Author Topic: Collet Block in Vertical Slide  (Read 1290 times)

Offline Jasonb

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Re: Collet Block in Vertical Slide
« Reply #15 on: October 15, 2025, 06:59:55 AM »
I suppose a spacer below would allow it to rotate and then it would be a lot more useful.

Offline PaulR

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Re: Collet Block in Vertical Slide
« Reply #16 on: October 15, 2025, 07:15:35 AM »
I suppose a spacer below would allow it to rotate and then it would be a lot more useful.
Good idea, I'll have a look when I get time, quite a busy week ahead.

Offline PaulR

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Re: Collet Block in Vertical Slide
« Reply #17 on: October 16, 2025, 06:09:41 PM »
I suppose a spacer below would allow it to rotate and then it would be a lot more useful.
Good idea, I'll have a look when I get time, quite a busy week ahead.
Had a look at the various work-holding options at the show today and decided to go with a vice and a vee-block which cover all the basic orientations, shapes and sizes I need to hold at present. The vee-block was a one off without a clamp in a rummage box, in new condition and a bargain  ;D

On the slide itself, I found that what is effectively a cup washer around the screw within the aperture had been made a little to thick and was protruding above the back face causing work to rock - a quick visit to the lathe solved that and things seem to sit nice and square now (will clock it in the next day or two). A piece of scrap above the vice will protect that machined surface and a parallel behind the vee-block brings it to pretty well centred under the three screws with a suitable piece of packing to protect the work. I'll have a good play with this over the next few days.

Offline PaulR

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Re: Collet Block in Vertical Slide
« Reply #18 on: October 17, 2025, 08:29:07 PM »
Set up a DTI on the bed with plunger on the back of the slide's aperture and wound the cross slide back and forth as far as I could. If flickered within plus or minus 0.0015 - good enough!

@Jason if you're reading this: I had brain fade previously when I said the protrusion at the bottom of the slide would hit the casting... I was looking at the compound casting which obviously has to be removed  :facepalm: It'll take some fiddling around to try to get a 45 degree cut due to the limited travel of the cross slide but it might be possible.

This pic shows a few test cuts in bits of scrap, a ~6mm deep 3mm slot in brass (did a shallower slot in some steel as well), a cut at about 20-30 degrees just to see what it was like and a bit of milling using the side of the endmill. No dramas although my arm was really aching after cutting that slot as I had everything tightened down including the gib strips maybe a bit too much.

I made and hardened a little centre/pointer to go in the chuck. For this slot in brass I tried to align this centre in a hole in the end of the brass but I obviously didn't get it quite right as the cut slot isn't properly centred - probably better to use a finer scribe-like point to align with a scribed line on the end of the rod.



Offline Jasonb

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Re: Collet Block in Vertical Slide
« Reply #19 on: October 17, 2025, 08:45:03 PM »
Have a google for "sticky pin method" to get a fine true running point, this sort of thing, though I use the end of a steel rule rather than my finger on a wobbler but the pin does the same sort of job.

https://youtube.com/shorts/KHxBQNxBMX8?si=aRoOWPIjuK6GAeek

Offline PaulR

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Re: Collet Block in Vertical Slide
« Reply #20 on: October 17, 2025, 08:56:16 PM »
Have a google for "sticky pin method" to get a fine true running point, this sort of thing, though I use the end of a steel rule rather than my finger on a wobbler but the pin does the same sort of job.

https://youtube.com/shorts/KHxBQNxBMX8?si=aRoOWPIjuK6GAeek
Ah yes, I remember seeing that method years ago when I had my last lathe but never tried it. But will it work horizontally... I'll give it a try!

 

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