Thread: Kondia Turret Mill - Knee Clamps

I am cleaning up this mill and re-commissioning it with CNC (so far got steppers rotating on the floor).
Currently the knee gib is out and I am trying to clean the various knee mating surfaces.

There are two typical hand-operated gib clamps on the LHS of the knee ways.

The clamps are M10 thread with the typical 'pull-to-reposition' handles.
When the clamp is removed from the knee, left in the hole is a plunger pushed by the screw to apply the force to the gib.
The gib has no machined recesses to accept the end of the plunger.
So the plunger probably has an angled head to match the dovetail angle.

How can I get the plunger out ?
Once out, how does one re-position with the angles matching ?

Tried applying a flexible soft tube and mouth sucking without any joy.
Ran some compressed air through the now vacant gib gap, and simply moved the plunger further into the gap !
Coaxed it back with a 300 mm rule from the bottom.

My next attempt will be a small magnet on a stick, which may not work if the item is non-magnetic.
And I have an industrial vacuum pump (that needs some minor work to get going).

I can see the top plunger down the hole.
It has no tapped hole, has a bright finish and no sign of bruising from the M10 screw.

Any suggestions ?
John

Hi there,

They normally fall out when the knee or saddle (there should be a few in the saddle too) are disassembled. To get them out if it's still on the column, try a dab of superglue on the end of a match stick to se e if you can stick it to the slug.

That "slug" (for want of a better term) will have an angle on the inner facing end to match the Gibb strip.

Simon

Sent from my SM-G970F using Tapatalk

Try a drop of super glue on the end of a wooden skewer.
Cheers,
Greg.

Why not leave them there.
If you believe you must remove and inspect , how deep are the holes?
After doing your calcs how much do they need to move before protruding out of there captivated positions?
Have you been able to calculate the amount of friction you may need to overcome to get these clamp pins to move?
Have you assessed a chemical analysis of what might be causing the friction/suction of these small diameter clamping plugs.
Have you purchased a suitable chemical to release these clamping plugs from there prolonged captivity.
Why didn't you remove and clean and inspect whilst the machine was undergoing this retrofit?

This is my knee on and off the mill. I don't remember anything difficult about removing the locking things. The right picture shows the knee on the mill with the locking handles removed. You are right, the thing that pushes on the gib is angled. its self aligning really, just push and it will turn to the correct angle. I'm pretty sure i would just have stuck a magnet I have from a microwave, onto the side of a PO6 screwdriver (a long screwdriver) and shoved the screwdriver point into the hole. That channels the magnetism down the screwdriver and makes it easy to pull things out a hole. Usually leave the screwdriver a bit magnetic which is a pain but you can get rid of that easy enough. There were quite a few things that I took a long time to figure out how to dismantle on this mill, but getting those out must have been easy because I have no pictures of it.
20170122_110453.jpg

I tried the magnetic thing this morning and the plunger didn't move a fraction. My memory isn't good but maybe now I sort of remember the plunger looking like this
ScreenShot368.jpg
And I think it might have been stainless so not magnetic. I must have left it in until the knee was off, but the miracle is I remembered to put it back in.

If you weren't thinking of taking the knee off, have a look at these pictures to see if it changes your mind
This one shows how many chips were inside the knee. That beveled gear has a cover but it was still running in a mix of grease and metal.
20161227_151811.jpg
You can see the chips were heaped up in a pile waiting to top up the existing grinding mix for the slideways between the knee and the mill
20161227_162707.jpg
And the Z axis also has a cover but it still got covered in grinding paste.
20161227_161917.jpg
And mine was a nice clean looking one. Thats still the original paint, i never bothered to touch it up.
20170624_155155.jpg

pipeclay,
This is only a re-commission, not a re-build, so removing the knee was never on the plan.

Removing the clamp plungers is only part of a general clean, check, modify/correct as necessary, lubricate and re-assemble process.
The area around the knee gib seems in good condition, plenty of oil residues.
The clamp plungers slide when pushed, so no real need to remove them.

sossity,
Great photo, thanks.
It never occurred to me that the horizontal approach of the shaft from the front handle clamp would penetrate the slide surface, obvious when you think about it.

On my mill, removing the knee gib did not allow the knee to separate from the column.
I thought it might, sort of, balance on the screwjack.
The saddle and table are not mounted, and I have a gas-spring outboard from the screwjack, this may have the CofG closer to the column.
I have a section drawing of the screwjack, I will check it to see if that is what holds it square and firm.
Forcing it is not an option, the slideways appear to be in Ok shape and adequately lubricated.

My prime interest in this area is to check the new lubrication system, flexible lines from a distributor with individual meters next to the pump.
It appears almost impossible to check the oil delivery ports to the slideways without removing the knee.
I guess I will re-assemble and test with vertical movements and check for delivery of oil on the exposed slideways after the knee moves away.

My personal timeline is to have the knee moving under CNC control for 3Dec19.
John

sossity,
You posted while I was writing !

More great photos.
I had good access to the knee interior and cleaned out aluminium swarf, not as much as yours.
The mill had been used to make racing motor-bike parts out of aluminium alloy.

The spaces between the knee and the column were also relatively clean.
My bevel gear is covered, not too dirty, cleaned, greased and cover replaced.

The original Y-axis slideplates did not fit at all well, a casualty of the CNC modifications.
I made new close fitting slideplates so that a minimum of swarf will penetrate in future.

John.

Mine was the same as you and I had to remove the knee by lifting it off the top of the wayslides. Mine had not been getting oiled and I put a lot of effort into checking all the oilines.

I can confirm the only metering units are the external ones where the oillines come out the knee and then back in to feed those slideways. For anyone not familiar with this mill, there is a metering unit on each side feeding the slideways. You can see one here on the left side at the top with the white ptfe tape.
20170604_091713.jpg

On the previous picture showing the chips inside the knee, you can see there is a splitter for the oil at the front side that mates to the mill. I took everything apart and all the oil lines were ok, so I'd guess you will get away with just checking/changing the external metering units for the knee. There were no metering units on that internal splitter, it was just open oilways. When assembling, I added one metering unit at a time and blocked the open oil line so I could check that oil was coming out each individual metering unit as i went along. It works great now. I wasn't able to reuse any of the metering units and most had been hollowed out anyway, meaning the few that remained were passing no oil.
20170608_092914.jpg

For the lubrication. I scrapped the entire distribution system, meters, pipes and joints.
Purchased an entire system with flexible lines and another pump.
One pump for slideway oil and one for the ballscrews.

The two pumps are on a outrigger bracket on the LHS, approximately where yours is depicted in the photos.
On the outrigger are two distribution headers with a separate meter for each line.
I know flexible lines are vulnerable, but this is a hobby machine in a personal shop.

Advice elsewhere suggests the meters should be close to the application point.
Not sure if this is critical, time will tell.
At least with my arrangement, checking is much easier.

Photos will be posted once I get the lubrication system installed and commissioned.
John

You Kondia looks very similar to my pacific. Is kondia made in Spain by any chance?

Simon

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Kondia was spanish. Clausing-Kondia was sold in USA I think though, but they were Kondia made mills. Now Kondia is kaput and Clausing have purchased the right to make the original Kondia mill. I asked them how much for a backgear but it was way to expensive for me, like $600. i saw on forums, that Kondia itself was fairly cheap for spares, when they still existed.