Hi Group:

Well, the saga of my "new" Burke Millrite mill continues. You may remember
my post of my stupid mistake of raising the knee so high the elevating
screw slipped out of the knee "nut". I just wanted to clean the gibs.....

Bob May had some very good suggestions to loosen the knee gibs and let the
knee "drop" back into the nut. Good idea, except (as I found out) the nut
was so full of crud that the screw would not re-engage the threads.

What finally worked was to loosen the gibs per Bob, and jack up the knee
itself with a floor jack and 2x4 to raise the knee/elevating screw
COMPLETELY out of the nut.

I scraped/cleaned the crud out of the threads in the nut, added lots of way
oil, lowered the jack to drop the knee and viola... a working knee!!

I found tramming the head in X direction to be no problem.. Easy to adjust
by tapping the head. I have less than .0015 difference when rotating the
spindle left and right.

However, this is a fixed head unit and in the Y direction, I have .006
difference between the front and back.

I see no way to adjust the head front to back, so I am assuming I have to
adjust the knee gibs to get the table adjusted to the head. Yes??? or no?
After an hour of adjusting the knee gibs, I am still no closer than .006
front/back. So, maybe adusting the knee gibs is NOT the way to go.

I am using a .0005 indiator mounted in a 3/4 rod/collet swinging a radius of
about 5". I am swinging the indicator over a set of matched 123 blocks to
avoid running the indicator over the table slots.

Thanks for any ideas.

Steve Koschmann

Steve
I havn't actually seen one of these machines, but if its the one on
this page - http://www.lathes.co.uk/millrite/
First- Have you checked the flatness of the table itself? Lock the
knee and the x-axis(with the table in the center) and using a 1-2-3
block or a long parallel move the table from front to back and indicate
the table top.
Next, with the table to the front, set the indicator and release the
knee clamps. If you get any movement then the gibs need to be adjusted.
Repeat this after adjustment, if you still have a discrepency in the
front to back readins then you will have to look at the surface between
the head and the ram. Another quick check would be to lower the quill
and place an indictor on the front of the quill and raise or lower the
table it see if there is any misalignment there, this should tell you if
the head if off.
Then you may have to shim the face of the head where it attaches to
the ram. Although you may want to take it off and check the surfaces for
wear first. Maybe time to brush up on scraping techniques :-)


Steve Koschmann wrote:

Hi Group:

Well, the saga of my "new" Burke Millrite mill continues. You may remember
my post of my stupid mistake of raising the knee so high the elevating
screw slipped out of the knee "nut". I just wanted to clean the gibs.....

Bob May had some very good suggestions to loosen the knee gibs and let the
knee "drop" back into the nut. Good idea, except (as I found out) the nut
was so full of crud that the screw would not re-engage the threads.

What finally worked was to loosen the gibs per Bob, and jack up the knee
itself with a floor jack and 2x4 to raise the knee/elevating screw
COMPLETELY out of the nut.

I scraped/cleaned the crud out of the threads in the nut, added lots of way
oil, lowered the jack to drop the knee and viola... a working knee!!

I found tramming the head in X direction to be no problem.. Easy to adjust
by tapping the head. I have less than .0015 difference when rotating the
spindle left and right.

However, this is a fixed head unit and in the Y direction, I have .006
difference between the front and back.

I see no way to adjust the head front to back, so I am assuming I have to
adjust the knee gibs to get the table adjusted to the head. Yes??? or no?
After an hour of adjusting the knee gibs, I am still no closer than .006
front/back. So, maybe adusting the knee gibs is NOT the way to go.

I am using a .0005 indiator mounted in a 3/4 rod/collet swinging a radius of
about 5". I am swinging the indicator over a set of matched 123 blocks to
avoid running the indicator over the table slots.

Thanks for any ideas.

Steve Koschmann





--
--------------------------------------------------------------------------

James P Crombie

Summerside Machinist
Prince Edward Island Amateur Astronomer
Canada 3D Designer

E-mail
Astronomy webpage http://www.jamescrombie.com
Rhinoceros 3D webpage http://www.jamescrombie.com/rhino/
Mirror Grinder page http://www.jamescrombie.com/pics/
--------------------------------------------------------------------------