[MetalZilla]

well done!

[zafarsalam]

Build Thread

Day 4 of our stay in Sadiqabad. Lubricating pumps is installed on the machine. Laid out its pipes and pressure nozzles. Should have been SS tubes instead of Nylon if we were not constrained by time.



Aligned the Y-axis ball screw today. Vertical alignment was out by 0.5 mm and horizontal by 1.4 mm. Fixed them all and in the end we got both the ends aligned within 0.04 mm. Next step would be to fix the ball nut to the end of table.

[zafarsalam]

Build Thread

The next challenge was how to locate the position of ball nut on the table. There were two dowell holes in the nut but those where blind. Mr. Iftikhar had tried to locate them on the table but couldn't do it and he ended up giving us 3 mm loose holes which we were not sure how much misaligned they are.

We first measured the location of mounting threaded and dowell holes on the nut. Reproduced them on another plate with the help of a DRO based mill. Confirmed the dowell holes location on it by placing it on our nut. This plate acted as a template for fixing our ball nut on the table. Moved the table close to the end bearing blocks, put the dowell pins in through the template and tightened the bolts on the nut. Drill 2 more dowell holes through the template and fixed it to the table body. Sounds complicated? Yes it was. And inefficient too. We'll have to fix it later as we'll learn in the posts that follow.



In the mean time oil groves are machined onto the V-shaped ways on bottom of the planer bed. The original groves were almost cleaned up when Mr. Iftikhar overhauled the bed and grinded the v-ways on his planer.



Mr. Nooruddin is still busy with the wiring of motors, switches and other accessories.

[zafarsalam]

Build Thread

8th day of our stay here. We are working 10 to 12 hours a day (week-ends included!). Khalid's team is also helping us out. Motor's wiring is almost getting there. The Z-axis motor drive is 220 V. Mr. Noorudding powered it temporarily from a wall socket and checked it's motion. The other two drives need 400 V. He has to layout some more wires for them.

Mr. Iftikhar had shipped the radial arm end support column from Gujranwala when we were in Karachi. Now I have to locate it. He says that we have to collect it from the Truck stand in the city. He seem to have misplaced the tracking number and receipt from the movers. All he has is their phone number. I contact them and then visit them. I ask them if they received a 10 ft long 500 kg machine column from Gujranwala. One of their employees recalls it and informs us that the customer has already picked it up. We go back to cusomers' premesis and find that it was lying there in their warehouse during all this time. They didn't know what it's for. We shifted it to the machine shop. It is sand blasted and painted with primer.



With all the screws and motors in place, it's time to put the guards on them. I'm not sure what's the effect of pigeon droppings on ball screw lubrication. Don't want to find out either. So better cover them up. Got some made from a local shop in Sadiqabad and a few from the fabrication shop of customer, we start putting them in place over the next few days.

[zafarsalam]

Build Thread

Vertical shaft of the end-support is to be fixed to the end of radial arm. It is an unmachined cast iron surface. We strip out the paint and bolt a flat 30 mm thick plate on it. The bracket will mount on it. After mounting the shaft to it we check it's alignment. It is found 2.3 mm tilted towards the machine at the bottom end. We take off the bracket and and face its mounting surface to take out the tilt and mount it again. Had to do this exercise twice to make it aligned with the machine within 0.1 mm. Alignment in the other direction is done with a tri-square.



We mark roughly on the floor where the base of the end-support should go and then slide the shaft out. It will be installed again when we align the X and Y axes perpendicular to each other and make sure of their alignment by drilling a sqare pattern on a big surface, measuring the diagonals. The radial arm rotation is locked. We now have to figure out how to keep it locked permanently.

[zafarsalam]

Build Thread

Mr. Nooruddin finally gives us the green signal that we can move all the axes with our controller. This is going to be the first test for 5.5 kW motor on Y-axis. We check all the bolts, belts, bearing blocks, lock nuts etc. and give the motor a nudge with controller. IT'S ALIVE!

Need to change the electronic gearing ratio on the drive to get the full speed. Adjusted that and ran it up to the max of 1500 rpm. There is 1:2 reduction with timing pulleys and 10 mm pitch on the ball screw. So it must be giving us 7,500 mm/min of rapids. Checked the torque on the the drive and it showed 35% torque with continuous running and 65% on start and stop. Tweaked the acceleration setting in Mach3 and ended up with a max torque of 50% on the drive. The initial calculations are paying up and behaviour of machine is predictable. So far so good with the bare table which itself is a 5 tons load. X axis motor is running on 10% of it's rated torque. Seems like we selected an extra strong motor for it. We'll check the torque on Z-axis during the drilling process.

