Lightobject.com Support Forum

What is the optimum speed?

I watched Tech Marco's video on the new design X-Y and when cutting it was fast, nice to watch... But for engraving I notice that he has set a speed of 1500mm/s
The problem is that the acceloration and deceloration took almost as wide and as long or longer than the engrave itself. So here is my observation,
if because of the speed, there is a significant Accel and Decel, what you end up with is 1500mm/s at the peak but overall the speed is more like 500mm/s and because of the distance that the accel and decel takes, and your workspace is 40% smaller

This is because if it takes 100mm to decel to 0 so the head can reverse direction, that is 100mm to the left of the engraving and 100mm to the right of the engraving so 200mm of the table can't be used at that speed.
That gives you an effective working area of 300mm or less, remember, if the head goes outside the table workable area you get an error

My question is How much longer is this same graphic to engrave at 400mm/s compared to 1500mm/s What is the optimum speed to engrave with this rig?

is it like this: Where after 500mm/s the time benifit is deminished and at 1500mm/s it actually takes longer and more power to engrave the same size object with the same pattern This is a 500mm wide table, the paper is, I assume 8.5 x 11 so just under 220mm wide, and the graphic is 1/3 that so say 72mm, the power to barely tarnish the paper is 95% at that speed... and it looks like it is taking just about as long as a 500mm/s pass once you factor in the increased Acc and Dec time...

This is what I see

Ha.. you got a very sharp eyes! Yes, you're right. At higher speed, it took longer distance to acceleration and deceleration
That's why I'm testing it with higher acceleration speed now. Amazing to see how fast it is traveling while I'm typing this message

Marco

It would be awsome if this rig could engrave the same pattern in 1/3 the time at 1500mm/s compared to 500mm/s which is currently considered very fast. You may need a different motor to handle that much torque though.

How are you guys getting good engraving results at these speeds? When I do an engraving of a complex image I have to set it to about 100mm/s in order to maintain detail. What am I missing?

what controller do you have?

DonL wrote:what controller do you have?

Me? AWC608 from LO.

seeigecannon wrote:

DonL wrote:what controller do you have?

Me? AWC608 from LO.

I am running the LO-X7 so I am not sure if there is a difference in the algorithms, Tech_Marco could answer that.

As I can tell, the algorithm for AWC608 and X7 and the new mini DSP are the same. Assuming if the algorithm is not the same, it won't be so much difference on speed; 100mm/s vs 1000mm/s. If it was 600mm/s vs 650mm/s it could be happen but not to such extreme difference, wow 500mm/s !!

There is much be something wrong on seeigecannon's machine. Either hardware or electronics.

The best speed with the best finished time that I could reach with the PRo530 was "1000mm/s" It was about 1min faster than 800mm/s and 1200mm/s. At 1200~1500mm/s, it lost time on acceleration and deceleration even though the actual speed could reach 1500mm/s on engraving area. But the actual time was taking more than 1000mm/s to finish


Marco

That is what I figure, High speeds like 1500mm/s are good for large jobs, big laser, where your graphic is maybe 3 feet wide, then the speed will make a big difference bacuse it will over the graphic longer than the accel/decell time but for small graphics it is takking longer to accelorate and decelorate that the time it is burning the graphic... This makes the job time longer tha it would at a slower speed.

So I would say that for a 300x200 table, 600mm/s is as fast as you can go, any faster is waisted.

500x300 table, 1000mm/s is the fastest, any faster is waisted

800x600 table and now the high speed is becomming useful, if you have a strong enough laser, at 1500mm/s it may be hard to engrave anything with a 60w laser running 90%, you would need a 120w or more...

These are just guesses and I could be off by a fair bit but you get the idea... Super fast is only good if you are engraving super big otherwise it is not so fast and can actually be slower to engrave small graphics.

Like running a Forula 1 Race car on a 1/4 mile oval track, by the time you get up to 100mph you need to slam on the brakes and slow down so you can reverse direction, You need a 10 mile track to really get the car to perform... and then it is beautiful!

You got it!

Marco