Help Parting On A Curve

[umahunter]

Thanks for all the tips guys one last question I've read conflicting reports on the net when using this t style blade from shars should I grind the top of the blade flat or leave there lil dip ?? As shown in the pic

 

[darkzero]

Leave the dip. It helps fold the chips so they don't get stuck in the groove. If you still have trouble with chips loading in the groove, feed as far as you can, then move the carriage over a bit (to create a wider groove) & continue parting.

 

[Tozguy]

As above post says, I would only grind the end to get the proper relief and to keep the edge sharp. Leave the lip.
The cutting edge must always be the widest part of the tool.

 

[kwoodhands]

I'm parting 2 inch solid aluminum with a 3/32 t style hss blade and as you can see I'm curving I have a filling I may be going to fast but thought I would see if I'm missing anything else as you can see I've got quit the curve View attachment 105681View attachment 105682View attachment 105682View attachment 105681 View attachment 105681

First thing,parting off a 2" round perfectly flat requires sharp cutters,beefy lathe and you will need to widen the cut as you go.Why don't you saw the round a bit over size then face it to dimension.I would think this may be the practical way to go.

mike

 

[Wreck™Wreck]

First thing,parting off a 2" round perfectly flat requires sharp cutters,beefy lathe and you will need to widen the cut as you go.Why don't you saw the round a bit over size then face it to dimension.I would think this may be the practical way to go.

mike

If the part is fully machined on the OD cutting the blanks slightly long leaves no material to hold, if you have to do back work just rough part it as the back will be a second operation anyway.

On large parts that can not be easily parted I use a long piece of stock and turn a part on each end then saw them off and do the back work afterwards.

Parting to center is often a troublesome operation in some materials regardless of machine or tools employed and rarely leaves a nice finish. If you are a hobbyist with plenty of time just part it crooked and ugly and then do the back work to finish.

 

[Wreck™Wreck]

I've seen this happen when the blade is not precisely vertical in the holder. Even if you get the blade perpendicular to the work it will steer and cut a curved path. Are you using that Shars blade with the chip groove on top? If so, be sure it is ground square across the face and is very sharp.

Not actually true, many parting tools are ground at an angle in order to leave the least collar on the part that comes off.

As seen here http://www.iscar.com/Products.aspx/CountryID/1/ProductId/397

 

[umahunter]

I bought a parting block like in the pic from shars it has greatly helped