The
following information was gathered during the construction of the Gold King 5-Stamp
Mill stamp guides.
I
have already completed an article #42 on “Types of Stamp Mill Guides” used on
the stamp mill. There are two styles, a wood style and steel with variations of
each guide.
Stamp
Mill “as found” condition. You can see the mill needed all new wood from the
pictures below:
GOLD KING VISITS
The picture below shows the Gold King
5-Stamp Mill in Jerome, AZ that is being restored. We had to use all new
timbers including guides.
Determining
Guide Spacing The
original guides could not be saved and we only had parts of the guides left.
This meant that we had to start from scratch to build the guides. The first
thing we did was to take measurements of the spacing on the cams. We found that
the spacing was not the same for all of the cams so we had to custom fabricate
the guides.
Guide
Templates The next
thing we did was to make a template of the guide hole spacings from the above
measurements. I used (2) 2” X4” X 53” with a piece of molding strip to make it
the same thickness as the 3X12’s. I cut two sizes, 2 7/8” guide holes and 3”
for the test stamp. The picture below shows the pieces that will be separated
and the “test guide fit.”
Verifying
Templates We went to
Gold King and installed the “test” guides and the “test” stamp to ensure that
we have the proper spacing for the stamps. The pictures below show the fit-up
of the test stamp to the test guides. The results were satisfactory!
The
critical measurements above is the spacing between the test stamp and the cam
lobe. We are looking for about ¼” to 3/8”
PHOENIX
WORK ACTIVITIES
Purchased Guide Lumber We brought the “test”
guides back to Phoenix to fabricate the guides from the information at the Gold
King site. I ordered (2) 3” X 12” X 10’ Douglas Fir
timbers that came to $71.00 X 2 = $142 plus tax.
NOTE: From here on in we need to
double check all of the measurements associated with the guide timbers. If a
slight mistake is made it will make the guides unusable and will have to spend
another $142 plus tax to fix the mistake
Transcribe Dimensions We transcribed the measurements from the
test guide to the guide timbers below.
Marking the Guide Botling We placed the malleable washer “stars” on
the guides and marked their locaitons above. Care must be taken to make sure we
do not drill where the stamps will pass through the guides.
Drilling Guide Bolting The holes were drilled that will hold the
guides together and anchor them to the cross-members. The all thread was cut
small to “temporarily fasten together while drilling the anchor holes and the
stamp stems. The final all thread will be about 20” long to allow bolting
through the 6” guides and the 12” cross members.
Drilling Stamp Stem Holes with 6” bit This is a critical
activity. The 2 7/8” stamp stem holes MUST be drilled perfrecly straight and
perpendicular to the guide. If they are off slightly the stamps will not pass
through the 12” guides. The holes will be drilled in stages. The first stage we
will use the 2 7/8” X 6” forcner bit. We will be able to make (3) passes with
this bit. This will take us about 2/3 of the way through the 12” timber, about
8”. That is as far as you can use this bit arrangement.
Special Tools The picture below
shows the special tools needed to ensure that we have straight stamp stem
holes. The long needle nose pliers is probably the most used item in the tool
box. There is very little room between the drill bit and the drill shank when
you get towards the end of the drill travel. My last project I did not have
this item and it made the job long and painful.
Drilling Stamp Stem Holes with 12” bit Extension This drilling activity
is even more critical. The 18” extension makes the drilling activity more
sensitive to misalignment. For this activity we will need to check the drill
truness more frequently. We not only need to check the guide level, but also
the drill bit orientation. The further along we go with the drilling the more
sensitive the drill and the guide are affected by misalignment. The two pictures
below shows the use of the levels in the process. I was albe to drill the last
4” of guide with one pass of the drill extension.
Job
Complete The job took 36-man
hours for constructing guides for a 5-stamper. This does not include the
manhours for determining the guide configuration of about 20 Mhrs. This is the
fourth set of wood guides that I have completed. This includes help from Rick
Herrem. The single thing that helps is having a template for the guides. You
add much more time, as in the case with the Gold King guides, to do the job if
you have to start from scratch. The picture below shows the sawdust that I
generated drilling the (10) holes into the two guides. The 30-gallon trash can
is about ¾ full of sawdust
Finished
Product The picture
below shows the finished guides with their markings.
Installation All we have to do now is to install the
guides on the Gold King 5-Stamp Mill. I hope they fit!
