High voltage wire flex


#1

@vagozs recently posted the email he received from FSL on the muse. One of their talking points was the high voltage wire flex going to the laser from the external power supply being a bad thing as the gantry moves. I know wire flex on some robotic applications need to be replaced frequently. Any comments from glowforge team?


#2

While I am not on the Glowforge team, I can tell you that there are special designs of wires suited for this type of use. From the care that the Glowforge team put into the design of the rest of the product, I assume they have thought about this.

To give you some idea of life - I have a 3D printer that uses normal 20 gauge wire to power its heated bed. This isn’t designed for flex, it is just the same wire you would get on a spool of 20 gauge wire. This wire carries 120 VAC and lasts about 2 years, with probably well over 3000 operating hours in that time. When that wire failed, I replaced it with a cheap version of a flex wire and it hasn’t shown any sign of wear. I have seen others of the same model printer I use that have been running closer to three years without any failure of that cable.

As long as the minimum bend radius is observed, the cable should last at least as long as the laser tube and if Glowforge has used a flex designed wire it will probably never fail due to fatigue.


#3

This is also (one of the many reasons) why engraving goes along the X axis, with Y traveling at a much slower rate.


#4

I suspect that the wire to the laser tube has been designed for the movement and it will have no issues.

I mean, hey, the laser head has fans, sensors, etc. and it experiences very fast movement. Surely power transmission to the head is not carried out by magic :slight_smile: and not to mention signal data back to the main logic board. There has to be some kind of wiring in there somewhere.

If these types of issues could not be resolved, we wouldnt have CNC equipment, inkjet printers, or even automobiles that experience millions of cycles of wire flex in a lifetime.


#5

I took this as " we failed at this engineering challenge so we don’t think anyone else can do it either". AKA sour grapes.


#6

Seattle is a boat city, half the engineers at GF probably own boats and know all about multi strand braided wire used in boats that is salt proof, flex proof, water proof, drown proof and maybe even bullet proof!


#7

They also said glass CO2 tubes can’t do variable power but that is why GF developed their own variable power supply.


#8

Do understand that this is high voltage and really is a design challenge, not just a matter of using multi strand wire.

I’ve seen it beat several times though.


#9

GF be ground breakers and earth shakers!


#10

For work I design tooling for industrial robots. So i’m mildly familiar with high flex cabling. The flex required in robots is significantly more challenging than anything the GF can dish out. This is because you have rotation along 2 axis. A robot can twist you cables up at the wrist while simultaneously bending it at the 5th and 4th axis.


The glowforge is just bending, and the radius is not that tight. IMO, its a design problem that is easily solved with off the shelf parts.

Just my 2c anyways :wink:


#11

and my 2c is I think you can see the gf solution in many of the images already available that should have been available when the Muse was being designed.


#12

This is marketing speak that assumes (hopes) that the Muse customer is ignorant of modern engineering and technology. Others here have explained it pretty well. It is a cable designed to flex, it doesn’t flex that much or that often. This is not an industrial machine operating 24/7. How often will it actually be moving the Y-axis? Just FSL marketing garbage. They are trying to peddle an inferior machine in many respects. They should just stick to their machine’s advantages. - Rich


#13

Indeed - this was designed in from the start.


Weekly Highlights for the Week Ending February 4, 2017
#14

User replaceable or send to glowforge for repair?