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Looking for a flycutter

Spyderedge

Titanium
Joined
Aug 28, 2013
Location
NY
Hey forum, I am looking for a medium sized flycutter for my bridgeport.
I have used an adjustable boring bar in the past for a mini flycutter, and I have to say it worked GREAT, but the little replaceable cutter broke
so I might as well get the right tool.

It needs a 1/2" shank,
Preferably HSS (never has experience with carbide, and don't want to take a chance. Plus I can sharpen HSS)
Mainly for aluminum, and steel.
~~No forum trades or buys~~

Thanks!
 
I now check on Amazon.com for everything. You can compare on several sellers and can compare prices and see the feedback from other buyers. Just keyword fly cutters. Good Luck. Rich. Or if you have a lathe and mill you can make one. It's easy.
 
The flycutters I mostly use take standard square lathe tool bits of various sizes. The bits can be HSS or brazed carbide, or, in larger size slots, carbide inserts. The flycutter will take any bit that fits, so it does not make sense to ask for a HSS flycutter. I have a number of them with round 1/2 and 3/4 inch shanks and one with a solid R8 shank. Here are some on eBay. http://www.ebay.com/itm/BATCH-OF-4-...175?pt=LH_DefaultDomain_0&hash=item19e0fff10f Larry
 
We simple drilled an angle hole through a large diameter bar stock or a bar with a larger diameter end at 30 or 45 degrees angle to hold the bar in a collect and drilled a couple holes for set screws so we could change to HSS or carbide lathe tool bits as needed. You can cross drill the same bar, drilling at 30 and 45* so you can have two different cut circle diameters.

The drill hole held the tool bit just fine with the two set screws holding the bit in place.

We use mostly 1/2 but also 5/8 and 3/4. The 3/4 had best strength to extend out for a larger circle.

We also made our own end mill cutters with a 1 inch dia x 4 inch long round with 1 1/4 or 1 1/2 sq x 3/8 carbide silver soldered in a slot then ground for OD and end clearance to make a straight flute end mill that would through .030 x 1/4 inch chips like bullets coming out of a machine gun. The chips came off red hot so anything in range was in danger including me.
 
Just a little advice. Use a flycutter sparingly on a BP, not the best thing on a BP spindle. A lot of guys have them because they're cheap, but they will take a toll on the head.
JR
 
JR is spot on, flycutter will beat a "B'port head to death, especially in low-range. You'd be much better off with one of the little 45 degree high rake facemills that Ekenna sells.

You can get away with a flycutter on something like an old K&T 2H vertical (aka "Klunky and Trecherous") on a B'port...... not so much.

For occasional use and dollar spent, you'd be better off with something like a Criterion boring head. A boring head will do fly cutter duty...... a fly cutter makes for a lousy boring head.

Cyclotronguy
 
My preference for a flycutter is the type that Bridgeport actually built for their machines. I agree that flycutting can be a little tough on BPort heads, but I view a flycutter as a finishing tool, not a stock removal device. The advantage of the BPort-built type is that they have a lot of mass, which helps even out the interrupted-cut action. The one I have is about 4" diameter, with the tool holder receptacles broached vertically at +/- 5 degrees and also straight, 3 pairs diametrically opposed. The tool holder disk is about 1.5" thk and mounted to an R8 shank. You can use one tool for cutting and install a second one for balance, or try getting them both set up to cut. I'd include a pic but I don't have one handy, and doesn't look like any on eBay right now.
 
Help Needed!

I picked up one of the BP fly cutters described above on eBay (4" diameter, with the tool holder receptacles broached vertically at +/- 5 degrees and also straight, 3 pairs diametrically opposed). I've searched but can't find information on this type of fly cutter.

Can anyone point me to the correct way to grind the cutters for this type of tool?

Looks like this except it is 4" in diameter.
https://www.shophardinge.com/product.aspx?partNo=BP 12310001
 
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In a nutshell, without snark intent, it is completely dependent on the material you are machining. Obviously, the tool's cutting edge has to be facing the right direction for the spindle rotation, and you then need to grind the cutting geometry to suit the application. It's not difficult, and there is a lot of room for flexibility and trial and error. Just don't expect perfection 1st time out of the box. The YouTube resource is a good place to start, and get a book about toolgrinding if that isn't enough.
 
A shell mill can simply be used with one insert. At a shop if people are seen using flycutters they are money ahead each few weeks to collect the people doing it and take a half a day for a "deprogramming and reeducation class" and show them proper methods and above all the shell mill with one insert must be shown because fly cutters will NEVER be able to be totally eradicated. In the class and then out in the shop the people have to SEE the correct methods and be forced to use them for a few times and get perfect results to be set free of the old classic homemade flycutter addiction. If people are not in a shop setting and in a home setting I have seen cases where they NEVER got over it and used flycutters till death.
 
OK, since this thread got resurrected I will put in my 2 cents.

If you need a (smaller) flycutter for whatever reason (ours is visual), Tormach (I know!) makes a nice little kit.

TTS Fly Cutters

If anyone knows another brand that is similar please share.
 
I agree with Richard, Amazon is a good/best source for HSS tool bit fly cutter.

Here an ebay 3 set for $20 with free shipping ..How can they do that? USPO box shipping likely cost $7 or more.

1/2'' Shank 3/4'' - 1-1/2'' Fly Cutter Set Cutting Milling Hardened Tool Bits | eBay

Priority Mail | USPS

Amazon
https://www.amazon.com/s?k=mill+fly...x=mill+fly+cutter,aps,168&ref=nb_sb_ss_i_1_15

If you actually had those in your hands, you could see how they can do that;-) All surfaces 250 RMS finish, except the shanks which get down close to 125 RMS, shank diameters with "aspirational" tolerances of +/-.002, cutter seats flat and square to .010 (maybe), and finish off with 65 cents worth of wood and Rc17 hex wrenches. Bargain!
 
I have seen cases where they NEVER got over it and used flycutters till death.

I use fly cutters all the time. This flycutter misinformation is put out by people who either don't know what their talking about or have never seen a Bridgeport.

I use a BP multiple hours a day 6 days a week, I bet my BP has more flycutting hours on the spindle than most BP 'experts' have total on their BP spindles. Guess what, it's still running just fine.
 
I use fly cutters all the time. This flycutter misinformation is put out by people who either don't know what their talking about or have never seen a Bridgeport.

I use a BP multiple hours a day 6 days a week, I bet my BP has more flycutting hours on the spindle than most BP 'experts' have total on their BP spindles. Guess what, it's still running just fine.

Yep, used them for over 20 years. Never seen a BP spindle go bad because of just the fly cutter. As for finish, that all depends on how their used, ie speed, feed, depth of cut, etc. We had many different sizes, from 3" to 12" with cemented carbide inserts. Still have a few laying around here not being used. Went to CNC 25 years ago with a shell mill and never looked back.
 
If you actually had those in your hands, you could see how they can do that;-) All surfaces 250 RMS finish, except the shanks which get down close to 125 RMS, shank diameters with "aspirational" tolerances of +/-.002, cutter seats flat and square to .010 (maybe), and finish off with 65 cents worth of wood and Rc17 hex wrenches. Bargain!

And they work just fine and can finish down into the 10s or even less RA if the toolbit is ground right.
It's a single point tool. These things do not have to be precision made to work.
Yes they are about as fast as watching paint dry in use but handy to have around for weird stuff.
Wonder how people recut or redress table tops without one.
Bob
 








 
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