having issues with small vanities moving on CNC when fingering a sink cutout

[quartzworx]

We are only 4 months into the CNC world, with a Park Titan 2700. We don't have a CNC sawjet yet, so we do all of our sink cutouts with the finger bit on the Titan. With small tops less than 5 feet long or so, we are having difficulty getting good enough suction on the pods. The top is moving as the finger bit is cutting. We use as many pods as we can fit under the piece, and we use the edge clamps that mount to the pod. It's happened on both quartz and granite.

To answer the most obvious questions;

yes, the table and both sides of the pods are clean and wet.
yes, we have good connections on our air lines.
yes, we have at least 21 psi of vacuum pressure
we have slowed the cutting speed down 50%
we are using Blick pods
still moves with a new finger bit

If you've had this problem, and solved it, I'd love to hear from you.

Darin H.
Quartzworx

[mikedean]

make sure pods are clean and manifolds are working good.
Most likely, your finger bit is 'pushing' and not cutting. Make sure correct speeds and feeds for that bit.
worst case, 'block' in the vanity with other scrap pieces on suction pods around the vanity.

[tim farr]

Most likely, your finger bit is 'pushing' and not cutting. Make sure correct speeds and feeds for that bit.
[

This and sometimes I will step cut sinks. Make it in 2 passes

[Andy Ross]

Check feed and speed first. Then switch to green pods.

[quartzworx]

Then switch to green pods.
[

do the green pods hold better? have you used Blick also, for comparison?

[quartzworx]

make sure pods are clean and manifolds are working good.
Most likely, your finger bit is 'pushing' and not cutting. Make sure correct speeds and feeds for that bit.
worst case, 'block' in the vanity with other scrap pieces on suction pods around the vanity.
[

I understand that the bit is pushing the piece. Thats the point of my question. And we are at the correct speed for the bit.
I like the idea of making the block. We'll try that. Have you ever used the pod "fences"?

[mikedean]

No pod fences here. Change the bit. Try a different bit. You're is glazed probably.

We never have these problems anymore. We use ADI gold finger bits on EVERY material, 12"/min for all sinks. no movement, ever.

Also, step on the piece to make sure it's sucked down!

[Andy Ross]

Then switch to green pods.
[

do the green pods hold better? have you used Blick also, for comparison?
[

Yes I have owned and used both. Green pods are superior in every conceivable way. There is a major improvement in holding power over blicks.

[wkluender]

Seeing as you are new to the CNC world, "correct speed" varies. My last machine could only run a few of the smaller diameter finger bits reliably, and at about 70% of the catalog speeds. When I'm greater than -25 psi on my intermac I'm watching the finger bit and super z like a hawk. We consistently run 28-32" tops without movement and no fences. Pod setup plays a big role. Try putting a pod, or a larger pod under the cutout. Also, you need to slow your rpms if you're dropping your feed in half or you WILL glaze the bit eventually. For what it's worth, I run 3 different Terminator finger bits depending on the material, all at different rpms and feeds.

[ThomasGraniteTopsIRE]

Is the top moving on the pods or are the pods on the table moving?

We use mechanical clamps as well as suctions on all of our tops except edged islands. If you’re set up already with block pods I think I seen they had a clamping pod which could be worth investing in.

I’ve found running finger bits too slow can tend to glaze them quicker. Also make sure RPM rate is correct.

[quartzworx]

No pod fences here. Change the bit. Try a different bit. You're is glazed probably.

We never have these problems anymore. We use ADI gold finger bits on EVERY material, 12"/min for all sinks. no movement, ever.

Also, step on the piece to make sure it's sucked down!
[

Thanks for your input. That's very helpful. Among other things, I'll try that finger bit.

[colin]

We have the same issue. Always have. New bit blue bit gold bit whatever bit.When sinks are near the outer edges of the counter we dont get enough vacuum between the pods and our top to hold it in place. The pods to the aluminum table never move. We clamp the 4 corners of the stone to the pods using c clamps that are olow enough for our cnc to run above. Once finger bit is done we remove the clamps to do the profiling.

[oatesgranite]

Andy, do you polish on the green pods? We always have more vacuum than that and very rarely have anything move using Blick pods, are the seals in good shape.

[T.J. Henderson]

Wes brought up a great point:

Are you running a pod underneath the cut out? We always place the biggest ones we can on the cutouts of vanities because it can make a big difference.

Also if we can not some of the bigger pods on the top we end up blocking it in like Mike said. Basically set the top in the machine, then place 4 pods around the corners with some scrap pieces set up on it to hold it in place.

[Andy Ross]

Andy, do you polish on the green pods? We always have more vacuum than that and very rarely have anything move using Blick pods, are the seals in good shape.
[

Yes, full polish. Minimal problems with green pods.

[Ken Lago]

Replacing the seals on my Blicks made a world of difference.

[Todd Luster]

Box small tops in with a few scraps on pods while fb is cutting.
Only take a few minutes to do. No programming needed for it.

[Dan Dauchess]

Box small tops in with a few scraps on pods while fb is cutting.
Only take a few minutes to do. No programming needed for it.
[

Poor Mans Fences! We do this when we've got a bunch of small vanities and not enough fences.

[bocephus]

I run Blick pods and like them....I don't think there is a consensus on which are better. Yes the Blicks arent perfect by any means but neither are the "green pods". I run a 15 year old Northwood with a table that badly needs milling and I don't have suction issues. The fingerbit glazing and pushing is most likely part of the problem but also the size of the pods you use could also be an issue. I try to use only 500x250 pods when possible...not only is it less wear and tear on your operator and you get quicker table tunrover, you also have more pod area touching stone per piece. When i first started I had tons of the 200x200 pods and I had issues nonstop with pieces moving...no longer.

Also, I wouldnt invest in a fence but clamp....they hold small vanities in place extremely well.

[quartzworx]

Wes brought up a great point:

Are you running a pod underneath the cut out? We always place the biggest ones we can on the cutouts of vanities because it can make a big difference.

[

We haven't tried that yet. We'll give it a go. Thank you

[Camzl1]

Part of your problem may be science. I looked up your company and found one in Colorado. Altitude may negate you to running a smaller diameter finger bit that is a softer bond and slower feedrate to reduce the cutting pressure. You will lose life but not pieces. I wouldn’t run anything larger than a 20mm fingerbit like our Terminator G5 40mm length bit or FB15820 red bit. Adding a couple of fences or BVC cups into the mix will definitely help. If you need any of these items we at Terminator can help also here too.

[Solid Rock Oregon]

I see this problem as over all surface area. the surface area is too small to stay in place when the sink is being cut. I will use some old rectangle shaped sink drops and place them on suction cups/pods around the outside of the workpiece. add a stop in your program after the sink cut to remove the drops and pods. this has worked well for me..

[Solid Rock Oregon]

IMG_20190508_142853.jpg (147.54KiB)Viewed 2429 times

[faster]

found this.....prob wouldn't recommend only 3 cups, 4 would make me feel better, but i do like no fences and way faster setups!

https://youtu.be/ILNd9Ns2dnw, might take a day for the video to publish so be patient

[faster]

ok video is working, sorry for the delay