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Model Engineering in UK - Model engineering, metal crafts in UK
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Posted by dave sanderson on March 1, 2008, 3:05 pm
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evening all,
whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
noticed my tailstock is low, by about 8 to 10 thou. Is there an
accepted way to shim this up? I have currently got 8 thou of feeler
gauges in both ends, but its not quite perfect (by indicating inside
the MT on the ram). unfortunately Im not sure exactly how much its off
due to the bentness of the indicator pin (bent up to contact the taper
without the indicator body touching it) which gives a cosine error
IIRC. <rant>Its a PITA to add another shim, as you have to dismantle
the thing, and then recenter it so you can take a hi/low reading. Im
sure Ill get quicker, but it took 2 hours last night to get this
close.....</rant>
Are feeler gauges ok to use as the final shim solution? I seem to have
inherited about 3 or 4 sets, so have spares.
cheers
Dave
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Posted by Andrew Mawson on March 1, 2008, 4:10 pm
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> evening all,
> whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
> noticed my tailstock is low, by about 8 to 10 thou. Is there an
> accepted way to shim this up? I have currently got 8 thou of feeler
> gauges in both ends, but its not quite perfect (by indicating inside
> the MT on the ram). unfortunately Im not sure exactly how much its
off
> due to the bentness of the indicator pin (bent up to contact the
taper
> without the indicator body touching it) which gives a cosine error
> IIRC. <rant>Its a PITA to add another shim, as you have to dismantle
> the thing, and then recenter it so you can take a hi/low reading. Im
> sure Ill get quicker, but it took 2 hours last night to get this
> close.....</rant>
> Are feeler gauges ok to use as the final shim solution? I seem to
have
> inherited about 3 or 4 sets, so have spares.
> cheers
> Dave
Not familiar with the L5 tailstock construction, but when doing a
similar job on my Colchester Master 2500, I started with feeler gauges
to set it to where it should be, then cut custom flat shim from
shimstock to give a larger surface area.
AWEM
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Posted by dave sanderson on March 2, 2008, 3:44 pm
Please log in for more thread options wrote:
>
>
>
>
> > evening all,
> > whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
> > noticed my tailstock is low, by about 8 to 10 thou. Is there an
> > accepted way to shim this up? I have currently got 8 thou of feeler
> > gauges in both ends, but its not quite perfect (by indicating inside
> > the MT on the ram). unfortunately Im not sure exactly how much its
> off
> > due to the bentness of the indicator pin (bent up to contact the
> taper
> > without the indicator body touching it) which gives a cosine error
> > IIRC. <rant>Its a PITA to add another shim, as you have to dismantle
> > the thing, and then recenter it so you can take a hi/low reading. Im
> > sure Ill get quicker, but it took 2 hours last night to get this
> > close.....</rant>
> > Are feeler gauges ok to use as the final shim solution? I seem to
> have
> > inherited about 3 or 4 sets, so have spares.
> > cheers
> > Dave
>
> Not familiar with the L5 tailstock construction, but when doing a
> similar job on my Colchester Master 2500, I started with feeler gauges
> to set it to where it should be, then cut custom flat shim from
> shimstock to give a larger surface area.
>
> AWEM
The L5 tailstock spilts into 2 just above the ways plate (for want of
a better description), and the top casting sits on the bottom,the top
one is machined flat, and the other has a 1/4" rasied machined bit.
There is a L-R raised machined rib to guide the offsetting, and the
screw bear on this. So 2 pieces of shim would work admirably once I
figure out the correct thickness, and there is some space for a bit of
glue to stop them shifting as well :)
Dave
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Posted by Dave Baker on March 1, 2008, 5:43 pm
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> evening all,
> whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
> noticed my tailstock is low, by about 8 to 10 thou. Is there an
> accepted way to shim this up? I have currently got 8 thou of feeler
> gauges in both ends, but its not quite perfect (by indicating inside
> the MT on the ram). unfortunately Im not sure exactly how much its off
> due to the bentness of the indicator pin (bent up to contact the taper
> without the indicator body touching it) which gives a cosine error
> IIRC. <rant>Its a PITA to add another shim, as you have to dismantle
> the thing, and then recenter it so you can take a hi/low reading. Im
> sure Ill get quicker, but it took 2 hours last night to get this
> close.....</rant>
> Are feeler gauges ok to use as the final shim solution? I seem to have
> inherited about 3 or 4 sets, so have spares.
> cheers
> Dave
An easier way to measure the height error is to fit a chuck to the
tailstock, hold two bits of the same size bar in both headstock and
tailstock then run a dial guage over the top of them. I use bits of 3/8"
silver steel of which I have plenty knocking about. Obviously both chucks
have to be true but you can check the tailstock one easily by taking it out
and fitting it back after turning it 180 degrees.
--
Dave Baker
Puma Race Engines
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Posted by dave sanderson on March 2, 2008, 3:37 pm
Please log in for more thread options >
>
>
>
> > evening all,
> > whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
> > noticed my tailstock is low, by about 8 to 10 thou. Is there an
> > accepted way to shim this up? I have currently got 8 thou of feeler
> > gauges in both ends, but its not quite perfect (by indicating inside
> > the MT on the ram). unfortunately Im not sure exactly how much its off
> > due to the bentness of the indicator pin (bent up to contact the taper
> > without the indicator body touching it) which gives a cosine error
> > IIRC. <rant>Its a PITA to add another shim, as you have to dismantle
> > the thing, and then recenter it so you can take a hi/low reading. Im
> > sure Ill get quicker, but it took 2 hours last night to get this
> > close.....</rant>
> > Are feeler gauges ok to use as the final shim solution? I seem to have
> > inherited about 3 or 4 sets, so have spares.
> > cheers
> > Dave
>
> An easier way to measure the height error is to fit a chuck to the
> tailstock, hold two bits of the same size bar in both headstock and
> tailstock then run a dial guage over the top of them. I use bits of 3/8"
> silver steel of which I have plenty knocking about. Obviously both chucks
> have to be true but you can check the tailstock one easily by taking it out
> and fitting it back after turning it 180 degrees.
> --
> Dave Baker
> Puma Race Engines
Hmm, I see that would be easier, and It is the tailstock chuck I
mostly need
on center for drilling anyway, Ill give it a go. :)
Dave
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> whilst doing some tiny (1 - 2mm dia) work on my hulking great L5 I
> noticed my tailstock is low, by about 8 to 10 thou. Is there an
> accepted way to shim this up? I have currently got 8 thou of feeler
> gauges in both ends, but its not quite perfect (by indicating inside
> the MT on the ram). unfortunately Im not sure exactly how much its