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High feed milling on Hurco

lawmate

Plastic
Joined
Sep 15, 2015
Location
London, UK
Hi

I have had a Hurco VM10i for a year and am just working on a mild steel (EN1a) job where there's a lot of roughing material to remove. I bought a 20mm Mitsubishi AJX high feed end mill and am just wondering if it's OK to use. I'm running it to the specs advised, 1mm ap, 1mm fz, 110m/min and I've run it for an hour or so without coolant and the inserts look untouched, but it machines very loudly. The spindle load is 10%, but I can see the Z axis load fluctuating a lot as though it's taking the force of the cut. Also the sheet metal on the machine is vibrating around a lot.

I'm pretty new to machining so am not too sure what sounds ok or not. I don't want to damage the machine but I also want to be cutting heavily. Does anyone have advise on how much I can push using high feed mills without damaging the machine?

I'd prefer to use an insert cutter as I have quite a few pieces to do this roughing on and so will be a lot cheaper than solid carbide. Would a shoulder mill be a possible gentler alternative?

Thanks
 
VM10i is a very light machine, but a 20mm feed mill shouldn't trouble it.

I don't think your cutting data is correct, 1mm ap and 1mm fz would be closer to correct data for the size 14 ajx inserts, and 110m/min is very slow for soft mild steel.

I only have larger ajx tools, all my smaller feed mills are tungaloy and sandvik and solids from Horn. However, I typically run a 20mm feed mill at about .5mm ap and .5-.7mm fz, and I'd be somewhere around 200-240m/min in en1a.

Also, feed mills are noisy when stepover is too small. Ae needs to be around 80% of the cutting diameter for best results.

Also also, the Z axis does take the force of the cut when using a feed mill, so that's another sign that your chipload is too heavy.
 
Your best bet to reduce vibration is to reduce your ap. Greg's recommendation for 0.5mm ap seems spot on.

What color are your chips? If they're not blue, you can spin faster and/or feed harder to make up for the lost productivity from reduced ap.

Be careful when the tool runs up against a shoulder. It does hammer the inserts and the only solutions are to reduce the feedrate or to adjust your toolpath to create a sloped shoulder, which will later need to be cleaned up with a solid endmill.
 
I have worked with a HURCO VM10i for a while and i can confirm that it's not for heavy duty stuff. I have also tried a carbide inserts end-mill and the machine was chasing me around the shop. The highest mrr i have achieved was with a solid 16mm carbide end-mill cutting at full length of the cutter.

Carbide inserts are not as sharp as carbide endmills and require more power and a more rigid machine. That 1mm fz is way too much. Try to reduce the feed rate while machining until you are satisfied with the noise :)

What thickness of sheetmetal are you cutting? Maybe you need better clampling/fixture.
 
Hi all

OK, thanks a lot for the suggestions.

I'm starting to find the limit of the machine in this area.

I'll definitely try increasing the surface speed as the inserts seem untouched at the minute and can definitely turn it down on the ap and fz.

Workpiece is very solid. It's a 50mm thick block clamped down straight on to a steel fixture plate, so essentially flat on the bed. I think the vibration is really just from the machine.

Thanks a lot
 
High Feed mills are generally just loud. They have a very particular sound to them; you can generally tell if one is running when you walk into a shop.
 
We have done a ton of High feed milling on Hurco's and the Mitsubishi rattles the shit out of them. We went over to Hitachi 4 flute and it was much better, and currently use the Kyrocero mini raptors and the purr like a kitten. Throw the 2 and 3 flute Mits in the garbage.
 
We have done a ton of High feed milling on Hurco's and the Mitsubishi rattles the shit out of them. We went over to Hitachi 4 flute and it was much better, and currently use the Kyrocero mini raptors and the purr like a kitten. Throw the 2 and 3 flute Mits in the garbage.

That mini raptor looks very similar in design to the tungaloy dofeeds that are my current favourite.

If you want to talk noisy feedmills, the Coromill 210 is the king of that. I used those for years and they seriously move metal, but you need a 50 taper spindle with a lot of ponies behind it in a machine heavy enough to have it's own gravity if you want to preserve your hearing.
 








 
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