Bit of a progress report and a question about hydraulic ram stock

Lots of acknowledgements follow:-
I've been quietly making the full set of Hardinge HLV apron gears with the cutters that I got at Ally Pally, rather than bothering Tim...
I've got three pinions left to do. All 14t, but one has to have 20 degree stub form teeth to mate with the existing rack, rather than the 14.5 degree full form teeth that is what my cutters are producing. Actually I need to make two of this form, since Brian Willis needs a replacement for his cross slide feed pinion.
Because of the presence of bearing journals close to the pinion that are a larger diameter than the base circle of the teeth, it is not possible to cut some of these pinions with a Brown & Sharpe type cutter or hob DAMHIKT. So I decided to grind a rack type tool to use on the shaper.
I've been getting my ex-work, scrap £75+VAT J&S 1400 grinder capable of running so that I can do the job at home, rather than take the Diaform wheel dressing attachment I got from Andrew Mawson into work and use it on one of their grinders.
I have connected up the bloody great 30A 415V invertor I got from Brian, a 240/110V transformer that I already had and the 3 phase transformer that Adrian picked up from Bristol. These allow me to direct-on-line start all four of the three phase motors in the grinder (and the ones in the rest of the shed :-)
I've got the hydraulic pump running thanks to a replacement motor from Charles, via Peter and rebuilt the completely seized up, valve block.
I've rebuilt the coolant pump and removed a couple of decade's worth of fossilized grit and coolant.
The double ended hydraulic rams that move the table look as if someone tried, unsuccessfully to pick up the grinder with a forklift under the table i.e. wrecked. The construction is very simple and I've got a couple of metre lengths of 7/16" silver steel on the way to make replacements.
But here's the question bit.
The original rams seem to have been very soft steel and may have been plated. I can't yet quite work out whether they were chrome plated or not. I can't see any signs of copper under the damaged areas and it's possible that the high level of polish on the good areas was due to running against the seals.
Should I go for plated bar for long term replacement of the rams and, if so, does anyone know a supplier for 7/16", polished and plated bar in 32" lengths? or is it reasonable to assume that the silver steel will outlast me and my children's children?
Hey, it's much more fun than working on the car and the garden in the pouring rain.
Mark Rand RTFM
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The reason the rams seem soft is that they are. Rams are designed t
bend not to snap mild steel would be just as good as silver steel a silver steel even in annealed form is quite brittle. MB
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On Sun, 13 May 2007 01:38:57 +0100, Mark Rand

I had very good and helpful service from http://www.cylinder.co.uk when I needed some bar for overarms for my mill. They respond to email enquiries and take cards over the phone.
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On Sun, 13 May 2007 08:22:07 +0100, John Montrose

Thanks, I'll give them a bell on Monday.
Mark Rand RTFM
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<Loads of good entertaining stuff snippity snipped>

someone tried,

table i.e.

metre
been plated.

can't see

the high

seals.
and, if so,

32" lengths?

and my

the pouring

Mark,
When the J&S 540 was moved into the basement workshop at SM&EE some bozoo bent the same rod not realising that the table 'gravity locates' IIRC the replacement rods bought from J&S were not terribly expensive, though admittedly less fun than making them at least you know that they are 'the right stuff'
AWEM
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On Sun, 13 May 2007 09:29:55 +0100, "Andrew Mawson"

I was worried that someone might suggest the simple option, especially as J&S are less than 25 miles away from me. I suppose that I'll have the satisfaction of making a couple of rods (thread each end 7/16"BSF, then cross drill one end for the roll pin locking it into the piston). That'll get me going and I can do the job properly in a little while. I must admit that I was going to ask them for the price of a couple of spare wheel arbours to see if they were competitive, considering the large amounts of swarf involved in turning them up from solid.
Regards Mark Rand RTFM
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wrote:

locates'
expensive,
especially as J&S

satisfaction
drill one end

and I can

to ask

were
turning them

G&M Tools had a whole load of wheel hubs that they were selling at £20 each iirc - fiddly things to turn up with the taper and the circular dovetail groove for the balance weights
AWEM
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Mark Rand wrote:

It depends on what the bushing the rod is running in is made off. Bronze? Then it should have a hard surface. Some plastic or very soft metal, then you can use the silver steel.
Got a hardness tester? Then you can tell.
Nick
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