I bought the 6" Ridgid jointer the other day. Upon assembly I have
found that the infeed table is convex across the 6" width (the center
is about 0.0025" higher than the edges). The outfeed table is concave
(the center is about 0.0035" lower than the edges). The net result is
that, for example, if the tables are set at the same height at the
center, the edges of the infeed table will be about 0.006" lower than
the outfeed table. This distortion does not extend the full length of
the tabls as they are perfectly flat towards the ends.
Is this sort of distortion normal? Is it within acceptable tolerance?
Should I be returning it to HD and demanding a replacement.
Thanks,
Dave
How did you measure that the 0.0025 and the other measurements?
Whatever you used must be a lot more accurate that that. Starrett
straight edges are 0.0001 accurate per foot of length. Many others are
0.001 (one less zero).
DaveH wrote:
> I bought the 6" Ridgid jointer the other day. Upon assembly I have
> found that the infeed table is convex across the 6" width (the center
> is about 0.0025" higher than the edges). The outfeed table is concave
> (the center is about 0.0035" lower than the edges). The net result is
> that, for example, if the tables are set at the same height at the
> center, the edges of the infeed table will be about 0.006" lower than
> the outfeed table. This distortion does not extend the full length of
> the tabls as they are perfectly flat towards the ends.
>
> Is this sort of distortion normal? Is it within acceptable tolerance?
> Should I be returning it to HD and demanding a replacement.
>
> Thanks,
>
> Dave
"Never Enough Money" <[email protected]> wrote in message news:<[email protected]>...
> How did you measure that the 0.0025 and the other measurements?
> Whatever you used must be a lot more accurate that that. Starrett
> straight edges are 0.0001 accurate per foot of length. Many others are
> 0.001 (one less zero).
With a 6" staight edge that I verified as straight along the length of
the tables at various points. I then placed this straight edge across
the width of the outfeed, immediately after the cutter, and could see
visible light under the centre. I measured this to be 0.0035" with a
feeler. The same straight edge placed across the width of the infeed,
just before the cutter, rocked. Using a dial indicator and stand I set
the tables level at the fence side of the cutter. In the centre of the
cutter I measured a 0.007" height difference and at the other end a
0.002" difference.
Now I realise that my technique and instuments may not be ideal which
is why I qualified my original measurments with the word about. I
didn't, however, expect to be able to measure ANY distortion in the
tables.
replying to DaveH, Daniel Marks wrote:
I have been a machinist and also have been in Quality in machine shops most of
my life (I am old BTW), While I cannot find the acceptable specification
generally across flatness within .003 inches will not affect the flatness or
squareness of the product produced on your jointer. I would believe that .003
or less would be considered within specification at the factory as well. That
really is pretty flat for a ground surface. It is not aviation quality
perhaps, but fine for making great flat and square boards.
--
for full context, visit https://www.homeownershub.com/woodworking/jointer-table-flatness-331193-.htm
On Friday, November 29, 2019 at 12:14:05 PM UTC-5, Daniel Marks wrote:
> replying to DaveH, Daniel Marks wrote:
> I have been a machinist and also have been in Quality in machine shops most of
> my life (I am old BTW), While I cannot find the acceptable specification
> generally across flatness within .003 inches will not affect the flatness or
> squareness of the product produced on your jointer. I would believe that .003
> or less would be considered within specification at the factory as well. That
> really is pretty flat for a ground surface. It is not aviation quality
> perhaps, but fine for making great flat and square boards.
>
>
> --
> for full context, visit https://www.homeownershub.com/woodworking/jointer-table-flatness-331193-.htm
"Pity the woodworker that ought to have been a machinist"
- Someone
"DaveH" <[email protected]> wrote in message
news:[email protected]...
> I bought the 6" Ridgid jointer the other day. Upon assembly I have
> found that the infeed table is convex across the 6" width (the center
> is about 0.0025" higher than the edges). The outfeed table is concave
> (the center is about 0.0035" lower than the edges). The net result is
> that, for example, if the tables are set at the same height at the
> center, the edges of the infeed table will be about 0.006" lower than
> the outfeed table. This distortion does not extend the full length of
> the tabls as they are perfectly flat towards the ends.
>
> Is this sort of distortion normal? Is it within acceptable tolerance?
> Should I be returning it to HD and demanding a replacement.
>
The board is entirely different after it passes over the cutterhead, so the
in/out differences you noted are differences which make no difference. The
concavity in the out _might_ give a bit of snipe. Run a few pieces and see.