Hardness Tester

I have a need for a hardness tester, and was thinking of making the Dave
Lammas design as published in ME in 1989 (August/September IIRC).
Has anyone here made this design? any suggestions, improvements, traps
to avoid?
David
Reply to
David Littlewood
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In article , David Littlewood writes
Seems no-one has any useful experience to put forward.
I went to Blackgates Engineering yesterday, and found that one of the casting patterns has got broken, and that since they only sell about one set a year they are not giving any priority to repair or replacement. I bought the last (incomplete) set of castings. Blackgates are AFAIK the only suppliers.
If anyone has a set of castings they don't need, or knows of another source of castings, please get in touch (david at dlittlewood dot co dot uk).
David
Reply to
David Littlewood
In message , David Littlewood writes
[snip]
As the result of two such examples of customer care, Blackgates is a firm I now avoid (see note below). Have you looked at the possibility of fabricating the part?
Note: Does anyone know an alternative source of "Curly spoke" slate wagon wheel castings (5" gauge, 3 3/4" diameter)?
Reply to
Mike Hopkins
If you think Blackgates are bad, just wait until you have reasonable and legitimate cause to complain to Reeves 2000 about casting quality and a certain female gets on your case!!!
--
Chris Edwards (in deepest Dorset) "....there *must* be an easier way!"
Reply to
Chris Edwards
In article , Mike Hopkins writes
To be fair, they have to be commercially minded about these things - if they sell one a year, it cannot take priority over other things, and I can't claim they failed in any duty to me.
Yes, I have looked at the missing casting, and it could be fabricated - that is why I bought the rest. Would be a bit of a chore though.
David
Reply to
David Littlewood
No, sorry. But you made me curious. A DIY hardness-tester? Which method? Did they find a cheap replacement for the diamond? :-)
Nick
Reply to
Nick Mueller
David,
I have a "Warman Penatrascope" that you can borrow if you want. It's a dimaond pyramid device and will take samples up to about 3" thick. As it's on my study shelf as an ornament, it's one of the few engineering things not crated and palleted. (I had to go and buy a battery charger this morning, as the four I have are inaccessably crated!!)
AWEM
Reply to
Andrew Mawson
Yup,
formatting link
Third one down, cheap enough for you ??
Reply to
John Stevenson
I've got an ancient Firth hardness tester, missing a few bits such as the testing ball and in need of a good clean, which you could have for nowt if you can collect it or maybe even speak to Charles, depending upon where you are. (I've got a much tidier version which I'm keeping).
Tim
Reply to
Tim Leech
In article , Nick Mueller writes
Hi Nick,
It uses the Vickers method, with a 30 or 120 kg effective pressure and a 138 degree tungsten carbide 4-square pyramidal cone. This is good enough for any steel, obviously not for carbides or other exotic stuff (for which you need a diamond). You have to grind the pyramid yourself, but as I have a Clarkson that should be easy enough.
Let me know if you would like more details.
David
Reply to
David Littlewood
In article , Andrew Mawson writes
Andrew,
That's most kind, I'll take you up on that, at least it will keep me going until I get around to making the Lammas one.
You should have said about the charger, I have one here you could have borrowed.
Any update on the move date?
Regards,
David
Reply to
David Littlewood
In article , John Stevenson writes
Thanks John. I have a couple of those exact ones, but I don't think the diamond shape is precise enough; also not sure if the setting is up to the pressure. I may give it a go when I've made the instrument, but for what I need to do a tungsten carbide pyramid will be hard enough.
David
Reply to
David Littlewood
In article , Tim Leech writes
Gosh, that's generous Tim - where are you? You speak of ball, do I take it that it is Brinell or Rockwell?
david at dlittlewood dot co dot uk
David
Reply to
David Littlewood
Don't get too excited, you haven't seen it yet Probably better approached as a good basis for a tester, than a tester which just needs TLC.
I'm near Warrington. It's for Brinell though with smaller ball and therefore smaller forces then the standard Brinell tester. The later version I have (variable force) can also be used with a diamond, not sure whether that applies to this one (fixed force).
Tim
Reply to
Tim Leech
In article , Tim Leech writes
Tim,
I travel up to Lancashire most months (unfortunately just got back yesterday) so I could come and inspect. Would it fit in the boot of a (large) saloon car?
Could you please send me your un-munged e-mail address to david at dlittlewood dot co dot uk?
David
Reply to
David Littlewood
engineering
charger
David, I'm arround tomorrow (Sunday) if you want to come and collect - give me a call. Move date not definate yet - contracts are signed but not yet exchanged - it's looking like 3rd week in October, but that is bang on when my Daughter is getting married !!!!
AWEM
Reply to
Andrew Mawson
Easily. Imagine an ordinary bench microscope, it's a little bit bigger but many times heavier.
Should be readily decipherable from here.
Tim
Reply to
Tim Leech
My regular onetel email is playing up yet again, I tried to email you from my Yahoo address & it's bounced back, host not found.
Tim
Reply to
Tim Leech

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