New Fly Cutter

[TorontoBuilder]

I feel that newcomers to the hobby can often be given more information than they need and can be put off by over complication.
If I offended you then I apologise.
Dan.

I'm an adult tech educator in the building science field, while I concur that during a training sessions there are limits to how much students can absorb at any one time, permanent online resources are just that, permanent resources that can be accessed once or as often as necessary until the student grasps the lesson. Therefore its beneficial to have the lesson include machining best practices.

Therefore, I find that its far preferable to provide detailed best practice references. How ppl structure their posts and how you link to material is what will keep it interesting and on a level that all forum participants can enjoy...

So Luc, thanks for the detailed fly cutting angles... I'll make use of them

 

[abby]

Ah well , think I'll go back in the workshop and make some swarf !

 

[Tin Falcon]

I'm an adult tech educator in the building science field, while I concur that during a training sessions there are limits to how much students can absorb at any one time, permanent online resources are just that, permanent resources that can be accessed once or as often as necessary until the student grasps the lesson. Therefore its beneficial to have the lesson include machining best practices.

Therefore, I find that its far preferable to provide detailed best practice references. How ppl structure their posts and how you link to material is what will keep it interesting and on a level that all forum participants can enjoy...

So Luc, thanks for the detailed fly cutting angles... I'll make use of them

Very well put. While not currently a professional teacher I too have had training as an instructor and have held instructor ratings in the past as well as helping run the place here for 7 years. I too believe in giving the basics and then giving resources to find more info when it is needed and or desired.

So there is a place for the technical references and the KISS methods.


What I do feel is a distraction to learning here is the petty arguing, one upmanship attitudes, and the childish my way is better than you way attitudes exhibited by certain members. There is nothing wrong with book data or this is the way that works for me. As long as the methods procedures and info are safe. there is room for varied perspectives. let the new guy try things and find what works for him or her. Show respect for other views.
People want clear answers not a debate between a couple of seemingly old people full of smelly air.
Tin

 

[abby]

I would hardly describe some one having a different approach to a topic as "one up man ship" or having an argument simply because they post what they think.
Make up your minds Do you want members to post or not ? I do not post often because if someone has answered the question to it's fullest I have nothing to add, unlike many who insist on repeating what has already been said or starting with "well I don't really know but "
If I think that a post can be expanded then I will do just that , as did the other guys , if that is argumentive then what are we allowed to post.
Quite frankly I find your "it's my ball" attitude very typical from your side of the atlantic , and for all the guys who claim to be college lecturers , teachers or training officers of other description, we have a saying here "those who can do ! those who can't teach!".
I have better things to do with my time than waste it here.

 

[canadianhorsepower]

with all due respect enjoy it where you want to
but respect other's opinion

:fan:

 

[Swifty]

I must have missed something on this topic, I haven't seen any petty arguing at all, just different ideas. That's what I find good about this forum, members can post their ideas without fear of being shot down.

Theory and charts for clearance angles are great, thanks Luc, but there comes a time where the end user is confident in their approach to be able to grind tools freehand without resorting to using protractors etc to check angles. Of course, the novice is nervous and needs all the help they can get, which they do get here.

Paul.

 

[Omnimill]

It's a shame this thread has degenerated but it's by no means unusual on Internet forums. There are many "experts" out there but readers would be wise to treat any information given with some scepticism until they can confirm safety or suitability for their own particular purpose. This should go without saying but there you go, I've said it anyway just to be clear.

Much of the "data" for the tools we hobbyists use today and repeated ad nauseam even in new publications comes from books written in the late 1800's or early 1900's. This "data" came from practical experimentation by machinists. Anything that worked well was noted and passed by word of mouth or written up in the journals or books of the time.

I have a number of old engineering books in digital format and by far the most information about tool bits is centred (pun intended) around Lathe tools and to a lesser degree tool bits for Shaping machines. There is precious little about fly cutters for Milling machines. I'm sure I could find the odd page or two if I looked long enough but I'm sure you'll forgive me for not wanting to spend the time trying.
If I missed something really good out there though please let me know.

I'm sure you'll agree that pressing a fixed tool against a rotating, largely cylindrical object is slightly different to traversing a rotating tool against a fixed flat object.

It was said earlier "I did supply the "proper information". And someone else called it "published" (data), "book data" and "we should follow convention". Good idea, I'd agree with that. I had a look to find this "proper information". Even now 99% of the information on fly cutters seems to be on forums so it's not surprising I found this link which shows where the Fly cutter drawing posted earlier on here appears to originate, post #7:

http://bbs.homeshopmachinist.net/threads/40978-Fly-Cutter-Cutting-Tool-Bit-Geometry

As the guys says: "Here's an image I edited from one on Wikepedia". And "I edited the surface names in the image to make it more appropriate for a flycutter".

He then gives a link to the original Wikepedia page where he got the image:

http://en.m.wikipedia.org/wiki/File:Tool_Bit_Geometry.JPG

I tried to find the other image listing rake angles for different materials but failed to find it. I suspect though it's just one of many charts used over the years for Turning tools.

Anyone can cut and paste "data" from the internet, it doesn't mean it's valid.

Abby, Swifty and I all appear to be using very modest angles on our fly cutters with what seems to be complete safety. I've certainly not had any safety issues like chipped cutters etc and the finish I get is very good - have a look at my Tangential tool on here so many have said they like.

I would be very careful using some of the rake angles suggested by the chart posted earlier. Judging by the comments I've seen on some other forums greater angles can cause the tool bit to move down during the cut damaging the workpiece. In the worst case scenario the cutter could come out of the machine.

