Those e-bay ones look a bit bargain basement, you would pay more than that for five mid range replacement tips.

I tend to use HSS when I flycut, only a quick touch on the grinder and its sharp again.

I've never found the top rake as supplied to give problems in steel and I used those type of tools quite a bit in the past before Indexable cutters became more common, I still tend to reach for them when I want a radius on an internal corner though and a tip does not have one big enough.

Again your problems may just be down to quality of teh carbide, a single 10mm tool from say J&L will set you back half the price of that set of 11.

Again I have not had problems with carbide and intermittant cuts, lets face it there are many carbide face mills and indexable endmills about and all the tips on those are getting intermittant loading. There was an interesting post about it on Madmodder the other week which relates to flycutting with carbide.

And here is a brazed tipped tool cutting rectangular steel bar on my lathe with the supplied top rake

Edited By JasonB on 06/02/2013 16:39:03

This business of carbide tooling comes up all the time, one thing is that carbide tooling needs a 150% speed increase to cut properly and it must be a good cut. No fine cuts as it will give a poor finish so adjust the tool and work diameter to be very near finished diameter and leave slightly raised steps for bearings and finish those parts with HSS tooling. carbide tooling will remove metal very quickly and save time but only if the lathe/mill is rigid.

Cutting steel with carbide, will if cutting correctly, give blue swarf and its very hot as I have lots of burns on the backs of my hands to show for it.

Also bear in mind that there are different grades of Carbide tips, like P and K which seem suitable for normal work. Unfortunately people see, 'Carbide' and jump straight in thinking its magic and it is not as it requires some knowledge of the types available.

In general, 'Cobalt' tooling is quite adequate for model engineers and Carbide will only be needed occasionally for very hard applications like turning down a milling cutter shank.

Drill shanks are sometimes turned down to fit collets or chucks when you want a large drill but no holder to fit it in. In this case carbide will give a very smooth finish and aid the grip of the drill and chuck.

Clive

Rod,

I though that the analogy between flycutting and milling was a good one, but may be not? I'm curious as to what conditions you're using for flycutting in terms of speeds, feeds and depth of cut. I assume that by 'tooth loading' you mean chip load, ie, feed per tooth?

Regards,

Andrew

I recall Tubal Cain did a lengthy comparison of flycutting and milling. In short he reckoned that to get comparable results flycutting was slower due to lower rpm and feedrates, despite the much larger sweep. He did point out that fklycut surfaces generally LOOK better even if they are technically the same roughness average.

Neil

Stuart at the risk of sounding stupid, and that's not difficult for me, why are you bothering to fly cut such a small piece? I wouldn't bother with flycutting except on a large flat piece. I think that your description of a mini-lathe mill may actually say it all, particularly after reading your comments about using a Bridgeport in another life. All the talk about HSS v Crbide tools is OK but probably will not solve your problem, particularly as your milling head "tilts"during a light load cutting process. Other opinions are available of course. HTH.

Can you not do it in the 4-jaw on the lathe?

Click for Magpie's Flycutter

J

Edited By JasonB on 06/02/2013 21:13:07

Just out of interest how much are you trying to take off per pass?

J

Andrew,

Most of my flycutting experience is on cast iron and I have not done any for some time, I would always choose to end mill these days. When I was young and impatient I guess I would have been taking a 10 or 20 thou depth of cut to get below the skin at about 3 inch radius and probably increasing the feed by 10 thou at each revolution in back gear. Brutal stuff that would not quite stall the Super 7. Each revolution would certainly start with quite a bang that would eventually lead to complaints from the household authorities. I can feel my ears ringing just thinking about it.

Clearly modern carbide inserts are much better at dealing with these sorts of conditions than the cheap brazed tools I tried and I'm sure a big rigid mill can give these sorts of feeds per tooth on a face mill but not in the amateur workshop.

cheers,

Rod

Thanks for that Michael, ( and Jason ) but i do'nt even know what a URL is !!!!!!!

Cheers Derek.

When you get it just right with carbide, even an intermittent cut whispers

Amazing amounts of material are effortlessly removed with a straight cut, it hisses

Watch that swarf though, it can be hot stuff

It's well worth the effort to learn, carbide is now always my first choice for those bigger basic jobs

Edited By Ady1 on 07/02/2013 00:08:48

Sorry Derek … I shouldn't have assumed TLA-awareness

<TLA = Three Letter Acronym>

<URL= Uniform Resource Locator>

… which is the "proper" name for the web-address that you should see at the top of your Browser window.

If you need to know more, please send me a personal message

[click on "Message member" at the bottom of this post]

Hope that helps

MichaelG.

Edited By Michael Gilligan on 07/02/2013 20:46:30