Build log for my LMS 7550 aka SIEG SC4 lathe

[f3pens]

Hi all.

I had to start a new account as my old one was stuck in a login loop with CNC Zone and IndustryArena. I've been a long time lurker and finally getting around to starting my own build.

I have the Little Machine Shop 7550 which is their tweak on the Seig SC4. It's an average machine that has gone through it's share of breakage and fixes but the time has come for me to get motivated and do some upgrades.

With the long game being a hybrid CNC machine that can still be used as a manual as needed, my first project to tackle is the electronic conversion of the lead screw following the clough42 roadmap.

I purchased his control board setup and ordered up my servo, encoder and a few other bits of hardware.

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Part 1: Planning the layout

The first order of business was to get a good look at the gear train and then determine how extensive the surgery will be to get everything to fit and still be able to close the cover. Here you can see the servo fits nicely under the control panel. If I plan this right, I should be able to get away with just a hole and add a bearing block with an extension to get a pulley into the gear case for the drive servo.

With the servo likely sorted I started to look at how I'd connect up the encoder.

This machine has a belt drive to a shaft that runs inside the headstock where it meshes with the spindle. No clue why it was done this way, but it makes taking a direct read from the spindle a bit troublesome. Without blocking the through hole on the shaft, there is almost no room to mount a pulley directly to the shaft. I considered various ways to adhere a pulley but ultimately figured it was just too much hassle and too little clearance. From there I started looking at the change gears. Luckily there were a pair of 42 tooth gears that are used to setup the threading direction that are a 1:1 ratio with the shaft and these looked like as good of an option as any to tie into. With lots of space available to those gears I got to work in Fusion and put the 3D printer into action.

This is where it stands as of 1/26/23 while I wait for some M5 bolts and set screws to show up. From there I'll get the encoder mounted up and start working on the servo.

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[burs]

Hi all.

I had to start a new account as my old one was stuck in a login loop with CNC Zone and IndustryArena.

Hi, regarding this issue. Could you tell me the old username (here or in a PM if you prefer). I´m sorry that you´ve problems with your login. Problems like this are better reported through our support site. Then you´ll get help soon.
https://www.cnczone.com/index.php?pageid=Site_Support

[ardenum2]

Hi, regarding this issue. Could you tell me the old username (here or in a PM if you prefer). I´m sorry that you´ve problems with your login. Problems like this are better reported through our support site. Then you´ll get help soon.
https://www.cnczone.com/index.php?pageid=Site_Support

I've also had a new issue from a few months back, every time I login 'correctly' it goes to a blank page and stays there. I hit back arrow and then refresh the previous site to complete the login.

[Azalin]

Hi,

Good luck on your build.

I have converted my SIEG C6 few years ago. I'm still using it. From the pictures the SC4 and C6 look very similar. Is the SC4 a newer version of the C6?

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