A question for turners or machinists

VicS

VicS

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Prompted by Philip Stevens quest for knurled nuts I had a look at the collection of lathe tools i inherited and found that i do in fact have a small two wheel knurling tool (not the clamp or scissor type just the simple one that you push up against the work)

I have no idea about using it though.
What speed to you run the lathe? very slow with the back-gearing in use or faster?
 
Hi Vic, I have the same as you, I have run it at slow speeds and mid speed, I just have a Myford Tri-Lever. Seems to do the job.
 
I always use it at slow speed - say around 50 - 100 rpm, gradually apply the pressure while simultaneously moving the tool with the saddle feed to and fro along the work. A cutting oil helps as well. Check the tool is clean before you start (they can get a bit clogged up if used on soft metals) and don't back the tool off and back in to the work, as the knurling won't line up again - you end up with a sort of 'double knurl' if you see what I mean. It needs quite a bit of feed pressure to achieve a decent looking knurl.
 
Thanks for the advice. I guessed it would be a slow speed.

It a very old prewar small industrial lathe made by Sears Roebuck in the USA, (A clone of an Atlas we believe) bigger though than what most people have in their garages!
 
It's a knack. Practice before putting the work in. You can run as slow as you like until you get confidence. Easy, though, when you've got the knack. If you cut the knurls too deep they are mucky and unpleasant to use.
 
Make sure your tailstock/running centre is well placed and holding.makes a bit of a mess if it aint(if your using it of course)
 
As everyone said run the machine slow around 2 or 300 rpm. If you are only making knurled nuts make sure you only have the minimum amount of material protruding from the spindle for rigidity as the pressures required are quite high. Make sure you set up the knurling tool dead square to the workpiece, lightly touch on the knurling tool until you get a light imprint on the bar over the full wheel width (Re-skim bar before starting process). Bring the tool up to the end of the job about half the width of the wheel. Touch wheel on to job and feed along, at the end of the stroke load a little more and feed back again and so on until required depth is achieved. As also said make sure you use plenty of coolant or cutting oil.
I will warn you there is an art to it and it might take a while to master it. Straight knurling is a lot easier than diamond knurling.
Have fun
Adaero
www.adaero.co.uk
 
Method I use is to turn the job 5 thou bigger than the finished dia, coolant of lightly mark job, Then inspect to see if the marks are even with No double cuts, if there is, turn a couple of thou to remove marks, Do Again,i f ok, continue till satisfied usually get a perfect knurl each time doing it this way. Clean with coolant and brush before handling as knurls produce long sharp swarf.
 
If you can find enough people that want a few go to a machine shop and have them made. The more you order the cheaper they become.
If you are making them out of aluminium get them hard anodised. Most plating shops though will unfortunately have a large minimum order charge of around £50 so they would be better made in 316 stainless. Another point to consider, if you go with aluminium and they are done and undone regularly then you should consider having a stainless steel helicoil fitted as they will wear rapidly.
 
[ QUOTE ]
Most plating shops though will unfortunately have a large minimum order charge of around £50

[/ QUOTE ] It's always worth looking around for someone who will do small jobs.

For anyone on the Solent area there is an anodisers in Seagull Lane, Emsworth who do small jobs. No more info or idea of prices, but somewhere to check if you are in that area and need something anodised.

Frost.co.uk do an anodising kit but at £100 and another £62 for the dye kit if you want it coloured is hardly an economic proposition for a small one off.

Incredibly simple to do though with no special equipment, at least nothing that wasn't to hand in a school science department. I did a couple of bits some years ago, coloured one orange as well with fabric dye but unfortunately I don't now have the instructions.
 
I've not had good results with plating diamond knurls. Have jap blacked instead.
 
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