With all the axes running we can make them perpendicular to each other. Unlock the radial arm rotation, dial and clamp a tri-square on the table and make other axis perpendicular to it within 0.005 mm in 400 mm length. Lock the radial arm again.

[zafarsalam]

Build Thread

With the X and Y axes aligned with each other we need to lock the radial arm rotation. Can't disable the unlock switch altogether as unlocking is required to move the drill head on radial arm. Just the unlocking of arm rotation is to be disabled. Time to consult the original mechanical and electrical drawings of machine.

The lock happens to be on top of radial column. The locking electrical logic and the mechanism suggests that we need to disable a micro switch on the column. According to company's safety rules we can't climb onto the machine structure or use a step ladder. A scaffolding is assembled around the column, we climb it, trace the wire number of the switch and disable it in the main wiring cabinet. Piece of cake. Took a whole day for this exercise.

[zafarsalam]

Build Thread

It's now time to calibrate the axes and check their repeatability. We have a couple of linear glass scales and a lathe DRO imported from China. These scales would be installed on customer's vertical lathe once we finish the calibration of this machine. X and Y axes steps per mm are calculated from the servo drives encoder count, gearing ratio, timing pulleys' reduction ratio and the ball screw pitch.

Align and install the 2.5 m scale to the Y axis of machine. We get a slight difference in the readings on Mach3 and glass scales. It is because we had miscounted the number of teeth on our timing pulleys. Corrected that and ran the slide at different speeds to check the repeatability. A backlash of 0.3 mm is corrected in Mach and we get a repeatability of 0.05 mm. What a nice feeling to achieve the results after such a hard work.

X axis is calibrated similarly. Got an unusually large backlash of 0.7 mm initially. But soon caught our mistake. We hadn't locked the sliding head against the slide on radial arm. Without locking we got a scewed movement of the head which appeared as exeggerated backlash. The backlash with the locks on was 0.25 mm on X.

Z axis was a bit tricky. We didn't know about the internal gear reduction on the handwheel. What we did was put a 300 mm high block on the bed and touched it's top and then the table with a dial indicator on the quill. Noted the difference on Mach Z-axis DRO. Corrected the steps per mm value in Mach accordingly and we are back in business. Z-axis gave us a backlash of 0.6 mm. This was expected as there was a lot of gearing involved in it's movement.

Limit and home switches are also installed while this exercise is underway. End-support column and the guard cover are in the paint shop. Tomorrow we will check the repeatability on Y-axis under 2.5 tons load. Put the end-support column in place and we are finished. I'll be home well before my daughter's birthday

[zafarsalam]

Build Thread

Finall we reach the day when we have to test out machine with load on it. First we check the diagonal mesurements on the bed with a sqaure drill pattern. Clamp an acrylic sheet on bed and drill 4 holes on a 1000 mm square. Get 2 m Vernier Callipers to measure the diagonals and these are within 0.04 mm of each other. Goal achieved.

Now we shift the loads from the cranes yard to the shop and put them on the machine bed one by one. It's now roughly 2.5 tons loaded onto it. We jog the Y axis again and check the torque on motor drive. It's 60% on start and stop, 40% on continuous run at full rapids. So far so good. Hook up the linear scale again and we spot a trouble. The repeatability is out by a lot and the backlash is changing with each run.

Click here to watch the video for load test on the machine



It's panic time ... Ok, let's be calm. Check the system closely and try to find out the weak points. We check the deflection on bearing blocks. It is slightly increased than before. Tightened the bolts some more and it is back to where it was. But still the problem is there. Now check the ball nut mounting on the table. This is giving us a huge deflection. The ball nut mount contraption which we used earlier is proving to be too flimsy. Tried to tighten the bolts on it and ended up breaking one up in the middle. It is decided to remove the nut locating plate altogether and drill bigger holes for the dowell pins to fix the nut with the table.

A magnetic base drill is arranged. Put on the machine table and work begins on it. We worked from 8 am till 10 pm that day. And by the end of day we had done all the machining to fix the ball nut. We will come again tomorrow morning and install the nut and test the machine once more under load. Lost my camera that day. Rest of the photos were taken by Khalid's camera. I foresee another two to three days work. I wonder if i can make it back before my daughter's birthday.

[zafarsalam]

Build Thread

Next morning we test moving our bed again. First we check the deflection on the ball nut mounting. It's not noticeable on the dial indicator. The deflection on bearing blocks is also less than before. We load the bed again and give it a trial. This time all the things work perfect. It's almost lunch time and we decide to put up the end-support column after lunch and finish it by evening. We'll do the drill test runs the next day.

