Modifying the i1i0 table for the i1pro2

The X-Rite i1pro 2 is backwards compatible in most ways with the original i1pro spectrometer,
with the basic dimensions, aperture hardware, and driver being very compatible. One area where
it is subtly different is in working with existing i1i0 tables. The body of the i1pro2 is a little
lower, the foot is continuous rather than having a gap, the sides are straighter, and the head a little
larger in diameter. Given the form fitting cradle in the i1i0, the end result is that the i1pro2 won't
fit into an existing i1i0.

X-Rite has a scheme to allow existing i1i0's to be upgraded: <http://www.xrite.com/product_overview.aspx?ID=1959>,
but for some of us not in North America, or who have not paid the local distributor an outrageous price margin
for the privilege of buying it via them, this is not such an attractive proposition.

Since It seems to be a simple mechanical issue, I thought I'd see about modifying an existing i1i0 to solve this problem.
What follows is the result.

WARNING: This is not for the feint of heart. If you are not the sort of person who has the experience
and confidence in your ability to carry out changes that involve carving away parts of an expensive piece
of kit and returning it to working order, don't attempt to emulate what follows. Read it for entertainment
value only. It will void you warranty. You have been warned!

Removal

The first step is to remove the transparent foot. First detach the arm from the main plate in the usual way,
and turn it over. Next remove the grey half-circle cover plate - there is a small opening at the peak of the
circle to release the clip, or you could gently lever it from from the ends. Next step is release the foot from its main
pivots, being careful not to tug it too far, since there is a cable attached, and watch out for the counter-weight
rod and spring. The last step is to release the plug and cable, but this needs to be done carefully so as not
to put too much tension on the spring, or you will break it's anchor point (I found this out the hard way).
With the tension released, the spring can be detached from the foot.

The foot is in two pieces, an upper and lower, and is joined in three places, two hooks at the rear,
and an internal molded clip at the front. You probably want to remove the glide and its metal  retaining clip, the clip
needing the small spring unwound in order to release it. The internal molded clip is very hard to release, even though
you can get to it from the inside. It needs to be pushed outwards, but since it is going to be discarded anyway,
the best approach is probably to work it until it snaps off internally. This is because the two pieces are
going to have to be fitted together many times, and the clip will no longer a practical fastener.

Destruction



The bottom plate needs some subtle but careful modifications. One is to extend the two depressions at the
heel of the instrument so that they join. (see "A") It doesn't have to be exactly the same level, but within
a 0.1 mm or so of it. One approach would be to use a drill stand that can be locked off in combination with
a small milling or cutting tool. The tool can be held at a fixed spacing while the plate is slid one way and the other.
You want to avoid touching the existing depression surfaces, as they establish the instrument level.

I used a high speed hand held rotary tool, and a variety of attachments (such as a small
cutter, larger cutter, cutting wheel etc.) to perform the modifications to the foot.

There are thee clips on the bottom plate that hold the aperture ring in position, and two of them
need a slight modification. (The official X-Rite i1pro2 foot seems to have a more sophisticated
locking arrangement than this.) The one at the 5 O'clock position needs the sloping guide on the top of
it removing completely (see "B"), while the one at the 9 O'clock position needs it half
removing (see "C"). This is to allow for the body of the instrument having less clearance
in these areas. The cut-out for the visual location guide also needs shaving slightly, to accommodate the
lower body of the instrument (see "D"), and laying the instrument into position will act as a guide as
to how much to remove, and making sure that the instrument now clips properly into position.



The upper plate needs much more extensive modifications.The half circle at the head end needs
expanding in radius by 2-3mm (see "F"), while the heel needs carving away to join the two wells
allowed for the i1pro foot. (see "G") Two straight cuts are needed from the heel half circle to the
head half circle (see H). A great deal of ribbing will be cut away, and the cut-out for the location
guide will become completely detached (the connection remaining in the above photo is a new
bridging rib - see below). Once again, the instrument can be used as a guide
as to how much to carve away. You're done when you can clip the instrument into
the combined upper and lower plates, with a minimal amount of extra clearance or slop around it.

Reconstruction



The upper plate will have been severely weakened in this whole process, and now needs
strengthening. I cut two new ribs out of a piece of 2.5mm thick clear acrylic, both
120 mm long and 12mm wide tapering to 10mm. One needs a cut-out to allow
for a molding bump (see "I" below), and the other needs thinning to 5mm where it crosses
the location guide cut-out (see "J"). Some finessing is also needed where they sit beside
the remaining main ribs at the foot. There is about a 10mm overlap that will be glued and
used to project the foot support out to the top plate. Room needs to be cleared
for these new ribs along their length, and the plastic prepared for gluing by
roughening the surfaces where they will be making contact.
I cut down and shaped a 2.5mm threaded plastic spacer for the bottom plate (see "E"
in the first photo), to use with a matching countersunk screw in the top plate to take the place
of the original molded internal clip that fastens the two plates together.
It's important to make sure that everything fits together again, before moving to the next step
of gluing the new pieces into the top plate.



The new ribs are glued into place using a two part clear epoxy glue, laying it upside-down to do this,
so that the bottom plate can be used to align the separated pieces around the location guide. The 10mm
glued overlap at the heel is important in returning strength to the top plate.

Re-assembly is the reverse of the disassemble.

You can then double check that the i1pro2 clips into the modified i1i0.

The completed modifications, ready for testing.



Hopefully you've found this article informative and/or entertaining.

Graeme Gill.