Bridgeport Interact 4 Series 2 to Acorn6 build

[richardb15]

The booster is a 25:1 type 2620 from Spencer Franklin, max 100psi inlet so that is 2500psi on the hydraulic side, or 2psi as-is it seems. I can tell how old it is because London stopped using those area codes decades ago!:



After much cleaning:


So it turned out the rod seal that should have been in the groove was missing, just totally turned to dust and gone into the oil:


You can still get seal kits for these believe it or not but only in the UK and £80 a set. I figured I'd just head down to the local hydraulic place, get seals that are close and modify as required. The nearest rod seal was 1mm too tall but correct ID/OD, and the top seal backing ring was 2mm over on the OD so a bit of machining sorted those and back together all for $35, that was a win







With everything reassembled it was time to test it. You can see the drawbar hyd cylinder here on the very top. I've set the drawbar to move 10mm, that is limited by the round ring, and here you can also see the prox sensor for toolchanges, this disengages the booster solenoid if the spindle is below Z0 so it can't accidentally release the tool. The arm at the end is also powered by the hydraulics, that moves a dog into one of the Z ballscrew pulleys to stop the hydraulic force pushing the spindle down and causing a position error on the Z drive.



No excuses now..... time to try and run a programme I think

[richardb15]

So... first job! I need a new sprocket for a customer job as the original has worn teeth and the wrong offset, so I bought a blank with case hardened teeth:



Into the CNC lathe first to do the centre bore and hog off unnecessary weight:


Then turn the rear boss to the correct height:


Now to quickly do some CAD and a DXF then into CNC12 and Intercon to write the programme. I just use Onshape for quick jobs as you can just pick a surface, right click and export DXF, so easy


After that it's time to get busy on the mill, first job for it after the retrofit, day 1 of paying itself back!


Lots more work, tweaking, optimisation and tidying up to do, but great to have it capable of running jobs

[richardb15]

One thing I have not got right is the Mfunc6 macro. I hope someone can help here. I'm running CNC12 v5.24 and a pro licence.

I have used the router Mfunc6 file as a base from the tool setting options knowledge base thread here:
viewtopic.php?t=1493

Now, problems. That thread is locked, and most of the info in there is for CNC12 v4.x and for routers, and 6-7 years out of date. The info on toolsetting macros seems to be spread around various user manuals, threads, instruction guides, and mainly for routers with what I guess is a fixed part Z0 on the router bed (spoilboard?). With a mill the part Z0 needs to be altered for each job as they are all different heights.

I've got a fixed location tool touch off probe permanently wired (so no TT detect) and the touch off switch is connected to IN11. You can see this in the first minute of the YouTube video posted a couple of posts above this one.

I also have a KP-1 probe that is removable and that is IN9 for KP1 tripped, IN10 for KP1 detected.

Using the Mfunc6 macro I've attached here, with only mods from the original to account for the Acorn6 extra inputs and my IN config, I am selecting option1 when toolchanging, which should auto reset the Z0 based on the tool touching the TT. All my tool library H values are set to zero as well.

My expectation was that doing a tool touch off at each toolchange (sometimes I don't have enough toolholders so use collets, hence checking each change) would leave the part Z0 as-is, and adjust/overwrite the H value of the tool being checked and apply that. Instead I've had to set the part Z0 using the difference in height between my TT probe and the part Z0 which for this job was 29.9mm, as per parameter 71. But surely this isn't right as I'd have the change parameter 71 for every job instead of just probing the job with the KP1 and setting part Z0 then having the tooling sort itself out.

I'm sure I've read somewhere about using the Mfunc6 and a TT to rewrite tool H values but I can't find that info again. Can anyone help point me in the right direction to update/rewrite the Mfunc6 or share an existing one that works for a mill and TT?

[richardb15]

No thoughts from anyone on the tool length, TT and part Z zero stuff in the Mfunc6 as above?

My head is hurting from getting into all these macros, and it seems there are macros for macros and macros with several levels of embedded macros My tool touch off has a small air nozzle to blow chips off the touch surface so I installed a 24v solenoid into the air system and wired it into the relay board OUT9. I also set up a user adjustable air pressure switch as my knee (W axis) needs the air assist to move upwards, it just faults the drive out without the air on. So a couple of simple tasks.... add a check into the PLC to ensure air pressure is good, otherwise show a warning, and add a bit of code into the Mfunc6 macro so when probing a tool the air solenoid is turned on.

4 hours later The CNC12 user manual and the macro programming guide both seem to relate to Acorn with 8 outputs, and CNC12 v4.x, so I spent hours trying to work out how to use a line of code to turn on/off the air solenoid. Simple when you know how! The manuals cover how to do it for Outputs 1-8 (with M61-68 and M81-88) but M69 is return to machine zero, no nothing to do with Output9.

After going though the PLC source line by line and using Notepad++ to search for "airblownozzle" I realised that, tucked away on line 2243, was the clue I was looking for!
AirBlowNozzle_SV IS SV_M94_M95_36; (AirBlowNozzle)

After setting Output9 in the wizard to be the air blow nozzle function and rebooting it seems that an M94 (on) and M95 (off) for thingy 36 will do the job. A simple M94 /36 line into the Mfunc6 before the tool touch off section, and an M95 /36 after the tool touch off is completed is all that is needed. Easy when you know how.

