Micro Kinetics / Sherline Benchtop Lathe

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wilson82
Posts: 4
Joined: Wed Aug 10, 2022 6:27 pm

Micro Kinetics / Sherline Benchtop Lathe

Post by wilson82 » Mon Aug 29, 2022 4:48 pm

Hey All,

I am retrofitting an older Micro Kinetics / Sherline lathe with the controller and so far I have been successful on getting the machine ready to test some turning code. I have an existing part all modeled up in Fusion 360 and just attempted to post it. I filtered the post library for turning and the buildbotics post does not show up. I unselected the turning filter, picked the listed buildbotics post and attempted to post it anyway but got an error stating the post doesn't support turning toolpaths(see below for full error). Before I proceed any further has anyone on here retrofitted a lathe yet and produced code out of Fusion360? If so what post worked for you?

Information: Configuration: Buildbotics 4-Axis CNC Controller
Information: Vendor: Buildbotics LLC
Information: Posting intermediate data to 'C:\Users\1982s\Desktop\1.nc'
Error: Failed to post process. See below for details.
...
Code page changed to '1252 (ANSI - Latin I)'
Start time: Monday, August 29, 2022 11:10:12 PM
Code page changed to '20127 (US-ASCII)'
Post processor engine: 4.5874.5
Configuration path: C:/Users/1982s/AppData/Local/Autodesk/Autodesk Fusion 360/CAM/cache/posts/buildbotics.cps
Include paths: C:/Users/1982s/AppData/Local/Autodesk/Autodesk Fusion 360/CAM/cache/posts
Configuration modification date: Thursday, July 14, 2022 8:02:35 PM
Output path: C:\Users\1982s\Desktop\1.nc
Checksum of intermediate NC data: 55af4c05f0b66d3d03a08b97443f3b37
Checksum of configuration: 560330e86ebe6ef93233e9440a17c454
Vendor url: http://www.buildbotics.com
Legal: Copyright (C) 2012-2022 by Autodesk, Inc.
Generated by: Fusion 360 CAM 2.0.13881
...

###############################################################################
Error: Turning toolpath is not supported by the post configuration.
Failed while processing onOpen().
###############################################################################

Error:
Error: Failed to invoke 'onOpen' in the post configuration.
Error: Failed to execute configuration.
Stop time: Monday, August 29, 2022 11:10:13 PM
Post processing failed.

wilson82
Posts: 4
Joined: Wed Aug 10, 2022 6:27 pm

Re: Micro Kinetics / Sherline Benchtop Lathe

Post by wilson82 » Thu Sep 08, 2022 5:31 am

So I tried the Linux CNC lathe post in Fusion 360 and it is now moving but does not think it’s a lathe. The post is picking a G7 code which would be lathe diameter code in Linux cnc but is moving to the true number and not 1/2 the distance from the centerline as it should. So I then tried G8 which would be radial lathe figuring it would try to double the size but it to went the true distance in the program. It’s not picking up either GCode so in my eyes it doesn’t know that it’s a lathe or this post will just never work. I posted it with Tormach post which is another Linux based controller and got basically the same code calling out a G7. Any suggestions out there?

wilson82
Posts: 4
Joined: Wed Aug 10, 2022 6:27 pm

Re: Micro Kinetics / Sherline Benchtop Lathe

Post by wilson82 » Sat Sep 10, 2022 3:30 pm

I have to give a big thanks to Doug for calling me today and we sorted this thing out pretty quickly over facetime. Thankfully there was no need to mess with the firmware to get this thing to act like a lathe. The Buildbotics controller is not designed to take the G7 (diameter turning in linux) or G8 (radial turning in linux) commands so for those who attempt this again in the future just know that that is the case if you use a generic linux lathe post. To sum it up you have two options. Option 1 is to go into the motor settings and double the travel per rev setting in order to make the motor only move half the distance. In my case its a 20 pitch lead screw and mine was set to .0498 in. so we doubled it and made it .0996 and tested that and it most definitely worked but remember if you double that number than you need to double the numbers you are using for your soft limits. The 2nd option is to modify the post processor to generate all of the x dimensions in their radial number instead of diameter while leaving option 1 at its correct setting. Either option will work just fine and is obviously a personal preference. I chose option 2 for the time being and made changes to the LinuxCNC post in Fusion 360. If you need the post for your lathe just send me a message on here and i will gladly send it to you. I will be changing more things in it as I progress with the machine so I don't want to post it and you end up with one that has bugs in it that I haven't sorted out yet.

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Doug
Posts: 315
Joined: Fri Feb 02, 2018 4:56 pm

Re: Micro Kinetics / Sherline Benchtop Lathe

Post by Doug » Mon Sep 19, 2022 3:31 pm

Thanks for your work on this.

wilson82
Posts: 4
Joined: Wed Aug 10, 2022 6:27 pm

Re: Micro Kinetics / Sherline Benchtop Lathe

Post by wilson82 » Thu Sep 29, 2022 5:58 pm

Finally back on testing the lathe and ran into a small problem. I have ran the program several times so far just cutting air over the last week and have had no problems. I put a piece of aluminum in and run the same program with no changes and about half way through the machine goes into Estop and has the message “machine alarmed- command not processed”. I again ran it just cutting air and again ran with no problems. So I set the part back up and tried again to only get the same error. Any reason anyone can think of why this is happening?

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