Member postings for DMB

Springbok,

Snailmail just as awful in city centre - still waiting for my copy BN1 !

John

Richard,

Thank you for your input, very useful.

JasonB,

I understand and agree with your post. However, my point is that for most model engineering, HSS is adequate and el cheapo.

John.

went to "work" and spent day being paid to sit there reading latest MEW- cant be bad! Better than reading it @ home and not being paid. I am after all, only working part-time in my deferred retirement for a short while for a bit of extra dosh. Only need to answer phone about twice a day and a few other little jobs. Last week helped put up office Xmas decorations, assisted by a muslim lad! Dont believe all you read in newspapers about them being offended by Christainity. Probably only a few fanatics give them all a bad name.

When you use a certain 4 letter verb as a conjunction, it loses much of its impact and makes the lot sound like a torrent of abuse. Is it really necessary?

Also some of the things done/said in the name of "entertainment" today, e.g., "Lady" Gaga. Joke title if ever there was one.

Lee,

What do you mean, "dont get it on concrete floor"? DONT ever use that nasty stuff inside any enclosed space. For sake of your future health, always but always outside in open air - fumes!! I have used it ,outside of course, to get black mill scale off hot rolled steel plate. Works a treat!

Hydrochloric, Sulphuric Acids and the Strong alkali, Caustic Soda. Use them all only outside with eye protection and upwind of the container. Keep container protected from birds and animals. If you have an accidental spill, neutralise with opposites - acid / alkali.

Hope you all take great care for selves and innocent wildlife/pets.

John

Wiring Pt 4

Drum terminals 4 & 8 not used.

Block terminals 1 & 2 not used, in diagram but use say 1 for earth connection, not shown on diagram. Ensure you have a complete run of green and yellow striped earth wire from mains lead to block to motor casing, securely screwed-up tight. Also ensure that stand and lathe also connected. Beware, if you use cork washers under motor bolts to deaden vibration, you need to earth actual lathe, just in case....

Manual says "N.B. When a push button starter, with or without isolator, is fitted, the supply should be connected to it (or to the isolator), NOT to the terminal block."

Standard recommendation is to use a no-volt isolator for on/off and drum switch for merely reversing the motor.

As I dont have an isolator and just use the 3-pin socket switch, I cannot help with wiring in an isolator.

If you want, I will try to scan and send diagram to you. If the above connections fail to effect a reversal, you need to swap a pair of like wires to the motor, say A1 and A2 or T2 and T3.

If in any doubt obtain assistance of a qualified electrician as I cannot accept any responsibility for the previous posts.

Wiring pt 3 - Correction to motor wiring:-

Red from block 8 to motor Z2 / A2.

Sumarise -

Drum - Block - Motor (in line as per diagram):-

7-7-T3, 6 -8 -A2, 5- 5-T2, 2 - 6 - A1.

Mains - Block - Drum:-

3 -3, 4 - 1.

Wiring post part 2.

TERMINAL BLOCK TO DEWHURST SWITCH:-

Black wire from block 3 to drum 3. Red from block 4 to drum 1. Black from block 5 to drum 5. Red from block 6 to drum 2. Black from block 7 to drum 7. Black fro block 8 to drum 6.

Hi Stephen,

Back home now and access to my S7 manual. It shows wiring diagrams for 1 phase on the Santon reversing switch and both 1 & 3 phase on the Dewhurst drum type reversing switch. Only the 1 - phase diagrams show the 4 colours listed by you. The motor plate in diag. shows A1,A2,Z1,Z2. My motor has 4 terminals marked A1,A2,T2,T3. My notes show Z1=A1, Z2=A2,A1=T2,A2=T3. On the back of the non-industrial, folded and welded stand, there is a brown terminal block numbered 1 - 8.

MOTOR wiring:-

Mains Neutral goes to 3, Mains Live goes to 4. Blue wire from 5 to A! / T2. White wire from 6 to A1 / Z1. Green wire from 7 to A2 / T3. Red wire from 8 to Z2 / T2.

See next post.

Hi John,

I am thinking a rear toolpost with swivelling top cap with one angled blade and one level. The horizontal one will give zero `top` rake for brass and the angled one has `built-in` ` top` rake for steel, both blades being ground identically, just mounted differently.

Dont fully understand your remarks about overhang as if the front face of the cutter is at centre height when touching the circumference of say a 1" D. bar, then the tools leading cutting edge will still be on centre height when it has cut the bar down to 1/2"D. and will still be at same height when it reaches zero Dia. and the work is finally parted off. Having said that, I would probably stop and re-set tool projection when half-way through that sort of diameter.

John.

John,

Quite agree. "Nothing new under the sun" as they say but always learning something.

John

Edited By DMB on 26/11/2013 10:59:16

I think the explanation for Mamod, Wilesco and any similar, being made of brass is because you fill them up to a certain level to run for so long, bit like a steam Iron. Packed away dry. They are very small, low pressure and in the unlikely event of explosion would probably only injure the idiot abusing same and no-one else. Probably, the low danger level is reason that they appear to slip under the wire for Pressure Vessel Regs. The bigger capacity and very much higher boilers capable of real harm come under the regulations governing combined pressure/volume.

Water only boils @ 100C/212F @ 14.7psi(atmospheric) and as the pressure climbs so too has the temperature have to climb in order to continue making the hot water actually boil and produce more steam. If there is a sudden and serious burst failure of the vessel releasing all of the accumulated pressure of steam, the hot pressureised water is immediately way above its natural (100C) boiling temperature and will immediately convert to steam at around 600 times its original volume, hence the violent explosion and severe scalding of anyone nearby. I have recently read an account of a dodgy small soft-soldered boiler in a model boat which blew up about 100 years ago, I think it was at Kensington Round Pond. That was lack of water and interference with the safety valve. There have been a number of wrecked traction engines in years gone by and photos have appeared in old MEs.

John