsaw on castors which were supposed to be suitable for the load - they lasted about 6 feet. In the end, I "borrowed" the ones under a large Snap-on tool chest.

Ah yes, but in my experience (provided that you are buying some meat) bones are buckshee.

They were usually made of bone. If you can find a proper butcher, you may be able to get an ox's femur.

WD40 - plenty of it.

Also keep it dry.