I have been using the TwoTrees TTS-55 for a few months now and I have been engraving and cutting 3mm pine plywood with no issues.
Yesterday I got my hands on 4mm pine ply and I cannot for the life of me get it to cut through.
I may be way off the mark here, so if anyone can help me out it would be greatly appreciated.
This is what I have tried so far.
Top of Focus Block:
(S)Speed: 100
(P)Power: 100
(C)Pass Count: 1
(S): 100
(P): 100
(C): 2
(S): 200
(P): 100
(C): 2
(S): 200
(P): 100
(C): 3
(S): 300
(P): 100
(C): 3
(S): 300
(P): 100
(C): 4
Third step of Focus Block:
(S): 300
(P): 100
(C): 5
If you wish to cut thicker material than before you need more power…
Either by increasing the percentage power of slowing down the head. You’ve seemed to increase speed … Don’t know what happens if you set the speed to zero… didn’t think you could do that…
It’s always wise to mention the units you are using… mm/m is common with dpssl lasers, but so is inches/m or mm/s.
I set all of my machines to mm/s, I’m used to seeing it scan in that unit. Doesn’t matter which, but it’s good for people to know when trying to answer.
The lowest speed I went was 90mm/m (just noticed the typo) but all that ended up doing was burning the top of the plywood and it still did not cut through unfortunately.
I read somewhere that upping the speed and increasing the amounts of passes would eliminate the burning but while the burning did not occur, the laser still did not cut through.
As with any machining operation it will do the job with various settings, but only a limited range will give you the best cut…
If you cut the speed in half, you theoretically double the lasers power. It’s puts twice as much heat into the area since it’s moving half the speed.
I’d suggest your 3mm mdf setting and drop the speed by half as a start.
Everything being equal, you should only need to bump the parameters by 1/3 or the difference between the 3mm and 4mm mdf.
Are both of these mdf made from the same material?
Every piece of natural material vary, humidity or wood density… With mdf there is an unpredictable glue layer to deal with.
Just in case, is the focus distance correct? What happens when you use the same settings as for the 3mm plywood and do an extra pass with the same settings? Are you using air assist? (That usually also helps a lot)
Oh, maybe you use m to mean min? It is confusing if you use one unit symbol in place of another. SI unit symbols are typographically very significant, you don’t want to confuse M (mega) with m (meter or milli) with mm (millimeter) with min (minutes, not SI but standard noneless), s (seconds) with S (siemens) and so on.
Jack - I tried the setting you suggested, 150mm/m @100% Power with 4 passes as well as 90mm/m @100% with 4 passes and still there is no cut through.
Both the 3mm and 4mm are pine plywood, so technically no difference, but I am starting to suspect your glue theory may be correct, my wofe suggested that too.
Jaap - I have tried multiple focus points, using the focus pillar supplied, and been through all the speeds and alas, no luck there. I unfortunately do not have air-assist yet, maybe this years Cristmas present
Philippe - Yeah, took me a while to wrap my head around all the measurements, but I eventually got it. For me, using metric, mm/m = millimetres per minute, so that makes sense.
Again, thanks for all your input, I’ll carry on attempting things on the side, but I think these boards are destined to be cut into squares on the table saw and become coasters
Have you done a ramp test ?, as you are only using a 5.5w laser you will need all the help you can get to cut more than 3mm, a 5.5w is more suited to engraving than cutting.
Hi all
I just want to say a massive thanks to everyone.
I tried everything that everyone suggested and everything eventually fell into place.
I have upgraded the bed to a spike bed and pulled a MacGyver and hooked up my 50L air compressor for air assist. I have also worked on focusing the laser better and the cuts are so clean now.
240mm/m at 100% power with 5 passes, with air assist.
4 passes will do it, but a few little pieces get stuck, so the 5th pass just ensures all is done.
