core hole blowout

[btimike]

We are encountering a few blowouts on our titan fabcenter the bit we are using seems to glaze almost right away after dressing this has only happened on harder stones and india granites we are using an orange bit from granquartz that came with the machine, and have now switched to a terminator blue which is working for now, mainly just interested in others experiences/solutions to this? feedrate is 2"min and 5000 rpm and have played with it both ways with similar results. thanks in advance.

mike

[tim farr]

2" a minute is wayyyy too slow

[Jqualey4130]

5000 rpm is way to fast for 2 imp. Try 2200 at 2 imp. The 5k is glazing your bits.

[Camzl1]

Hey Mike

The parameters for the blue zoom is: 2"/min @ 2200 RPM
5-6"/min @ 2700 RPM
10/min (engineered stone)

If you are drilling all the way through then best to have a sacrificial pad like the one from Blick to prevent the blowouts

[btimike]

sorry, it was 2" @ 2000 rpm staying an 1/8th from surface and knocking them out on site, should it be faster than 2" a min? i used to core holes manually alot faster but didn't think that was relevant.

[Steve A]

If you are drilling all the way through then best to have a sacrificial pad like the one from Blick to prevent the blowouts

And if you are not drilling through be sure to have a pod underneath your drill point anyhow, this will also help with blow outs.

I went through a couple core-bits in a very short period of time. Blowouts and melted bits... Turns out we had internal water issues. On our Intermac the valve just above the spindle head scaled up and was starting to stick. I was getting little to no internal water at times. With the external halo pumping out so much water I did not notice. It doesn't hurt to check your internal water flow and make sure its not restricted.

[Camzl1]

Hey Mike

Yes you can drill faster. If you are still on your big project then go 5"/min at 2700 RPM. This will help with the times from 45 seconds a hole, assuming 1.5" travel which includes safety clearance when the machine starts the feedrate drilling, to 24 sec a hole.

I want to add. I have also had the problem of too much water pressure and the combination of leaving .1 to knockout that the water will blow out the hole. So if you want an absolute of not blowing out then use a sacrificial pod underneath.

[BellaRocha]

I was once told to drill some small holes in the side of the core bit to allow water to escape. I've found blowouts depend mostly on the material. Also a pod underneath helps.

[btimike]

Thanks everybody for the reply's i think the new bit is better but I am pretty gunshy on drilling faster as this problem has cost me a thousand or two already i think i will go with the sacrificial pod idea and drill all the way thru, damn this beast is hard to tame...

mike

[Matt Lansing]

Don't drill all the way through!

You will still get a blowout even with a pod there if you try to drill all the way through. Having the pod underneath will significantly lessen the chance of a blowout but you need to still stop short of the face.

[btimike]

Matt, have you tried the pods eric is talking about? I'm just trying for a be all end all to this.

[Carmine Pantano]

Our drill bit stops at about 1/16"-1/8" before the bottom and we ALWAYS put a vacuum pod under it. No blow outs. If too thin for a vacuum pod, we use the Blick Drill Bit Pod.

[Todd Luster]

Our drill bit stops at about 1/16"-1/8" before the bottom and we ALWAYS put a vacuum pod under it. No blow outs. If too thin for a vacuum pod, we use the Blick Drill Bit Pod.

Ditto.
We just drilled over 500 holes in the last month and a half for a commercial job in 3cm Breccia Sarda marble. No blow outs.
We have never tried anything but Terminators bits, as they have worked great for us. I will post the speeds and rates later.

[badboat]

We stop the same as Carmine. Tyrolit blue core bit 2500rpm feed 1.5.