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Author Topic: Bridgeport Knee Mill Conversion?  (Read 269116 times)

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Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #760 on: April 23, 2018, 02:45:15 PM »
Total bend was 1.2mm so pretty bad.

Using my press and some patience, I now have it down to 0.04mm which i think is far enough.

Going to remove the back-gear as well as it gets hot at full speed and makes a racket too, not been used since going CNC anyway.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #761 on: April 24, 2018, 03:19:08 PM »
All back together, runs smoother now and a bit quieter without the back-gear belt.

:)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #762 on: April 28, 2018, 11:24:32 AM »
The tool path display - is there a reason the path is so small compared to my display???



The material is only 5mm beyond the path shown.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #763 on: May 04, 2018, 02:56:35 AM »
Ooh, thats a way back, pretty certain its in this thread though.

I have an encoder, a basic linear way(nylon block in channel) the encoder connects to a 2.5mm pitch belt in a loop, along the loop is connected an angle bracket facing an R8 socket.

The encoder is connected to an ENC module for the CSMIO, Mach3 has a macropump macro that looks at the input from this encoder and displays it on my screen-set, real-time. The screen has a "Zero" button and a "Set" button. The angle is lowered onto the socket on the setter, zero is pressed and the tool fitted, angle is lowered onto the tool tip and "Set" is pressed - this copies the encoder DRO to the tool table and then shows the table so you can give it a name etc.

Takes seconds to do, you can load tools in the middle of code if you forgot one or break one etc. The actual "height" displayed is irrelevant, its in an R8 socket which always locates on a set part of the taper just as the spindle does, the Haimer probe i use for TOM setting is also measured and entered - all my work is relative to this "tool".

The only cost was for the ENC module, the rest is all junk-box bits. It was a fun project basically, but quite useful.

Update -

Tool setter has now been shelved.

I have been chasing an odd error that manifests itself as cutters ploughing into my sub-table for no known reason by anywhere from 0.1mm to 0.5mm seemingly at random. After a LOT of testing and help from a friend, it boiled down to the fact that the tool setter i built was not accurate in all positions so the error varied with tool length.

It took many hours of testing with various styles of material top and tool length sensing but the results finally pointed to the setter outputting garbage and garbage in = garbage out as always. The most accurate method was to use the Z axis for tool measurement and tool table loading.

I have got some parts on way to mess about with but also ordered a bed-mounted tool setter that connects to my probe input so i can get back to automated TLO measurements - the price makes DIY pointless really but its from China so won't be here until next week. Supposed to have an accuracy of 0.001mm but i'll take that with a pinch of salt until i test it ;)

A lot of grief was given over this saga, my sub-table now needs resurfacing, the mill was pulled apart, code was checked :( and all attributed to lack of accuracy on the setter - the lesson learnt is that if you are telling a machine something is 50.023mm long then it better damn well be 50.023mm long ;) ;)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #764 on: May 04, 2018, 03:00:50 AM »
The tool path display - is there a reason the path is so small compared to my display???



The material is only 5mm beyond the path shown.

Yes - the reason is that the tool path display is designed to be square :)

Simple fix = zoom in before running.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #765 on: May 05, 2018, 09:27:29 AM »
Impressed myself today.

While waiting for my tool setter to arrive, I built one from bits - 8mm ground shaft, linear bearing, scraps, odd switch from junk box.



Ok, she's ugly - i wasted no effort on aesthetics, no aerospace grade aluminium was cut and its wired up with croc-clips :)

BUT...

This little bugger has an accuracy of 0.005mm - thats less than 2 tenths of a thou anywhere on the plate surface thanks to the linear support bearing :)

The switch is nothing special, a China import V3 micro with roller lever.

I'll probably end up using the bought one when it comes but shows what can be done with junk.

Hopefully get some time Monday to test it on real tooling and a small job.

:)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #766 on: May 10, 2018, 01:02:05 PM »
Got the real height-setter mounted today.

All works nicely, my screen-set now sports a page for tool-setting with table/knee positions, speeds etc

Using CS-Labs M31 probing code.

Job done:)

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #767 on: May 13, 2018, 09:05:18 AM »
The new setter in action, simple and fast :)

Uses CS-Labs M31 coding.

https://youtu.be/YzV89lxtjcA

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #768 on: June 09, 2018, 07:02:34 AM »
Mill strikes again :(


Ref all axes and the z fails with encoder too far from index pulse - it has done this before and it's an easy fix, just flip the belt round one step on the pulley and re-ref = all ok.

Went to set new tooling for a job, tell it to go to my tool setter position and find it's about 5mm out in X and 3mm in Y, Z is always Zero/home so that can't be out.

So, i re-homed and it did exactly the same thing, with no other option i reset the the setter ref positions and carried on.

Now, with a little red alarm going off in my head, I thought to check my master height probe position - easy to do as it is always tool 100 so i just set it as tool 99 so i can compare the two positions in the table.

Sure enough it was 3mm off!

So that is X/Y/C axes ALL lost or changed their home/ref position??

No switches have been moved so now i can't trust the machine again.


It's getting worrying now as i have started to use it more and more but yet again I find I can't trust or rely on her :( :(


Anyone have any ideas on what can cause this - don't forget this is a servo machine with CSMIO-IP/a controller and Mach3.

Thanks

Offline TPS

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Re: Bridgeport Knee Mill Conversion?
« Reply #769 on: June 09, 2018, 12:40:54 PM »
ok you are doing a Referenz on index pulse.

means the ref Limit Switch is very secondary.

reference on index pulse means go t reference Switch reverse direction and look for the next Zero pulse of Encoder.

Quote
it has done this before and it's an easy fix, just flip the belt round one step on the pulley and re-ref = all ok.

this teels me that you have a seperate Encoder for Feedback Loop, witch is belt driven.

ok if you shift this belt for one step, it is "normal" that yor home pos shifts as well (index pulse !!)

Thomas
anything is possible, just try to do it.
if you find some mistakes, in my bad bavarian english,they are yours.