large radius endmill

[kentsui]

I need a 3" radius end mill based on a 1.1875 or 1.25 (1" shank) end mill. My tool maker that normally does the work tried to put a 3" radius on a 1.1875 cutter and can't do it. Can someone tell me who might could handle this for me? My tool maker said he had gone totally to CNC for his grinding and he could get the machine to do that large a radius.
For all I know, there is some stock endmill with a 3" radius at least that large on a 1" shank tool but I haven't found anything.

Any help/suggestions would be appreciated. The job is 6061T6 aluminum.
The cut is very shallow.

Thanks in advance.

Kentsui

[cb1]

i could help you with this tool, no problem, i do this all the time.
there is no stock tool like this, you have to buy the endmill you want to use and modify. i would say a 2fl. hss 1-1/4. i could pass some info to your tool grinder, or make the tool for you. let me know.

[HuFlungDung]

A thought occurred to me that you might be able to emulate this radius with an ellipse. Just playing a bit with CAD, if you took a 1.25" square endmill and tilted the head about 9.75 degrees from vertical, you'd get a useful cutting width of about .968" with a radius of 3.001"

[Geof]

Try finding a woodworking router bit, these are available in an enormous range of shapes and radii. I use them very often for doing corner radii up to 1/2" on 6061 and they work very well. I have even used them on hot rolled steel successfully.

You may need to find a commercial source to get them with a 1/2" shank, most places like Home Depot only have 1/4" shanks and these tend to fatigue and break.

[kentsui]

Thanks Geoff,
I will see what I can find. I was actually looking at som shaper bits last night ( like molding cutters) but holding them would be dicey. I have another need to do a double 45 "blade on the edge of some 6061T6 plate and was thinking of trying that. I didn't think of router bits though. I am only removing about .055 for a length of less than an inch so it really isn't under much stress at all. I can step cut it with a data-flute to start with and have almost nothing for the radius cutter to do so thanks for the suggestion.
Have a good 4th.

Kentsui

[kentsui]

HFD,
Thanks for the suggestion. Unfortunately this is a production job on a vertical CNC with fixtures already built and pinned...but now the customer adds a 3" radius instead of a simpler common radius and its either do the radius with the part flat, or another op to do it on its side. I do appreciate that idea though. We have done that before for rapid stock removal on a long slender part with a radiused bottom and it worked nicely but I hadn't thought of it for this. If it was a one-off I'd do it in a heartbeat.
Kentsui

[kentsui]

CB1,
Could you quote me on it, price and delivery? That's exactly what the other tool man was trying but he gave up. He used to do it all the time so I quoted the job as "no problem" when they added the radius so large. I actually have the new cutter he tried on but he couldn't "fool" his CNC to do it for him. Apparently it isn't capable of the larger radius on the smaller cutter.
If you'd just send me a private message with the pricing I'll get back with you.
Thanks,
Kentsui

[dharschman]

A 3 inch radius on a 1.1875 or 1.25 endmill with a 1" shank shouldnt be a problem at all. Give us a call @ True Cut Tool 937-964-1603 ask for Kendall or Larry.

[Herbertkabi]

3" Ball End Mill, HSS 4-Flute, 1" Shank Item number: 150267859581
http://cgi.ebay.com/3-Ball-End-Mill-...QQcmdZViewItem
US $25.00 , 0 bids
End time: Jul-09-08 16:28:33 PDT (1 day 8 hours)

[kentsui]

Herbert,
Thanks for looking out for me. That is a HUGE end mill!
I appreciate you pointing me to it. For the current problem I have to have a 3" radius ( 6" dia.) but that one is worth having in the arsenal!

Thanks again for the heads-up.
Kentsui

[guru]

very shallow 3.0" Rad in 6061T6 aluminum? .....I'm not sure what the part look like, But what about doing flowline using smaller dia. ball endmill.

[Herbertkabi]

Seems you are building next generation Synchrophasotron or something like that ;-)
Yeah - my mistake - was not observant about dimensions you need, but $25 for this nice piece is not much even it will stay dust-covered on the topmost shelve.
Cheers,
Herbert