G0678 CNC Conversion Thread

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Dave_C
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

I have a weird combo of shaft sizes...3/8” on the motor and 5/16” on the ballscrew. Only have a hair over 1” OD available before I have clearance issues.
Not a problem, there are sizes smaller than the one I bought and you can order each end piece in the size you need!

Just make sure to pick ends from the same coupler size! 20,30,40 and so on but each end can be a different shaft size.

I think the sizes are the diameter in MM so a size 30 is 30 mm and a size 20 would be 20 mm. I don't have the chart in front of me but I think that is correct.

My 40 size has a 1/2" on the motor end and a 12 mm on the ball screw end. So it is nice to be able to just order the fit you need and not have to do anything to them.

Dave
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
Dave_C
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Progress Report:

Here is a picture of the front Y axis belt/pulley cover. This should keep the shirt tails out of the pulleys! :D

Spindle encoder is on the way as are the pulleys and the belts for the Z axis and the encoder.

Stay tuned, we'll be right back with a rigid tapping video after this commercial break! Yeah, right. There is still lots to do before I make any holes to tap.

Dave C.
Attachments
0213180928.jpg
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
martyscncgarage
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Re: G0678 CNC Conversion Thread

Post by martyscncgarage »

Looking great Dave! Top notch job!
Reminder, for support please follow this post: viewtopic.php?f=20&t=383
We can't "SEE" what you see...
Mesa, AZ
DICKEYBIRD
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Location: Collierville, TN USA

Re: G0678 CNC Conversion Thread

Post by DICKEYBIRD »

martyscncgarage wrote: Tue Feb 13, 2018 12:36 pm Looking great Dave! Top notch job!
+2 on that Marty!

Speaking of looking good Dave, your pictures all have the same "clean look." I realize you do VERY clean work to start but your pics all seem to have a unique look that is very appealing. I'm guessing you don't use a flash and have a bright but "soft" light source or you use a filtered flash unit? High-end camera?? You could tell me but then you'd have to kill me?? C'mon, let's hear all about it! :)
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
Dave_C
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Well to tell the truth I take all those pictures with my cell phone! I don't use a flash because I have Florescent lights in the shop. The dust on the bulbs is my soft filter! That should get a laugh...

My cell phone is an LG-G2 which is 4 years old, I think. ;)

But hey, what ever works,

Dave C.
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
DICKEYBIRD
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Re: G0678 CNC Conversion Thread

Post by DICKEYBIRD »

Dave_C wrote: Tue Feb 13, 2018 8:09 pm Well to tell the truth I take all those pictures with my cell phone! I don't use a flash because I have Florescent lights in the shop. The dust on the bulbs is my soft filter! That should get a laugh...

My cell phone is an LG-G2 which is 4 years old, I think. ;)

But hey, what ever works,

Dave C.
:lol: Shows how much of a photography expert I am! What you're doing looks good to me on my monitor. :)
Milton in Collierville, TN

"Accuracy is the sum total of your compensating mistakes."
Dave_C
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Question:

I received my encoder today from Automation Direct. 2500 PPR and I am looking at the drawing that came with the encoder and also looking at the P10 pin out drawing on the Acorn drawing S14819.DWG.

Everything makes sense except that pin #1 on the P10 is labeled N/C which I take to mean "not connected" instead of "normally closed" as normally closed would not seem to apply here. Is that right so far?

Second question: My encoder has a blue wire labeled as 0V and I am making the assumption that attaches to Pin #2 which is labeled "COM" in the P10 diagram. Is that correct?

The others are simple and that leaves just the shield wire and when I ring it out with the Ohm Meter I get no continuity to the case of the encoder which makes sense as you would want to ground only at the P10 end.

So does the shield wire attach to the case of the DB9 connector? (acorn end)

I'm using a modular connector with insert holes and screws so moving wires is real easy if I need to move anything. (not wired just yet)

Wires are all tinned and ready but I like to ask questions when I come to a task I have never done. [ and this is my first encoder install]

All help is appreciated,

Dave C.
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
Dave_C
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Progress Report:

I have the encoder mount almost complete, I just need to put the slots in for the mounting bolts and the three set screws to allow for alignment of the belt. I'm still waiting on the pulleys and belts for the X axis and the encoder.

The encoder mount uses two 10 mm bearings, a shaft made from W1 drill rod with a 10 mm x.300" step on the bottom end, a 8 mm x .400" step on the top and then a 10 mm step below that for the upper bearing. That leaves 1.440" in the middle to mount my 2.670" timing pulley of which there will be an exact match mounted below the 5" spindle pulley.
0218181223.jpg
I also finished the tool change idea that lets me raise and lower the knee as needed to compensate for longer or shorter tools. The way this works is I set my part Z zero with my first tool. After I use that tool and I'm ready for a tool change I make a G28 call and move to my tool change position away from the part. With this .250" dial indicator and the mount I made from scrap, I can establish the height of the tool I set my Z, make a tool change and then just raise or lower the knee till the needle is at zero and I'm back to the same cutting height as I was before but with a different tool length.
0218181223a.jpg
So no tool lengths to set in my tool tables, just the tool diameters! I won't have to worry about getting tools back in the spindle at an exact height because I will make a quick measurement on every tool change. It is not as fast as having it all in the tool table but with a little less than 4" of Z travel I needed to come up with a way to compensate for a drill chuck, reamer and other tools that would exceed the 4" travel available.

We'll see how well it works once I get this all done.

Dave C.
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
Dave_C
Posts: 669
Joined: Wed Nov 15, 2017 8:25 pm
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Progress Report:

I had an issue with the HLFB (High level Feed Back) outputs on my Clearpath servos when I tried to series them in a loop for "drive Fault".

Any of the motors wired to the Drive Fault input would work but when I put them in series I kept getting false alarms. The answer was provided by Gary and he included a video on how these relays can be installed.

So $10.00 later and the problem is solved. This simple relay turns 4 inputs into one or in my case I just used 3 of the relays with the NO contacts wired in series so if any of the servos fault I will get an open line and that will trip the drive fault input on Acorn.

I got it off of Amazon!

Dave C.
0227181904.jpg
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
Dave_C
Posts: 669
Joined: Wed Nov 15, 2017 8:25 pm
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Location: Springfield, MO. USA
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Re: G0678 CNC Conversion Thread

Post by Dave_C »

Progress Report:

I've been off the forum for a bit but I have been busy!

I got the timing pulleys installed on the Z axis but now my belt is too short. Somebody changed the pulley center from 4.5 to 4.0 and forgot that he had already ordered the belt. (the new one is one the way)

I also got the encoder pulley installed on the spindle shaft. I had to make a fixture to hold the pulley so I could take a 2.667" pulley and bore out the center to 2.126" (54 mm) and it went on with a nice firm interference fit. I can't pull it off by hand so maybe it will stay put without any locktite.

I also got the belt cover made for the Z axis, checked the rotation of my encoder and now I'm ready to attached the encoder to the machine after I fit the matching timing pulley to the assembly.
Fixture Plate for Pulley
Fixture Plate for Pulley
Z Axis pulleys
Z Axis pulleys
Z Axis Belt Cover
Z Axis Belt Cover
I'll make another post to show the timing pulley on the spindle!

Dave C.
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
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