The end-support column is back from the paint shop after lunch. Two days earlier we had drilled and put in the anchor wedge bolts for it's base plate. It was installed, levelled and then sealed with grout the next day. We can bolt up the end-support to it today. We hoist it up and put it on the bolt holes on the base plate. The mounting holes on both plates are out a little. Move the end support to the horizontal boring mill and slot the holes a little. Put it back on the base plate and it fits perfectly.



Now there's another problem. What will happen when someone presses the switch to move the radial arm up or down. With it securely bolted to the end-support, any up or down movement will stress both the radial arm and the end-support. We need some safety which will prevent the movement of radial arm when the bolts on end-support are tight.

After discussing some options it was decided to put a couple of micro switches on the end of bolts which secure the radial arm against end-support shaft. The switches will cut off the power to the drive motor which moves the arm. The power is restored only when both the switches are free from the bolts. With these switches installed and connected them to the control panel wiring we test their operation. It's a success. We call it a day and plan to do actual drilling the next day.

[zafarsalam]

Build Thread

It is Sunday and we are going to do drill tests today. It is going to be our last day in Sadiqabad (hopefully ). It will be our third Sunday here and Khalid has been with us all those week-ends.

Khalid has modified the post processor for Visual Mill and has put in extra M-codes for locking and unlocking the drill head during each drill cycle. He makes a sample program and we are ready to go. Put a center drill in the drill chuck, center the work piece, adjust height of tool and we press the start button. Works smoothly and finishes the cycle. Now put in a 20mm drill, edit the drill depth and run it again. Within half an hour we are through with the drilling.

The coolant pump is in operation too but the coolant drain system is not finished yet. So we apply a little amount of coolant manually for this operation. Measured the holes, inspected the drilled hole finish, noted down the speeds and feeds. Every thing is perfect.



Click here to watch video of the first run

Last few hours are spent in putting on different indicators on the machine. We leave Sadiaqabad at night and by next morning we are in Karachi. Right on time for my daughter's birthday .



Guards for the Y-axis slide ways and the ball screw are in fabrication shop. I have to go to Sadiqabad again next week to look after the installation of guards and also discuss a few more accessories for this machine. More photos and vids to follow that visit.

[DareBee]

Nicely done.
Upon reading this maybe a few more people will understand why custom machinery costs 100s of thousands.

[Khalid]

Darebee you don't know these guys.. they are Jinns... Just see their website and youtube videos they are really professional designers..

[The Swede]

Well, not only good designers and good on executing. Also VERY good on documenting and presenting the project in this thread. Very nice reading. For a thread as close to 100 out of 100 you can come in my opinion

[Bloy2004]

I would think now it should be called a MILL-drill..
It appears to have great milling capabilities now after the conversion.
..looking forward to a video of the machine during a milling operation.

[zafarsalam]

Thank you guys for the compliments. It was a unique project for me too. This was the first time I had done complete CNC designing. So far we had been doing CNC retrofits on old CNC structures, which already had properly designed machine elements. Designing and then putting all the things together and then seeing them work gives a lot of self satisfaction. I guess we engineers are addicted to it. Can't live without challenges in life.

[zafarsalam]

I would think now it should be called a MILL-drill..
It appears to have great milling capabilities now after the conversion.

It can do very light milling work. First of all there is skew on the drill head without the locks on. The drill head quill is not good for side loads of milling cuts. And the max spindle rpm is too low for a small milling cutter.

[Bloy2004]

The drill head quill is not good for side loads of milling cuts.

Well, you may get another call-back in the future to fit out a new bearing system and speed range for the quill. I'm just thinking of making at least slots along with the holes it will be drilling. But Hey! The drill has now got great easy mobility to get around the work piece for all its piercing.

Will the machine be able to thread the holes it drills if needed?

Heh! I see a future tool changer that the company will want!

[zafarsalam]

Will the machine be able to thread the holes it drills if needed?

Heh! I see a future tool changer that the company will want!

Hard tapping is not possible with this setup. However with a reversing type tapping head they can tap holes. Another customer of mine has done tapping with a floating tap holder with a setup similar to this.

For this machine they are more interested in grooving the holes. For this, they have a grooving tool head. That is very easy to implement in the drill cycle. I bet Khalid must have tried it by now.

The upgrade they are planning at this time is a VFD to adjust the speeds during operation. A tool changer would be a worthy addition too, but a little difficult to implement with Morse 5 taper holder on the quill.

[Khalid]

Zafar, not tried grooving yet. We are waiting for the Guards to be installed. We have complete exchanger drilling ahead. I hope this thread will not ended here.