Thread: Bringing an old Robot back to life - Surface Grinder.

Well I waited 4 hours and still nothing.

Do I need to be geologically patient?

Simon

Maybe you dont have an MP4 player?

Try the direct link... worked for me.

http://vid38.photobucket.com/albums/...ps240e0f38.mp4

Ray

PS.. I like the internal 2 start acme thread.... very slick.

Simon, I like to actually measure tapers, internal or external, rather than trail fitting using bearing blue or other mediums where you never really know where you are. The tolerance on machine tool tapers applies in one direction only, where the rate of taper on external tapers should only increase above nominal and decrease on internal tapers and is generally around .0001"/in.
I have ground a lot of morse and other tapers using a sine bar to check external and the ball method to check internal. Sorry I can't offer any advice on how to view the video, I am not a computer person.

Stuart, the internal grinding wheel is just a standard 60g Aluminium Oxide which is a bit dirty and glazed after grinding a fair bit of material from the bore.


Lex.

Originally Posted by Techo1

Simon, I like to actually measure tapers, internal or external, rather than trail fitting using bearing blue or other mediums where you never really know where you are. The tolerance on machine tool tapers applies in one direction only, where the rate of taper on external tapers should only increase above nominal and decrease on internal tapers and is generally around .0001"/in.
Lex.

Hi Lex, never ground any tapers and only ever made one taper which was to modify a flywheel which had an incorrect taper for my application. Making tapers etc to a known standard is always going to be better than merely trying to copy an existing taper. That's what standard are for. Desperately trying to work out the taper on the spindle of my sg. Measured it a few times with a vernier and bore gauge and consistently get 2.05" per foot. Can't be right though, what so of standard is that!?

Cheers & thanks for sharing. BTW, I did end up watching the video!

Simon

[QUOTE=simonl;1840415 Desperately trying to work out the taper on the spindle of my sg. Measured it a few times with a vernier and bore gauge and consistently get 2.05" per foot. Can't be right though, what so of standard is that!

Simon[/QUOTE]

How exactly are you meausing the taper with rollers and trig ?

Originally Posted by simonl

Desperately trying to work out the taper on the spindle of my sg. Measured it a few times with a vernier and bore gauge and consistently get 2.05" per foot. Can't be right though, what so of standard is that!?

Why not? 2" per foot is not a terrible number. For a grinder spindle there is not an over-arching standard (MT or JT), so it could be.

While I'd prefer to be in a position to measure tapers there are times when fitting one taper up to another is a reasonable way to to do things - the grinder hubs I made are unlikely to even be used on another machine, so provided the taper matches the spindle it should all be good.

Michael

Originally Posted by welder

How exactly are you meausing the taper with rollers and trig ?

Well, no and may be half my problem! The large end of the taper is so close to 1.000" that I'm calling it 1.000". I measured that with a vernier. It's not the most appropriate method but I have measured it about a dozen times and I keep getting the same figure.

The small end of the taper I am measuring by carefully dragging a telescopic bore gauge through and then measuring on a vernier. That's probably an OK method to use. I'm also getting consistent results with that too.

To measure the length of the taper I'm simply placing the arbor on a flat and using the depth rod on the end of the vernier to measure. All measurements are made with the arbor because I find it easier to get measurements from.

Consistently getting 2.05" per foot taper. If it was maybe 2.01" or 2.02" then I'd be happy to call it a standard 2" per foot taper. Over the close to an inch that I'm measuring the taper, the 0.05" discrepency relates to about 4 thou difference. That's still 0.1mm which I'm sure I'm not that far out.

What a stupid taper. The rest of the imperial world was using 3" per taper at the time. What was wrong with sticking with that!?

Anyway, that's enough about that. This ain't about a Billy Elliot, it's about a Robot!


Simon