Sieg C6 lathe - electronic leadscrew

**snowyskiesau** · 15th May 2015, 12:52 PM

I mention in another thread (https://www.woodworkforums.com/showth...76#post1864976) that I was planning an electronic leadscrew modification to my C6 lathe so thought I'd should start a new thread.
It's likely to be a long term project as winter is nearly here ant that will restrict my shed time. I'll cover both the lathe modifications and building/testing the electronics.

A few photos to get started.

with_pulleys.jpg
The drive belts. Fixed toothed belt between motor and idler.
Threading gears have already been removed.

without_pulleys.jpg
Pulley removed from the spindle.
spindle_gears.jpg
Spindle showing gears that engage the threading gears.
spindle_nogears.jpg
Gear on spindle is keyed and slides off. Other gear is bolted to casting
lead_screw_end.jpg
End of the lead screw
stepper_mount.jpg
This hole is (I think) to allow access to the bolt that fixes the lathe to the bench. It just happens to be 60mm wide and 75 mm deep so a NEMA 24 stepper motor will fit in there nicely. I can access the bolt from the other side.

There will be a 40 tooth timing belt pulley bored out to fit on the spindle in place of the gear shown. The encoder will be mounted to another 40 tooth pulley located about 90mm below the spindle.
The stepper will have a 20 tooth pulley and the leadscrew will have a 40 tooth pulley giving a 2:1 reduction. The motor I've ordered is a NEMA24 387 oz/in from Ch4is (who's also providing the pulleys/belts.).

The PCB's for the controller are being made somewhere in China and I should have them is about 2 weeks. All other electronic components have been ordered, mostly on eBay, some I already have.

EDIT: 40t pulleys are not available so using 30t instead. As long as the diameter is sufficient to allow one to be bored out to 30mm, all is well. May have to adjust belt length.
Still trying to find a suitable/affordable encoder.

How can I get images to span across the page rather than one after the other?

**snowyskiesau** · 21st May 2015, 04:07 PM

Parts for the conversion are slowly trickling in.
Bulk of those shown are from AusCNC. The remaining parts are from eBay with free shipping so it will be a few weeks before I have them.
No word on the PCB manufacture status other than 'Processing'

Spent a bit of time yesterday cleaning up the lathe. It's been a while since I used it and the coating of Lanotec I applied had gone hard.
Even after a clean, it's not as shiny as it once was

(
This got me thinking about cleaning my mill, a Sieg X2 but I got sidetracked thinking about what's involved to CNC it...

Slow down Geoff! One project at a time.

**KBs PensNmore** · 21st May 2015, 05:00 PM

Snowy, could you please explain, as to the purpose of making your lathe electronic lead screw?. If you wanted to cut a thread with it, how would it work?
Regards
Kryn

**snowyskiesau** · 21st May 2015, 05:15 PM

You have an encoder fitted to the spindle so the controller can keep track of postition and speed of the spindle.
The software in the controller then works out how fast to run the leadscrew for the required thread pitch and when the start/stop carriage movement .
At this stage, the cross slide is still manual i.e you need to move the tool in/out as required.
I could/might fit a stepper to the cross slide to fully CNC the lathe.

**KBs PensNmore** · 21st May 2015, 05:43 PM

Sounds way to testicle for me. Enjoy doing it.
Kryn

**snowyskiesau** · 30th May 2015, 03:34 PM

While getting most of the electronic components I need for this from eBay is not a problem, the time take for free shipping is annoying - not enough to actually want to pay for shipping but still it slows things down.

PCB's are on their way, should be here this week. I still need to order the encoder,

At least there has been some progress on the mechanical side. Thanks to PDW, the pulleys have been bored and fit like a treat.
The last image shows the pulleys fitted and the stepper motor where I hope it will be. As the stepper is a close fit where it's shown, there's no room for adjustment so I hope I can get a belt with the required number of teeth. I've ordered a NEMA 23 motor as a replacement which is 3mm smaller than the NEMA 24 shown so it might be adjustable enough.

