Advice for DIY Z Axis Power Drive

[sfsteel]

I’m investigating adding a Z axis power drive to my Precision Matthews PM30-MV mill.

I was looking into motors, and had some questions regarding what type of motor to go with.

Based on people that convert to CNC, it looks like I can get away with a motor rated at 900oz per inch or greater. So I was investigating a Nema 32 stepper such as this, or a geared DC motor like this. My working knowledge of these motors is pretty little.

I don’t have any plans to CNC, but are there any advantages to the stepper motor? Any tips from somebody that has been down this road?

I may want to do something similar for the X axis.

Thanks!

 

[TomS]

I’m investigating adding a Z axis power drive to my Precision Matthews PM30-MV mill.

I was looking into motors, and had some questions regarding what type of motor to go with.

Based on people that convert to CNC, it looks like I can get away with a motor rated at 900oz per inch or greater. So I was investigating a Nema 32 stepper such as this, or a geared DC motor like this. My working knowledge of these motors is pretty little.

I don’t have any plans to CNC, but are there any advantages to the stepper motor? Any tips from somebody that has been down this road?

I may want to do something similar for the X axis.

Thanks!

Here's a couple of pictures of my RF-30 Z axis power lift. The motor is a RV slideout motor I had laying around. Way over kill for this application but it's what I had.

While a stepper motor would certainly work to will need a power supply and driver to make it work. Could get a bit pricey compared to a geared head AC or DC motor.

My thinking is 900 oz in is way more than you need. When you did your calculations did you consider the gear ratio between the lift handle and the Z axis lead screw?

Good luck with your project.

 

[sfsteel]

I’m investigating adding a Z axis power drive to my Precision Matthews PM30-MV mill.

I was looking into motors, and had some questions regarding what type of motor to go with.

Based on people that convert to CNC, it looks like I can get away with a motor rated at 900oz per inch or greater. So I was investigating a Nema 32 stepper such as this, or a geared DC motor like this. My working knowledge of these motors is pretty little.

I don’t have any plans to CNC, but are there any advantages to the stepper motor? Any tips from somebody that has been down this road?

I may want to do something similar for the X axis.

Thanks!

Here's a couple of pictures of my RF-30 Z axis power lift. The motor is a RV slideout motor I had laying around. Way over kill for this application but it's what I had.

While a stepper motor would certainly work to will need a power supply and driver to make it work. Could get a bit pricey compared to a geared head AC or DC motor.

My thinking is 900 oz in is way more than you need. When you did your calculations did you consider the gear ratio between the lift handle and the Z axis lead screw?

Good luck with your project.
View attachment 260863

View attachment 260864

TomS, that motor rating was based on putting the motor on top of the column (and leaving the handle in tact). In which case wouldn’t have any geared ratio because it’s directly driving the shaft. I’m not opposed to going your route though.

Do you know the specs of your motor? Do you ever wish u still had the option to hand crank in certain scenarios?

My “calculation” was simply looking at CNC conversions and using those motor specs.


Sent from my iPhone using Tapatalk

 

[TomS]

TomS, that motor rating was based on putting the motor on top of the column (and leaving the handle in tact). In which case wouldn’t have any geared ratio because it’s directly driving the shaft. I’m not opposed to going your route though.

Do you know the specs of your motor? Do you ever wish u still had the option to hand crank in certain scenarios?

My “calculation” was simply looking at CNC conversions and using those motor specs.


Sent from my iPhone using Tapatalk

Now I understand. Unfortunately I don't have any motor specs. I bought it as a spare for a RV I no longer have. It is very high torque because it had to move a slideout that weighed several hundred pounds.

I don't miss using the handle. The motor gear ratio is such that the head moves up and down slowly. I don't use the gear motor for machining operations, just positioning the head vertically.

 

[mrjbinok]

I too am looking into the possibilities of converting my PM25-MV Z Axis. From the web searching I have done in the last week or so one motor/gear spec that seems to stand out is the geared RPM which seems to be anywhere from 50 to 100 RPM's so I have narrowed my search to around 80-85 RPM's. The 24 Volt DC motors seem to have higher torque ratings over the 12 volt versions and I am guessing that at least a 5 Amp rated output, 24 Volt Power Supply would be needed. There seems to be quite a few geared motors in this range that are available.... and IF you're not in a hurry to receive it, there are plenty available from China with free shipping on fleabuy for under $100.

I'm still researching all that I can find on the subject and since I don't have my machine set up yet (due to cardiac issues) pounding the keyboard will at least keep my mind occupied!! Keep us posted on your progress. Jim

 

[TomS]

I did a quick search on eBay for slideout motors. I found that the motor I'm using is an Adacel. Not cheap! About $330. But there are several others for under $100. You might find something that will work for your application.

 

[talvare]

I built a knee drive for my BP mill a few years ago using a small Bodine gearhead motor I bought on e-Bay. I fabricated a mount and machined components for a manual clutch mechanism. The clutch acts as a safety device to adjust torque and allows me to dis-engage the drive so I can still crank the knee by hand. Here's a couple of photos:


..........and yes, I did fabricate and install a chain guard.


Ted

 

[hman]

Another candidate for a Z axis motor is a "big dish" satellite TV positioner motor. If you can find a friendly local satellite TV installer, he may have a couple left over from the good old days, and they might cost you something like $20-30. A typical motor takes 24-36 volts DC. And as an added bonus, the gear box contains settable limit switches, so you won't need to add external ones. See my post #8189 on Page 273 of "POTD":

https://www.hobby-machinist.com/thr...in-your-shop-today.14637/page-273#post-423287

 

[mrjbinok]

I built a knee drive for my BP mill a few years ago using a small Bodine gearhead motor I bought on e-Bay. I fabricated a mount and machined components for a manual clutch mechanism. The clutch acts as a safety device to adjust torque and allows me to dis-engage the drive so I can still crank the knee by hand. Here's a couple of photos:
View attachment 260942View attachment 260943

..........and yes, I did fabricate and install a chain guard.


Ted

Great idea for the coupling/clutch. I'll have to look into similar construction ideas that I could easily adapt.

 

[mrjbinok]

I did a quick search on eBay for slideout motors. I found that the motor I'm using is an Adacel. Not cheap! About $330. But there are several others for under $100. You might find something that will work for your application.

I did the fleabuy search for your slide out motors and came up with plenty to look at.... You're right about about some being high on the pricey range but there are some definite possibilities.

My previous searches have kinda centered on this motor. It has the right RPM range and doesn't seem to require excessive current draw

https://www.ebay.com/itm/24V-Volt-R...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649