Abby, Swifty and myself have all been told we're doing it the wrong way. Which is fair enough, everyone is entitled to their own opinion. It's a shame though that some have resorted to mild verbal abuse to make their point. I'm sorry you have so many "seemingly old people full of smelly air" over there. It's not a problem we seem to suffer from here though. That was meant in jest in case you were wondering...

I'm in the middle of refurbishing my old bench drill and only posted on this thread originally while I was waiting for the paint to dry on some of the parts. I won't be spending any more time on this thread though so if you want to abuse me further you best do it by PM. Don't expect a reply soon though as I'm near to the exciting part of putting my drill back together. Can't wait to see how quiet it is with the new bearings! I'll post pictures on the "other" site if folks want to see it.

 

[TorontoBuilder]

please Austin add an option to dislike posts as well as like. when people feel the need to denigrate the sharing of info it turns people off more than having to read what may be old info to some...

 

[Blogwitch]

A lot of people have mentioned the flycutter shape that I showed many years ago.
Even though I am now coming to the end of my model engineering life, I have still not found anything that can beat it for performance and quality of finish, and I use it even when I should be using normal cutters for mass material removal, all because the surface finish it leaves behind is fantastic and I can very easily machine with it to a tolerance of a couple of 10ths.
One thing that must be done, and not just for flycutting, is that the spindle should ALWAYS be in perfect tram with the table, and so the piece part. Without the machine being in perfect tram, you may as well use a hacksaw to attempt to shape your piece part.
This tool cuts so smoothly, even at depth, I have never had the tool lift more than a couple of 10ths while in action and have never had it dig in or move in it's holder.

Here is a slow motion video of my cutter in action, showing even at this cutting depth, the surface finish left behind was a lot better than most people can obtain when trying for a good surface finish.

http://youtu.be/FipAdIUr5OE

BTW, about 50 years ago, as I was breaking in my first pair of safety boots, I worked with an old codger, with wrinkles all over his face and skin on his hands that could be used to make a crocodile handbag.
Well one of the first things he told me was to disregard all those know it alls who blow formula out of their rear ends (tidied up to make it internet safe) and listen to the people who actually work on the machines, they have already tried and discarded everything they have had to say or show and come up with methods to get the job done quicker and safer than they (ass blowers) could ever dream or come up with.
It was a man like that who first showed me the flycutter shape that I use, and it has never failed me yet.

John

 

[Swifty]

I went back and reread all the posts, strange thing, the brazed tip cutter that I have been using for years has zero top rake, exactly as shown in the chart (bar one with negative rake), this was without reference to charts.

Another thing that no one has mentioned, some of the angles will vary depending on the angle that the toolbit is held in the cutter body.

When running my toolmaking business, when we tried out a new style of facing cutter, of course we had to use all speeds and feeds that were recommended, eventually we either stuck with the data or altered it to suit ourselves.

Maybe I'm one of the old farts, but it comes from many years of practical experience in a toolroom, and I certainly was hands on all the time. I have trained about a dozen apprentices, and some even won awards at trade school for their practical and theoretical work, that ability was not solely gained by their one day attendance at trade school per week, but by being trained by experienced tradesmen at work.

Paul.

 

[Tin Falcon]

Swifty you are correct there is value in book learning and reference material and hands on experience. Best practice is going to vary based on the tool the machine , material being cut , lubricate or lack thereof.
Tin

 

[canadianhorsepower]

I'll post pictures on the "other" site if folks want to see it.

Thats the best news today.:fan:


Now remember that LONG LONG LONG.... LONG time ago machinist were using granite to cut steel......................................practice have change..............how about reading books of 2014

stuff have change like it or not:wall::wall::wall:
I just hope that some older peoples attitude want get new members to go away My answer did please the person asking for help
like it or not

 

[Swifty]

Quite right Luc, I employed several tradesmen over the age of 60. They had the experience, which was fine, but I made it quite clear that I didn't want to hear "I'm my day, we did it like this". I was in business to make money, so modern materials and methods were critical.

Paul.

 

[Blogwitch]

Quite right Luc, I employed several tradesmen over the age of 60. They had the experience, which was fine, but I made it quite clear that I didn't want to hear "I'm my day, we did it like this". I was in business to make money, so modern materials and methods were critical.

Paul.

Unfortunately, this and many other sites are beginner orientated, who in the most part can't afford the latest wizz bang, blow it out of your a** bits and pieces that keep the wolf from the door when in a production environment.
All they require is good first class information to make good results within their reach and budget, and showing them the latest trade catalogues will do them no good at all.
I am one of those old pharts who try to pass on good information to the great unwashed masses in the model engineering fraternity, but not only did I look to the past for info, but also to the modern day, which in my view, when it comes to affordable machining in a small workshop, most of the modern stuff just wasn't relevent purely because of cost. What was needed could be done with very small budgets.
I also ran a small production environment, and converted my shop to contain all the latest gizmos and gadgets, purely because it was required to remain competitive. The workshop was onto a winner and large profits were being made, unfortunately the weak link (my own health) wasn't able to keep up, so my high precision workshop reverted back to a hobby shop.
99.9% of all those expensive bits were never used again, purely because they were not needed, I could do everything that was now needed in my shop with old fashioned technology and materials. All those expensive bits are now sitting under the benches gathering dust.

I would suggest to all you beginners, is to go onto the free book download sites and get a few of the many machining books available (usually pre first world war) and you will learn how they did things in the past, and you will also find, most of it is perfectly relevent to what you are doing in your small shops now, and it will hardly cost you anything at all, as in those days it was usually make it yourself for pennies.
Or, if you can, search out an old phart and he/she will overload you with good info to use in your home shop.

John

 

[Tin Falcon]

I am locking this thread . It has turned from a new member asking a question to a debate over book learning published data and off the cuff machining.
Tin