Hi All,
Plunged into new adventure for fabrication of CNC Portable Milling/Boring machine from readily available material. I am working in a reputable petrochemical industry. Presently, we have to make a 150 x 80x 90mm deep tappered slots (15 degree draft angle) for repair of a crack. The existing portable machine did good job on a mockup but due to increase in depth and lot of vibration issues the mock-up job completed in 90Hrs. Thats a big downtime for a plant.
This is the time to make a more rigid and efficient CNC machine that may be portable and mounted on a circular shell at any orientation .. The CNC will be added benefit.
Here are some pictures of the build. The Cross slides working area is 200mm and the Z-axes can travel 100mm. I used salvaged Linear rails and ball screws for this. The machine base is not casted but we have used 30mm Carbon Steel plate
We hope that by implementation of this machine we will drastically reduce the time from 90Hrs to 12Hrs or less.

The target completion date was 15days from scratch which we have achieved timely. Zafar Salam installed CNC control system. He will describe further in this thread.

Some progress on Controller box and 400watt servo system by KaraCNC from Mr.Zafar Salam.

some more progress...

Machine completed and video of first test run.Here are few picture of 2" x 2" x 20mm deep slot we did with this machine. We have mounted hydraulic spindle maximum 300RPM used 4 flute 19mm end mill. Machining Job took 35Minutes and it was drastically reduced compared to manual machining...
With the passage of time ,The spindle had developed clearances and play in the bearing housing (its an old spindle) which caused some marks on the work piece walls but those are acceptable ...However we are satisfied with the results.. Ahead we are aiming to more rigorous testing on this machine.
https://www.youtube.com/watch?v=RHkk9ji5Tuw&feature=youtu.be

Here in the picture the 65mm deep slot took 6Hrs of time. Previously manual machining with big steps at 30mm took almost 30Hrs of time and the finish was too much pathetic.. The machine was stopped to lengthen the tool with new tool adapter. As it has rough machining with endmill at 1.5mm stepover so we fine not that good finish at the walls but its okay.. We can run another finish machining using ballnose but we no need to....
The cavity walls are at 15degree upto 70mm depth and the remaining 20mm depth is at 37.5degree.Job in progress.

Thank you Khalid for giving me the job of story telling . OK, here it goes ...

One fine evening earlier this month I received a call from Khalid for converting a machine to CNC. They had a couple of portable milling machines at their machine shop and they wanted me to install CNC on one of them. I agreed to it without any hesitation as all his ideas have always been very unique and challenging (I love both these aspects). There was one hitch though. They wanted all that done in 15 days. The deal was that they will do all the mechanical modifications themselves and I will do the CNC stuff. I started work on the electrical panel box (there's a photo of it in Khalid's post) in Karachi while Khalid started his job in Sadiqabad. What I didn't know was that there's going to be a change of plan midway through which is going to make it more difficult (read more interesting) .

We are well into the first week of this project and the controller electric cabinet is almost complete. I send it to the paint shop after doing all the cutting and fitting. Then another phone call from Khalid. And guess what, the plan has changed. They have scratched the idea of installing CNC on an old mill. Instead they are going to build another mill with fabricated structure, linear slides and ball screws. Khalid says that they'll do it within a week and I can go and visit them next week. My first reaction was, they will never be able to do it in the time they have allotted for it. I can stay home for some more time. The 10 hours ride to Sadiqabad is never a pleasant one with the condition of roads we have. And the summer heat of 40+ degrees was too much a deterrent. I was hopeful that monsoon rains will ease up the heat when they finish the machine in a month. But, no. They won't let up. I got the call right on time and it was 46 degrees when I reached Sadiqabad the next week.

The machine was getting reassembled after paint job when I got there. Looked very unstable at first sight. My first thought was, it's going to spit all the bolts out when they put a 3/4" endmill to the job on this one. I could lift the whole thing with my bare hands and I am not a strong person at all. Hydraulic spindle and home switches were yet to be installed. We planned to install the CNC components on it the next day when the mechanical setup would be over. Everything seems OK till now (except for the flimsiness of the machine). We are right on schedule. Three days to go for the 15 days deadline. I am seriously waiting to see the response of machine with a big tool on.

An excellent project guys, thank you for sharing the information and posting all the pictures.

Tweakie.

Machine is transferred to the CNC fitting room from the machine shop. 400 W AC servo motors from Delta are installed on all the three axes. L pitch timing belts and pulleys with 1:3 ratio. With 3000 max rpm of motors and 5 mm pitch on ball screws, we are going to get rapids of 5000 mm/min. Motor power and reduction ratio is selected from experience. We will check the actual load on drives during test runs. Two of the motors were actually dismantled from another CNC machine which we did there 3 years ago. The third motor was taken from Khalid's personal collection. This was all done to meet the deadline. Oh, and the ball screws and linear slides were also from Khalid's personal collection (he was planning to build a 3D printer with them). Any ways, we got all that assembled in the machine shop. Now it's time to do the wiring for motor power, encoders, spindle relay, home switches and emergency stops. After that motors calibration would be done. We are planning to do all that today and perform the test run the next day.