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Author Topic: Bridgeport Knee Mill Conversion?  (Read 269152 times)

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Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #770 on: June 09, 2018, 01:21:04 PM »
Sorry, not enough info

The error with the index was in the Z axis only

The positioning error was in XYC axes

Somehow something changed - i have my setter position stored in the screenset, it has worked well up to today when it was off by a few MM in three axes.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #771 on: June 10, 2018, 03:30:20 AM »
Another issue,

I am trying to work a part that needs both sides machining, flipping on X axis, Y is against the fixed vise jaw.

Y alignment is perfect but X is shifted +0.5mm on the reverse side so the front and back have a step.

I have tried two probes for X ref - electronic and mechanical, same result so it's not the probe or any macro.

The code seems perfect - i simplified it to just two points, the front was perfect and the rear was shifted, the code is easy to read - front X40 rear X-40.

I was previously flipping Y axis and the fault moved to the Y plane instead.

It seems I cannot work one side in X+ and the reverse in X- or Y+ and Y-

Any ideas, this machine is doing my head in, its all pointing towards controller or Mach3 now.

I have one more test to run today but I'm not holding much hope.

All previous work was one sided so no issue.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #772 on: June 10, 2018, 05:52:41 AM »
Finished my last test and it just muddies the water more:(


Made a part with two 20mm through bores at known XY offsets, I chose 35mm Y and 25mm X offset.


Without removing the part I then set my XY ref on the centre of the lower left bore and probed the upper right bore for its offset to verify the work,

The offset was verified on the DRO’s as 24.964mm X and 34.997mm Y, pretty accurate i thought


Next, I flipped the part as before, set my XY ref on one bore and probed the other, result was 24.970mm X and 34.984mm Y - still good.

I then set my XY ref on the other bore and probed the first one, result was 24.972mm X and 34.981mm Y - still good.

This tells me i should be able to machine two sides if i use a through-bore as a ref ?

But what i don’t understand is why i can't use the edge as ra ef when all logic says I should?

Probing the holes as above means the machine was in X+ and X- quadrants so is pretty realistic to the work.

I tried both mechanical and electronic probes and got results so similar that the difference is irrelevant to my work so will stick with my electronic probe.

Any thoughts?

Offline TPS

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Re: Bridgeport Knee Mill Conversion?
« Reply #773 on: June 10, 2018, 12:05:08 PM »
only possibilty witch is left, that your x- probe Routine is not ok, or?
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #774 on: June 10, 2018, 01:21:25 PM »
I thought that too, but,,,

There is now a possibility that my head is off-tram despite my thinking otherwise.

I am going to go through it tomorrow and verify before any further testing as it would explain a lot.

Offline TPS

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Re: Bridgeport Knee Mill Conversion?
« Reply #775 on: June 11, 2018, 01:42:06 AM »
you can also post your code, if you want.

sometimes 4 eyes see more than 2. ;)
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #776 on: June 11, 2018, 02:15:08 AM »
Thanks TPS but i proved the code was ok by just making a part with two points - one on each side.

That makes it simple to read and it still came out shifted on the mill.

Will know more once i have checked it over again.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #777 on: June 11, 2018, 01:28:15 PM »
Well,,,,

If fixing what i found tonight does not do the job then i’m packing my bags and giving up!

I tested the head tram and it was out about as much as it could have been out!

Badly off in BOTH axes by a frighteningly big amount, more in the X but both very bad, I’ve never had the nod move before, usually just the rotation.

Whatever happened when that cutter loaded up was far more severe than i thought, odd that it failed to break but just have smacked the head a fair bit.

It's back on now and i have cut a customers one-sided job ok, I won’t know about the two-sided issue until Wednesday as jobs piled up again :)

I can’t believe that fixing this issue would not fix the job, fingers crossed.
Re: Bridgeport Knee Mill Conversion?
« Reply #778 on: June 11, 2018, 04:47:46 PM »
Dave

Are you tightening those tramming bolts to 50lbft? I used to find that the head was easily knocked out of tram when I just tightened the bolts to what felt reasonable. I was surprised when I used a torque wrench just how much tighter 50lbft was, and I always torque them now.

Allan

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #779 on: June 12, 2018, 02:07:58 AM »
I never knew there was a torque figure!

I have a 10" spanner and just lean on that as hard as i can.

I do have a torque wrench so i'll check tonight.