T slot cutter of woodruff cutter?

[Mark Gould 1Participant @markgould1]

Gents,

I am making a spindle lock for my Emco FB-2 milling machine. I am using Graham Meeks design which is made from a single piece of metal. I am using EN1A.

Grahams design has a long slot which carries the actual locking piece. My question to you is, should I be using a t slot cutter or a woodruff cutter? I am unsure what the difference is between these 2 cutters.

Thanks in advance for any help,

Mark

[Mark Gould 1Participant @markgould1]

[Mark Gould 1Participant @markgould1]

Here is Grahams drawing, I hope he doesn’t mind me posting it here. It clearly shows the 60mm long slot which has to be milled out. 
 

Edited By Mark Gould 1 on 03/03/2020 16:56:00

[EmgeeParticipant @emgee]

Not familiar with the design but normally use a slot drill for slots, some T slot cutters have cutting teeth on all 3 sides of the cutter, a Woodruff cutter only has teeth on the circumference of the cutter.

Now I have seen the drawing I would use a slot drill to remove material to the width and depth of the slot then a Tee slot cutter for the remainder. Using a slot drill lightens the load for the Tee slot cutter.

Emgee

 

Edited By Emgee on 03/03/2020 17:00:13

[Tony Pratt 1Participant @tonypratt1]

As above remove as much material as you can with an endmill/slot drill, I would use a tee slot cutter which has cutting faces on both sides & the circumference if one is available that small?

You may get a far bit of distortion in this part if using cold rolled steel, so rough out all faces first & stress relieving would be good.

Tony

[Neil WyattModerator @neilwyatt]

The main thing is that Woodruffe cutters have thicknesses and diameters to match standard Woodruffe keys.

T-slot cutters have sizes to match standard t-slots.

Neil

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[Anonymous]

As I would expect a careful study of the drawing shows that the central slot is slightly deeper than the slot itself. So cut a slot slightly deeper with an endmill or slotdrill and then use a T-slot cutter. Cutting the central slot slightly deeper stops the T-slot cutter from potentially cutting across the full width on one side.

Andrew

[John ReeseParticipant @johnreese12848]

In that application I think a Woodruff cutter would work quite well. If a T-slot cutter is available in a 6mm width it would also work quite well. The process I am visualizing is this: cut the 20mm slot to 8.5mm depth first, then do the undercuts one at a time using either the woodruff cutter or an appropriate T-slot cutter.

[Mark Gould 1Participant @markgould1]

Thanks all for the advice. I will look at an appropriate woodruff cutter and proceed carefully. My plan is, as you have advised to get everything out of the central slot with an end mill first and then do each “side slot” separately.

@Tony, how should I stress relieve it?

Mark

[Tony Pratt 1Participant @tonypratt1]

The recommended process is to heat up to 600 to 680 deg. C & cool slowly, not so easy in a home environment but I have used a wood burning open fire to good effect, it gets the job done but a fair bit of scale can develop on the metal if left in too long.

Tony

[Clive HartlandParticipant @clivehartland94829]

As stated, Mark is using EN1A, so just do it, no heat treatment needed.

[Mark Gould 1Participant @markgould1]

Ok thanks to you both,

Mark

[Phil H1Participant @philh196021]

Mark,

The snag for me is that I don't quite understand how the part fits the machine but could the whole thing be redesigned. It looks like a very complex part for a very simple function.

Phil H

[Mark Gould 1Participant @markgould1]

Phil,

Here are 2 photos showing the device installed. I think it’s quite an elegant design and although a lot of material needs to be removed, what you are left with is an effective device for solving the annoying problem of not having 3 hands.

Mark

[Mark Gould 1Participant @markgould1]

Again, these are photo’s Graham himself has put up here so I hope he doesn’t mind me re-posting them.

Mark

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