I've found that the shaft where the larger pulley is attached is not actually the lead-screw shaft. There's a 1:1 gear drive from this shaft to the lead-screw, presumably to provide an offset so the gear will fit into the side housing. The gears involved are not tight and have a large amount of backlash. Hopefully the software can compensate for this

I've also been looking at this Myford project as a model for my cross slide modification.

**snowyskiesau** · 29th July 2015, 12:38 AM

A bit of a delay on this project. I finished cleaning up the lathe but now the motor won't start!
No sparks or burning smell so I'm hoping the problem is with wiring I may have disturbed during the re-assembly/cleaning.

I sould go ahead and make the few bits I need to make on the mill but I need to fix the DRO before I do that.

Add to that, the fact that I got sidetracked putting a new blade in the second hand table saw I bought earlier in the year which showed I need to adjust the trunnions which meant I need to take the table saw apart - again.
There's always something that gets in the way...

**wheelinround** · 29th July 2015, 11:05 AM

Geoff time you installed a wee stove in that shed (wish I could do same). I missed this until the latest update looks interesting and well on its way. There is always something to slow us down.

**PDW** · 29th July 2015, 11:47 AM

Originally Posted by snowyskiesau

A bit of a delay on this project. I finished cleaning up the lathe but now the motor won't start!
No sparks or burning smell so I'm hoping the problem is with wiring I may have disturbed during the re-assembly/cleaning.

I sould go ahead and make the few bits I need to make on the mill but I need to fix the DRO before I do that.

Add to that, the fact that I got sidetracked putting a new blade in the second hand table saw I bought earlier in the year which showed I need to adjust the trunnions which meant I need to take the table saw apart - again.
There's always something that gets in the way...

Has it stopped snowing yet? I'm trying to decide when to return home and get back to work...

Lovely warm & sunny day here in Sydney, think I'll go and sit in the sun, have a coffee, take it easy.

PDW

**snowyskiesau** · 29th July 2015, 12:02 PM

It's a balmy 10° here in the ~~sunny~~ Huon Valley.

Just as well I have lots of indoor projects.
How did you handle the recent Sydney cold snap or didn't you notice it?

**PDW** · 29th July 2015, 01:01 PM

Originally Posted by snowyskiesau

It's a balmy 10° here in the ~~sunny~~ Huon Valley.

Just as well I have lots of indoor projects.
How did you handle the recent Sydney cold snap or didn't you notice it?

There was a cold snap? I've been going about the place wearing a T shirt. Bit of sailing, far too much work indoors though.

I've bought another B/port J head to fit to one of my machines as an auxiliary vertical head. Fitting it up will be a good project in my spare time.

Get on with the conversion - I want to see it work. Could be interesting as a retrofit to my HBM.

PDW

**snowyskiesau** · 29th July 2015, 02:31 PM

At least I have all of the components for the electronics side. I hope to do a bit of work on it tonight at my weekly Hackerspace visit.

**wheelinround** · 29th July 2015, 03:08 PM

Originally Posted by snowyskiesau

It's a balmy 10° here in the ~~sunny~~ Huon Valley.

Just as well I have lots of indoor projects.
How did you handle the recent Sydney cold snap or didn't you notice it?

Geoff it was/is cold am and pm unless the winds come up, they did last week and yes we shivered but slowly as the day warmed I got some shed time. I seem to be handling it better than years ago thanks.

**snowyskiesau** · 10th August 2015, 10:49 PM

Good news is the motor in the lathe is not dead. Turned out to be a broken fuse holder.
Being Tasmania, there's only one place I can get a panel mount fuse holder (Jaycar) and that's 670kms away. I'll pick one up on my weekly pilgrimage to Hobart this Wednesday.

**KBs PensNmore** · 10th August 2015, 11:52 PM

Originally Posted by snowyskiesau

Good news is the motor in the lathe is not dead. Turned out to be a broken fuse holder.
Being Tasmania, there's only one place I can get a panel mount fuse holder (Jaycar) and that's 670kms away. I'll pick one up on my weekly pilgrimage to Hobart this Wednesday.

While you're there why not ask for a catalogue, so that you can look up what you need, order it and get it posted out, keeping Australia Post employees in a job to boot.

Sorry that's right, it's all on line now

Kryn

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