Newbie Questions..

[Rikk]

Hi guys, hope it's ok here, thought I'd post just once to keep all my dumb questions together, I do search and read as much as possible but there are some things I just need to ask so be gentle ;)

Just getting started in this hobby although I've been interested in metal working and machining for a very long time. I've built a workbench and have the lathe on it with a mill arriving in a few weeks when they get off the boat.

Here's the bench I made, that grinder has now gone and been replaced by a much better one with a 40mm aluminium oxide wheel. The mill will be going where the grinder is now as the workbench will be extending along to the left.



So onto the first question, one of the tools I bought is a Glanze Clamp Type Indexable Parting Tool (http://www.chronos.ltd.uk/acatalog/Chronos_Catalogue_Parting_Tools_82.html) all seems to work fine I'm just a little concerned about the state of the insert after some light duty.
I've parted off 5-6 bits of delrin varying from 6-25mm, a couple of bits of very soft 8mm ali rod from homebase and a 6mm bit of this http://www.wlcooke.co.uk/catalog/product_info.php?cPath=21_46_47&products_id=1330.
All was done at a slower rpm than specified as I'm a big girl and still getting used to things ;)

The tip now looks like this :-



Is the coating just worn off or is it finished?

Totally unrelated but is there a way to get rid of all the smilies when you're posting as boy do they get in the way.

Thanks in advance.

                ............Rikk

[Brass_Machine]

Hi Rikk!

Gonna move this over to the "how do I" section.

But onto you questions. 1st, my that is a NICE parting tool. How is it parting? If it is fine, you should be OK. It looks to me that it is just the coating (or dirty). It shouldn't be that worn after only a few pieces. Someone can correct me if I am wrong.

Hmmm... the smileys. Not sure, I will look in the config and see if can disable them as a user.

Don't worry about the questions... everyone starts somewhere. I still ask newbie questions...

Eric

[sbwhart]

Rikk

That tip looks knackered, did you have it set on centre height?.

Don't be afraid of running faster speeds when parting off, the trick is nice steady pressure and try to keep the chips comming off at a constant rate.

The surface speed of the work over the tool is an important factor but when parting off you're going from a big dia to a small dia so surface speed will go from frast too slow, at some point you'll hit a spot when the tool won't like it, you just have to grit your teeth and wait for the point to pass or change speed.

Keep the tool set close into to the tool post to give less overhange and part off close to the chuck so that everything is nice and ridged.

Hope this helps

Stew

[Rikk]

Cheers guys, thanks for the pointers.

Fair enough I'll crank up the speed and grow a pair ;)

I just checked the centre height and at most it's .5-.25mm out but I've been tweaking thinks as I go so it might not of started off so close.
I understand why having it spot on is needed, but why if it was over or under a bit would it wear the tip?

I'll swap over to the HSS part off tool till I get the hang of it a bit more or it's going to get expensive on replacement bits ;)

I'll invariably have lots more Q's as I go so I'll pop them in here save lots of posts.

                ..........Rikk

[75Plus]

Rikk, Just a suggestion for finding the center height. Lightly pinch a pocket size 6 inch steel ruler between the work piece and the tool bit. If the top of the ruler leans toward you the bit is too low. If it leans away it is too high. When it is truly vertical it is just right.

Hope this helps.

Joe

[Rikk]

Cheers, I'll give that a try tomorrow. What with my eyesight not being great and the lathe fairly small anything helps 8)

Rikk, Just a suggestion for finding the center height. Lightly pinch a pocket size 6 inch steel ruler between the work piece and the tool bit. If the top of the ruler leans toward you the bit is too low. If it leans away it is too high. When it is truly vertical it is just right.

Hope this helps.

Joe

[raynerd]

Rikk
Interesting post since I also have a parting tool which seems to take the identical insert. I also find that after light use mine gets the same look as shown in your post and is useless. I paid £30 for my parting tool and have hardly made a cut with it. I concluded I must be parting/using it wrong so decided to grind up my own tool from HSS and have had much more success with this. I`m still very much learning in this hobby and would be interested to see if you start cutting more successfully with it and what you change to do so! At the moment it hasn`t been on the lathe for about 6 months!

[kwackers]

From the photo it looks like a build up of material rather than wear. If you look at the top of the tip there's a ledge (i.e. it's higher than it should be).
Probably just down to machining soft materials, you'll probably find it'll clean off or if you part some steel it'll remove it...

[Rikk]

That's what I had assumed initially as it did look like some ali had built up on it so I parted off the bit of steel listed and now it looks like this.

A new one looks like this so it could be the coating just come off but is the coating meant to wear off?

From the photo it looks like a build up of material rather than wear. If you look at the top of the tip there's a ledge (i.e. it's higher than it should be).
Probably just down to machining soft materials, you'll probably find it'll clean off or if you part some steel it'll remove it...

[Bernd]

Inserts that are coated with that material have a tendency to pick up the color of the job your cutting.

I would recomend a HSS tool for such a small machine since carbide is made for a much sturdier machine.

Bernd

[Reckless_Engineer]

Looks like the tip has been rubbing too much to me. Carbide inserts really like to work and carbide parting tools really cut best going like the clappers!

I have only ever used carbide parting tools at work but i find on a smaller lathe the ridgidity isnt there to allow them to work how they want too. Id go back to Hss see how you get on.

[kwackers]

Once the coating wears off the tool is usually cabbaged. I don't know about that particular tool but I use the excellent Kit-Q-cut from Greenwood which looks very similar.

You don't actually say in your OP that you've had any issues parting off just that you were concerned with the condition of the bit, if this is the case and you're not experiencing any problems then I don't think you've got much too worry about.