Grinding top rake on form tools

[Lawrie Alush-JaggsParticipant @lawriealush-jaggs50843]

Hulo Evrybardy (Hello Dr. Nick)

 

I’m hoping that someone can help me with how to grind a top rake on a form tool I have made.

The tool works well and creates the profile I am after but the chatter is just too much.

All of the other angles are fine, the tool cuts very well but it does require a rake or a hoe and I am not sure about how to proceed.

I though that using a Dremelesque tool with a pencil wheel might do the trick.

 

Thanks, Lawrie

[Lawrie Alush-JaggsParticipant @lawriealush-jaggs50843]

[Ramon WilsonParticipant @ramonwilson3]

Hi Laurie, first question is how important is the exact form.

 

If its not too important you could clamp the tool blank to a small piece of square stock and use this as a ‘visual’ guide to get the back rake angle and keep the blank vertical as the rake is formed on the side of the grinding wheel across the whole form. I use this method to taper the ends of bandsaw material for soldering and it gives good results.

 

However it will in this case change the shape of your form very (very) slightly and that may not be acceptable.

 

You could also make a small piece of tapered packing that will give a degree (modicum) of top rake, slow the speed right down on the last couple of thou too – that’s a long cutting edge you have there – what’s the material you are cutting ?

 

Hope this helps some

 

Regards – Ramon

 

PS Setting it very slightly below centre height may also improve the tendency to chatter

Edited By Ramon Wilson on 27/06/2011 11:43:09

[Lawrie Alush-JaggsParticipant @lawriealush-jaggs50843]

Hi Ramon

 

Thanks for your reply.

The form does not have to be exact, it is to cut a button for a punch and has been designed with aesthetics in mind more than anything else. The tool is ground from a peice of 3/8th x 2″ HSS and is sitting in a tool holder.

I will give your suggestion a try. The material is 1214 or EN1A in English money.

 

Lawrie

 

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