CNC Milling Machine

@m3ch not going to lie, I chucked pretty hard at your fork in the road picture.

Regarding your question, the DYN4 Servo drive is a little weird when it comes to the wiring. The alarm on the servo is connected to COM pin 5 through a phototransistor. When the drive enters an alarm state, pin 5 goes from high to low. So really Pin 5 is what LinuxCNC is looking at to see if there is an alarm. Does that make sense?

Check out this wiring schematic I received from DMM:

Ahhh I see, that is similar to my servos drives wiring scheme. Thanks for that, that diagram is quite useful as a cross reference. Cheers David,much appreciated.

Don’t leave us hanging! You will need to post your conversion!

2 posts were split to a new topic: Hare and Forbes 46B (Rong Fu clone)

@TCandee SLS 3D Printed GT2 Pulley that fits over a 28mm spline shaft :sweat_smile:

Its actually working great! Thanks for that idea.

Sweet. Looks good. Can’t wait to see the whole thing put together.

3 posts were split to a new topic: Converting a PM-728VT or PM-833TV - Questions and Discussion

I dropped off for a little while but getting back in the shop. Gotta love the military. Pretty much picking up where I left off. Im now just waiting on the nuc5 to come in and get back to the software side…

Hello Dr.D-Flo,
I am attempting to control the PM-833VT VFD with the 7i76e, are there any references as convenient as your other wiring guides that you know of?

Would you mind sharing your spindle timing belt pulley CAD file? I am going to have to reconfigure my encoder for the new drawbar and this may save me some time and headache.

Here is the fusion 360 link:

I have an extra printed one if you want me to ship it to you. You were incredibly helpful in making that video, and it would be awesome to pay it forward.

Thanks. I appreciate that but I can print it here. Just now getting my ultimaker up and running. It looked like you had the dimensions of the spline real close.

Todd Candee

Yes that is because I printed it with SLS. Much better tolerances.

I’m actually printing nylon at very close tolerances now. Took some testing to get the shrinkage right but I printed the entire encoder mount including the timing belt pulleys within .05mm. scaled the parts to 1.01 to account for shrinkage. Bearings mount perfectly and timing belts fit nice. hoping to continue with this accuracy.

In my PDB conversion from TTS to R8 I decided to address my encoder mounting issues since I am going to have to move it. I wanted to address the “round belt” issue that I received criticism for but never had a problem with and the axial strain that the belt was putting on the encoder bearings.

I did my lathe first just because I was waiting for some parts for the mill.

The mill encoder mount is printing now.

Thanks David for the pulley file but I didn’t end up using it. I decided to mount mine a different way that would utilize some existing parts.

Attached are som pictures of the lathe encoder mount.

Looking at converting my PM833T mill to CNC and like the overall approach that you have taken. I’m interested in using servo drives and motors. I was taking a look at your Servo Drives diagram on your Manual to CNC Mill Conversion page Manual Benchtop Mill to CNC Conversion
I noticed that the mains power wiring for the control logic input power is shown incorrectly. Your diagram shows mains power going to the T3 terminal block which is for the regen resistor connections. According to the DYN4 Instruction Manual mains power goes to L1 and L2 on the T4 terminal block.
I’m guessing most would double check (and they’d be wise to) manufacturer data before making any connections. But, just in case.

I am almost complete with my R8 PDB conversion from TTS on my Pm-833MV. I ran the first part with the R8 ER20 holders I purchased and was able to run a 3/8 carbide flat endmill at .112" stepover and .505" depth in 6061 aluminum at 65 IPS in a Volumill pattern. This was not possible above 30 IPS with the TTS system. Very nice to chew through aluminum finally. Still have some kinks to work out on the PDB but it functions pretty well. The encoder mount is working well too. I am having to reprint it however due to an error in measurements. Still worked but the belt was out of alignment. I have the parts an tools on the way for a manual spindle lock. I will have to engage and disengage it at every tool change and there will be a saftey lockout while it is engaged. Still working out the code to make this happen.

To be honest I don’t think it needs the lock. seems to work just fine without it.

Dr Dflo,

Wanting to see if you withhold be interested in configuring a nuc for the original setup in the walkthrough? Minus the probe and tool setter.

Hey sorry for the late reply! This has been a super busy season for me with an upcoming wedding and finishing up my PhD. Did you get your software sorted out?

No worries! Appreciate you getting back with me. No I have not I need to get back on it. I got wrapped up with some military stuff and then when I got back from that. Ended up buying an airplane and then fixing that so it’s been busy here as well! my machine is complete it’s just the software side of the house . I’m gonna have to start fresh because I ended up buying the same exact nuc that you had listed in your walk-through.