pm25-mv z axis power feed

For reason beyond my thinking, I mounted the motor to operate a toothed belt to drive the head. I could just as easily mounted it direct. The PM25 head crank is on the left at the top of the column. I fabricated a mount on the bearing retainer there mounted the motor on the back of the mount. I put too toothed pulleys on the other side of the mount, one on the motor one on the crank shaft. The hardest part was making an output shaft from the motor. as it comes it has a stub about 1.4" long, square with a rounded half. Originally a flat piece of steel was pressed on to this stub. Using the mill I carved a hole in the end of a shaft that went threw two bearings with the toothed pulley between them.

I wish I had more RPMs, seems to take forever running the head up and down, between using a drill chuck or a milling cutter. Fifteen seconds per inch for 2 1/2 inches isn't long, but If I had a 4 Inch quill I wouldn't have to do it.
 
T Bredehoft said:
For reason beyond my thinking, I mounted the motor to operate a toothed belt to drive the head. I could just as easily mounted it direct. The PM25 head crank is on the left at the top of the column. I fabricated a mount on the bearing retainer there mounted the motor on the back of the mount. I put too toothed pulleys on the other side of the mount, one on the motor one on the crank shaft. The hardest part was making an output shaft from the motor. as it comes it has a stub about 1.4" long, square with a rounded half. Originally a flat piece of steel was pressed on to this stub. Using the mill I carved a hole in the end of a shaft that went threw two bearings with the toothed pulley between them.

I wish I had more RPMs, seems to take forever running the head up and down, between using a drill chuck or a milling cutter. Fifteen seconds per inch for 2 1/2 inches isn't long, but If I had a 4 Inch quill I wouldn't have to do it.
Click to expand...

They must have changed the design in the column. My crank is on the top right (facing the machine) I didn't buy the bracket that they make for the motor so I will have to fabricate something to work. I hope to be able to piggyback the bracket and motor to the existing crank flange (rectangular) and I have two nylon gears that I will modify on the lathe to fit the two shafts..... and slot the mounting bracket to allow for fine tuning the gear mesh.

I started some drawings last night with my TurboCad. I've got a few other things to do this afternoon, but hopefully I can get started with the fabrication and lathe work this afternoon. I'll be taking pictures of the project and will be able to post the drawings when I get it done.
 
You are correct, I got it wrong, the handle/head drive is on the right facing the machine. I didn't know about a motor mounting bracket. Enjoy the experience of developing a solution.
 
T Bredehoft said:
You are correct, I got it wrong, the handle/head drive is on the right facing the machine. I didn't know about a motor mounting bracket. Enjoy the experience of developing a solution.
Click to expand...

Did you post any pictures of the motor drive ? thanks,
 
alfaspider said:
Did you post any pictures of the motor drive ? thanks,
Click to expand...

Sorry no I haven't yet. All I have right now is the manufacturer's mechanical drawing.

I am really restricted right now by health issues. I haven't been able to get much shop time since I started the project. Hopefully I'll get my meds regulated and things will settle down soon
 
I need to learn how to read the names on the post's !!!! Blame it on my meds!! ;)
 
Well after several weeks of being my own doctor, I finally got medications straightened out and was able to use the machine for the first time today. Now I get to explain to my doctors where I got my medical degree!!

I had a couple of little projects that I wanted to try out with the machine before I actually started fabricating the motor mount for my Z drive. I'm really impressed with how easy the machine is to operate. Since I am new to milling everything has a learning curve so hopefully I can get started with this mod in the next few days.

I have all of the parts that will be needed so it is just a matter of mounting it and adjusting the gear feed. After today's run I will definately want to get the Z drive done sooner than later and the addition of the X drive will not be in the not too distant future! I'm basically a lazy guy and pushing a button to move the table is a lot more enticing than cranking the table back and forth manually!
 
It's been a while since I updated this thread and I am now nearly finished with the mod. To start off the nylon gears that I picked up had to be resized to fit the 3/8" motor shaft and the 5/8" mill crank shaft. Here I have turned an aluminum insert to fit. After knurling and using some handle grip cement the insert was pressed in and bored for the slip fit on the 3/8" motor shaft.

The set screws were taps for 12-32 and set screws installed and the excess was cut off and faced.
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The support frame was cut and machined for a nice square fit. Notice that there is a 1/8" lip on the end pieces to make it easy to align for welding.

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Mock up with the support taped together.

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After welding assembly is started.

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Original crank is removed.

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12 volt power supply is mounted to the wall abd motor assembly is trial fit on the mill.


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I decided on a spring loaded momentary ON-OFF-ON rotary switch and picked up a perfect box from Amazon. I wanted the box to mount at an angle so used a couple of cabinet hinges to mount. Later I locked the hinge in this position and used JB Weld to make it somewhat permanent.
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I've got the project running now and it works flawlessly. I'll get some updated pictures later.

The motor output speed is 100 RPM and with the gears 1:1 movement is a nice steady 4.25 inches per minute lifting, and 5.58 inches per minute lowering. The motor seems to have plenty of extra torque and runs nice and quiet. It's taken me quite a while to finish the project because of health limitations, but well worth the effort.
 
The finished installation:

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Eventually I plan to wire the 110 volt supply for the power supply into the main control box so that I will have the emergency stop feature. I'm trying to figure out how to add a short Mp4 video to show my project in operation.
 
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