I have the air pressure switch wired into Input5, inverted as the switch puts out +24v when it sees pressure and open circuit when no pressure. I used a 1K pull up resistor so the Acorn sees +24v on the input when air pressure is good, and 0v when no good. That logic is of course backwards for the input hence inverting the logic. The low air pressure message doesn't seem to appear all the time, shouldn't it be running as logic in the PLC code all the time? Report attached if anyone can advise, thanks!

[richardb15]

A couple of days off macros to do customer work and some serious shopping..... I want to set up an A and B rotary axis to complete the 6 axes capability. Buying a ready made 2 rotary setup is possible but used ones are hens teeth here, and new ones from China are around $15k, or from USA/Europe 2-3x that. I could buy harmonic drives, decent bearings and a bunch of steel and make my own from scratch but that would be a long process. Time for lateral thinking. A friend had spotted a 6 axis industrial robot on a clearance site for $300. I called the bloke up and he said he actually only wanted the motors and drives, not the rest of the machine. Well I only want the gearboxes and slewing bearings, so he took the motors off and gave me the rest for free!







The main body has one large bearing and gearbox in the base, and two gearboxes, one each side for the elbow joint. Realistically they are all too big for my build. However, the wrist joint is 2 axes all integral and has about 210deg movement on one axis and 360deg on the other:





All I have to do is transfer the gearbox pinions from the old motors to my spare Leadshine drives and make a sturdy mount for that wrist assembly to go onto my machine bed and I've got my A and B sorted I'll make a face plate to go onto the B axis so I can mount jobs or chucks onto that.

Whilst at it I also bought a couple more toolholders and a two point boring head for doing cast iron cylinders, AU$140 delivered, not worth making them for that. More jewelry for the wifes cabinet

[richardb15]

Been a while with an update, I've been deep into macros, auto tool lengths and probing but think I've finally sussed all that.

After doing a morning of recalibration and backlash I realised the X axis had way more backlash than was healthy (0.08mm) so I figured if I didn't sort that now, I'd struggle with thread milling so may as well take the pain and get into it.

My usual first port of call is to stick a DTI on the end of the ballscrew and see if the problem is the recirc ball nut, or the thrust bearings holding the ballscrew to the machine.



That video is taken looking up under the machine bed and I'm just using the WMPG to rock the leadscrew backwards and forwards a few tenths of a mm. That will be the culprit right there you can easily see the movement of the ballscrew relative to the machine bed.

Going to the other end of the X ballscrew there are the two back to back taper thrust Fafnir bearings. The preload and ballscrtew location is provided by a threaded collar, but looking at the chisel marks on it I'm not the first person to be in here!


I tightened up the nut but still checked the ballscrew was running free, then did the end float check again


Less than 0.02mm, that'll do

[richardb15]

For my two rotary axes I can get back to machining those now. I took the old motors apart, parted off the shafts that provide the lcoation and gear drives, bored them out a thou under 14mm then used the mill to machine pinch bolt holes.



They now fit very nicely onto the Leadshine motors



CAD has been done so I could sort out in my head how all this went together. The plan is to use the blue end mount plate as a face plate that will take centres, a chuck etc as required for work holding.


I also collected all the laser cut plates so I can now start machining the bolt holes, squaring them up etc

[richardb15]

I think I've also sorted out a suitable workflow for part Z height setting and auto tool length measurement in the M6 macro. The base macro I was using I think was written for a router where the Tool Touch was placed on the machine bed, and the stock material was on that so it used #159 (user variable that is retained on machine power off, material thickness) and #9071 (parameter 71, height of tool touch off). Those values by themselves don't really work with a mill where a lot of work is done in vices and fixtures well off the machine bed. Yes you can use a probe to measure from machine bed to work surface, but by having that distance travel capability in effect is wasted machining depth as it's only using for tool and Z0 work height. I also modified the messages to show the #159 and #9071 values as reminders.

My workflow around that was to make a stand for the TT to get the touch surface around the same height as the machine vice jaw top. I can then probe the distance from vice jaw height to TT, that is then used as P71 and doesn't change unless I break the setup, in which case its a single measurement to set for the new setup. I then probe or measure the height from vice top to my intended part Z0, use what was the material thickness (#159) and input that in the tool change M6 macro as it runs.

I figure I can do some further work to update the macro to do those measurements using the KP-1 automatically, but for now I have a workflow that works and I can use collet toolholders that sort out their own tool heights in a job so I don't need to be limited to tool count by just the toolholders I own.

[cnckeith]

cool, thanks for posting. great information.
and looks like you got the tiger by the tail with the robot!
suggest you buy/build a dedicated CNCPC that is not a laptop for the bridgeport
good cheap cncpc discussion thread is here.viewtopic.php?t=1914
nice resistive touch screen is here. https://amzn.to/3F2hcm7

[richardb15]

suggest you buy/build a dedicated CNCPC that is not a laptop for the bridgeport
good cheap cncpc discussion thread is here.viewtopic.php?t=1914
nice resistive touch screen is here. https://amzn.to/3F2hcm7

Yes I agree the laptop was only a stop-gap to get the machine up and running with minimum outlay. I have a high spec desktop PC here ready to go but no screen at the moment. Just need to wait until June to have the budget to buy one of the Viewsonic ones you linked to then I can make a nice housing/mount for that with keyboard and stuff. The wife blew the May tooling budget on a new Euro toolpost for her lathe so I've got to wait a bit longer.