I'm losing my mind over here trying to cut out small letters on my Multicam 3000. I just can't get hold down to release the parts. I'm forced to release the parts via knife and I feel like there has to be a better way. Does anyone else have experience with this stuff? I have no problem with bigger letters, but 3" and smaller, even with final passes of .05" at 30in/sec the part flings out. It's slowly killing me!
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Small PVC Foam Sintra Letters
- Thread starter MDKAOD
- Start date
SignMeUpGraphics
Super Active Member
I don't own a CNC (yet) but is it possible that the bit diameter might be too big for this job, leading to vacuum leak around the letters and causing them to 'flick' out on their own?
SignProPlus-Alex
New Member
30 inch/sec = 1800 inch/min. You may want to slow down. I am using single flute .125 with PVC and my cutting speed is about 125 ipm. Very small stuff have to be tabbed or hold with double sided tape.
fixtureman
New Member
I cut them all the time one way is use a pressure foot. the way I cut the kind like you show is to use 3m 77 to hold them to a scrap piece of sintra or coroplast then just peel them off and wipe them down
That was fried brain speaking. 30in/min.
SignProPlus-Alex
New Member
I learned a trick with my cnc some time ago.
If you cut it at right speed without dust collector on pvc shavings will stay in the kerf and hold your part from moving.
Make sure you make shaving not the dust.
30 inch/min may be too slow.
If you cut it at right speed without dust collector on pvc shavings will stay in the kerf and hold your part from moving.
Make sure you make shaving not the dust.
30 inch/min may be too slow.
Can you let us know how it turned out?
Will do, tooling is due in on Tuesday or Wednesday.
DSC
New Member
I absolutely recommend a double sided adhesive with a waste pice below..
The solid sub surface does not cut all the way through, so it stays in place..
And with material up to 1/2" you can do it in a single pass. your offset anyway..
The letter material is taped to the lower scrap piece and will not move..
Tooling wont help .. Only the adhesive will work.
Obviously and as well a freshly milled table is your best friend..
Bridges
If you have a MultiCam you are more than likely using EnRoute. If so, you simply use bridges. When you apply the route offset. Select bridge along with the appropriate height and length.
I do small letters all the time in our shop. No more that two bridges though.
If you have a MultiCam you are more than likely using EnRoute. If so, you simply use bridges. When you apply the route offset. Select bridge along with the appropriate height and length.
I do small letters all the time in our shop. No more that two bridges though.
I recently did a 2 month "internship" at a shop that had pretty good routers that were not maintained with terrible vac hold down. Here is what I learned.
1. Turn on the vac table no matter how badly you think it's performing. Every bit helps.
2. Cut with a small bit. For smaller letters, 1/8 or 3/16 bit is the way to go. Despite what people tell you, packing the kerf helps a lot with hold down and I never had a problem with rewelding.
3. Turn off/down your vac dust setup. You don't want any more uplift because you're probably already using a spiral up bit.
4. Don't try to run fast. I'd max out at about 120ipm. That was normally done on letters where I was making 2 passes. Most of the time I ran between 60-90ipm, especially when doing 1 pass. The good thing about PVC is you can go pretty deep. Full depth passes on 1/2" material with a 1/8" bit is pushing it a little but 3/16" was no problem. You need HP to do this so if you don't, you may not be able to be that aggressive.
5. This is the key and some might disagree but I can tell you it works pretty well. You need to set your entry points so that you can manually hold down the letters right before the cut finishes. This is very dangerous so you have to be smart about it. It took me about 2 weeks to get a hang of where to set my start points so I could stick my fingers in there "comfortably". That's why setting your entry point is very important. I would never ramp into letters so the exit point is predictable. This is another reason why you don't want to run fast. On 3" letters, I'd probably run around 75ipm. Smaller, I might drop to 60ipm or even less sometimes.
Before learning these techniques I did a lot of what was posted on here. Gluing and taping to a carrier board and cutting. That works very well but after the cutting is done, but it's more costly and often more time consuming. If you're running sheets of small letters, I'd mask, spray adhesive, and put on a carrier board but if it's just 1 or 2 jobs per day, I promise my techniques work. I will admit that there is a bit of waste doing it my way. Occasionally, you'll lose a letter for one reason or another. If you're in a circumstance where you need a perfect run, you're going to have to use adhesive. If you can live with 1 out of 15 letters needing re-cutting, then the technique above works.
1. Turn on the vac table no matter how badly you think it's performing. Every bit helps.
2. Cut with a small bit. For smaller letters, 1/8 or 3/16 bit is the way to go. Despite what people tell you, packing the kerf helps a lot with hold down and I never had a problem with rewelding.
3. Turn off/down your vac dust setup. You don't want any more uplift because you're probably already using a spiral up bit.
4. Don't try to run fast. I'd max out at about 120ipm. That was normally done on letters where I was making 2 passes. Most of the time I ran between 60-90ipm, especially when doing 1 pass. The good thing about PVC is you can go pretty deep. Full depth passes on 1/2" material with a 1/8" bit is pushing it a little but 3/16" was no problem. You need HP to do this so if you don't, you may not be able to be that aggressive.
5. This is the key and some might disagree but I can tell you it works pretty well. You need to set your entry points so that you can manually hold down the letters right before the cut finishes. This is very dangerous so you have to be smart about it. It took me about 2 weeks to get a hang of where to set my start points so I could stick my fingers in there "comfortably". That's why setting your entry point is very important. I would never ramp into letters so the exit point is predictable. This is another reason why you don't want to run fast. On 3" letters, I'd probably run around 75ipm. Smaller, I might drop to 60ipm or even less sometimes.
Before learning these techniques I did a lot of what was posted on here. Gluing and taping to a carrier board and cutting. That works very well but after the cutting is done, but it's more costly and often more time consuming. If you're running sheets of small letters, I'd mask, spray adhesive, and put on a carrier board but if it's just 1 or 2 jobs per day, I promise my techniques work. I will admit that there is a bit of waste doing it my way. Occasionally, you'll lose a letter for one reason or another. If you're in a circumstance where you need a perfect run, you're going to have to use adhesive. If you can live with 1 out of 15 letters needing re-cutting, then the technique above works.
Jester1167
Premium Subscriber
Use a double layer of premask on the bottom side. That way when you cut through the material (and not the premask) you don't loose suction and the mask will hold the letters down. Don't nest the lettering so tight that the kerf overlaps, put space between the lettering.
limacchina
New Member
Double sided adhesive will help.
johnnysigns
New Member
Onsrud 63-76X series tools are our choice for 3/6mm PVC. Follow their feed rates for your given RPM and you should see excellent results with one of the methods mentioned that works for you to hold the sheet down. If you're unsure what feed rates to follow, call their 800 # and talk to someone in tech support. They'll walk you through it.