Member postings for _Paul_

Thank you gentlemen some very good food for thought.

Some more information:

Dimensions:

Length bell to bell 10"

Diameter 6-3/8"

Shaft Diameter 5/8"

Running (unloaded) RPM 2970 (difficult to load up as it's a T&C grinder)

Voltages:

L1 - L2 = 250v

L2 - L3 = 230v

L1 - L3 = 240v

Voltage mismatch is down to the homebrew 2HP RPC it is running from.

Amperages:

L1 = 1.5

L2 = 1.1

L3 = 0.7

Above measurements taken with motor running @ 28 degrees C

And as they say a picture paints a thousand words....

Thats a 6" wheel in the pics.

Paul

I have a 3 phase motor looks like an older squirrel cage Brooks/Crompton sadly it's missing it's information plate.

What is the most accurate method of calculating it's KW or HP?

The motor is wired Delta and has an across the terminals resistance of 8.2 Ω dividing this by 1.5x gives a single winding resistance of 12.3 Ω.

Using Ohms law my calculations have given me this:

V/R = I. therefore 230v ÷ 12.3 Ω gives 18.6992 Amps (I)

230v x 18.6992 Amps = 4.3 Kw ÷746 = 5.765 HP

Looking at the size of the motor it dosen't seem big enough to be this powerful, but that said it won't run for long on my 2HP RPC before the switch trips out.

Any & all help appreciated.

Paul

Isn't Teflon more of an anti-friction/anti-stick agent?, my boss uses it on his desk....anything that lands there immediately ends up with me....

For a rustproofing IMHO a good mineral oil is better, Tesco Baby oil works well smells lovely too

Paul

All my Dormer brand drills are marked either with the name in a silver band or on the shank.

Paul

I remember the JB weld display stand in our local motor factors years ago had a display where they had stuck two motor car valve heads together...no one ever broke them apart.

I have five Shapers, these machines are subject to very high (interrupted) cutting forces.

If it were me I would CI weld using a Nickel rod of some sort.

Paul

Brightening = Polishing?

Electrolysis & pickling will leave a dull finish.

Polishing will remove metal, done carefully shouldnt remove too much, you might wish to try a fine "Garryflex" block metal finishing trades use them.

Paul

Edited By _Paul_ on 06/09/2012 08:33:57

Drives direct are very helpful, I have one of their Teco Inverters.

An cheaper alternative might be the chap I see avertise on Home Workshop goes by the name of Gavin Oseman.

regards

Paul

Both of Jim Cox's books are very good, another one you might wish to consider is Graham Asterbury's "Three Phase Conversion" also from the Workshop Practice series which I found very informative.

An excellent source of sensibly priced capacitors in the UK is Cricklewood Electronics.

Paul

Lol thank you gents

Really enjoyed the show spent far more than I started out to though!

There's a home made version of the Arc type in Model Engineers' Workshop Magazine No. 172 in this article:

A SWARF STICK
David Haythornthwaite discovers
better ways of removing swarf.

I made one it was cheap <£5 and works very well.

Paul

It always tickles me when I get the odd "herbert" introduce him/herself as an "ExSpurt" in something or other..........

It's hard to choke back the phrase "yes you probably are" ..........

Slight variation:

Ex = somthing past it's best

Spurt = Drip under pressure.

P

Not sure about all manufacturers but AFAIK most of the major ones.

I normally buy my wheels from Abtec either through their site or on occasion when they have a sale on eBay.

Just bought 2x PA 54 JV wheels from their eBay auction for less than a tenner with shipping.

Regards

Paul

Wheel info:

• (A) Brown/Blue Regular aluminium oxide abrasive. Grinding mild steels.
• (WA) White aluminium oxide abrasive for medium to hard steels.
• (PA) Similar to (WA) but with cooler grinding properties, chromium oxide added, to make the abrasive tough & good for precision grinding of alloy tool steels.
• (RA) Ruby this is a very tough form of WA abrasive, which is suitable for holding corners and standard steel applications.
• (GC) Green silicon carbide abrasive for tungsten carbide tooling.
• (SG) Light Blue a Microcrystaline abrasive which means it breaks down in micro parts, it is a high performance abrasive for very cool & fast stock removal of hardened steels e.g. Tool Steels.
• (454A) Blue ceramic abrasive for grinding hard to difficult to grind steels.

• Grit size. Coarser---24-30-36-46-54-60-70-80-100-120-150-180-220---Finer
• Bond hardness Softer---G-H-I-J-K-L-M-N-O-P-Q-R-S-T---Harder
• Bond type. V= Vitrified. B=Resinoid

Paul

How much!

Seriously though why not turn an MT2 taper on a bit of 1" bar and make your own arbour?

Paul

Looks really hefty!

Does it come with any backgears? the pic makes the fitted ones look quite fine sourcing additional ones could be a problem.

What are you cutting? & what are you cutting it with?

Paul

Thanks very much Harold I have peeked around your site in the past and never really found any problem with navigation.

The white background to the text makes the page look a bit weird tho.

Paul

The "Diamond Toolholder" is my personal favourite for most jobs, then a "Shear Grind" bit if I need/want a superior finish both use HSS tools.

Regards

Paul