Laser Cut Plexiglass

glass. Anyone know if that is true?

intering, etc. The issue is that it has a corner on the edge that is causi ng some wear to a plastic object it is pushing on.

ruck me as odd like adding rollers instead of a flat surface.

but if the laser can be tilted, a 45 degree bevel would be easy. Even a 3

piece attached to the arm which then presses on the plastic bag. So it's o nly to the two outer pieces that need to be beveled.

guess because the bag is designed for hand operation.

Yes, as a matter of fact, a Fuji 3400 potato I believe. I bet you didn't k now Fuji made potatoes.

the arm in the center. The arrangement ends up being 70 mm wide, not coun ting the screws.

ing anything. The ones I've found only go up to about 40 mm. Gear shift k nobs or drawer pulls.

g looks like nail", in this case it wasn't a hammer it was a laser cutter

You are shooting the messenger. They seem to have in their heads that a la ser cutter is the ideal way of making plastic pieces. I don't know that I can do better making plastic pieces, but I am presently looking for somethi ng the right shape off the shelf. Knobs tend to be rather small, I guess t hey are designed for Trump's hands. Doorknobs are about the right size and shape, but I have no reason to believe they would hold up and may be hard to mount... unless they are not made to turn.

onsdag den 22. juli 2020 kl. 22.13.31 UTC+2 skrev Ricketty C:

xiglass. Anyone know if that is true?

plintering, etc. The issue is that it has a corner on the edge that is cau sing some wear to a plastic object it is pushing on.

struck me as odd like adding rollers instead of a flat surface.

l, but if the laser can be tilted, a 45 degree bevel would be easy. Even a 30 degree tilt would do a lot to relieve the corner.

e piece attached to the arm which then presses on the plastic bag. So it's only to the two outer pieces that need to be beveled.

I guess because the bag is designed for hand operation.

know Fuji made potatoes.

getting a bit closer, like low earth orbit might help ;)

is the arm in the center. The arrangement ends up being 70 mm wide, not co unting the screws.

aking anything. The ones I've found only go up to about 40 mm. Gear shift knobs or drawer pulls.

ing looks like nail", in this case it wasn't a hammer it was a laser cutter

laser cutter is the ideal way of making plastic pieces. I don't know that I can do better making plastic pieces, but I am presently looking for somet hing the right shape off the shelf. Knobs tend to be rather small, I guess they are designed for Trump's hands. Doorknobs are about the right size a nd shape, but I have no reason to believe they would hold up and may be har d to mount... unless they are not made to turn.

I didn't think it was you that designed it, so it wasn't directed at you, more a speculation on the likely design process

laser is popular with the "maker" crowd because it is simple to design "2d pieces" that stack and you can order parts cut online just as easy as PCBs or buy a laser cutter for a few $1000s

and using a laser is more like using a printer than a machineshop

Above a certain size they become pommels.

Have you considered the float from a float valve? possibly it'd not be durable enough. Or maybe some sort of wheel?

It seems a stange goal to design an inexpensive machine to be manufactured using the second most expensive manufacturing method.

the arm in the center. The arrangement ends up being 70 mm wide, not coun ting the screws.

ing anything. The ones I've found only go up to about 40 mm. Gear shift k nobs or drawer pulls.

rable

Rollers are what the lead guy is planning based on the most superficial exa mination of the wear on the bag. During a conference call another guy look ing at the same limited images I saw assured us that this was from friction rubbing and not from the edge of the plexi scraping the bag. As the bag i s compressed the it changes shape a pretty good amount so that the ends cur l upwards. I think this produces a scraping effect on the bag. Also, ther e is not much to hold the bag in place.

I would want to examine the problem further before trying to effect a fix. In any regard, the bag is going to suffer fatigue in rather short order. It may last weeks, but it won't be months of use. I don't think they have accounted for this yet. This is something you would want to consult someon e in either the manufacturing field or the user field to know what is accep table for wear and maintenance.

Heck, I've tried to explain the problems of an internal battery since they can't be left for long periods without charging (SLA). I don't really thin k this has an impact on any decisions. I expect these units to be used one of two ways. Either they are bought in advance and stored for who knows h ow long before being used, or they will be built in a panic when another pa ndemic hits. To be honest, I think the issue is moot at this point because enough time has gone by that whoever needs ventilators can now get them. The problem was everyone wanting them at the same time. Even if there is a nother spike in the fall, will there be another crunch like there was in th e spring? Even with all this time to prepare?

I'm not even sure this will be ready by the fall.

Are you suggesting we use knives and whittle ventilators? Should we use al l through hole electronics so they can be assembled by hand? Or maybe like one guy here who was trying to design electronics using parts they could g et from scrap devices in the third world? The 8051 is back!

There are a lot of inconsistencies. At one point in the previous group I w as suggesting something other than an Arduino like one of the many tiny MCU boards some of which have second sources. It was pointed out to me that i nitially in the pandemic shipping was a problem. They claimed the Arduino was available from lots of local vendors so that was the smart choice. Ano ther issue was about enough of a selected part being available from stock t o make 10,000 units. I don't think the local shops would have 10,000 Ardui nos.

This is why engineering has formal planning and management techniques. The actual design work is usually the easy part unless maybe you are designing an SR-71. We aren't designing an SR-71.

Yeah, in many ways this is a maker group.

Quick aside if you don't mind, know where I can get something like this made? (not that large)

If you want a store a lead acid battery for a long time store it dry.

Only if there's a perceived profit in it.

I'm suggesting that NC methods are one step up from that. injection moulding, and pressing are cheaper.

PONOKO ask them

The laser will cut both kinds of plexi if you have enough laser power for a given thickness and enough assist gas pressure to clear the cut, Up to sa y 3/8ths inch in Plexi if I remember right for an under 100 Watt Co2 Laser. . There is a physical depth limit for a one pass cut in many materials, at which no matter how much energy you throw at it, you'll hit a limit.

It will cut the plexi at an angle, but it will trepan the edges due to inhe rent issues with the laser optics. In other words the edge will have some slightly different angle then what you set the optics head for, and the edg e may not be perfectly flat. Wiki on trepanning is quite good.

You can go to the Synrad web site and download their materials calculation software.

I'm an avid Synrad fan because the low cost Asian hobby grade tubes are onl y good for 400 hours or less. They have never got the catalyst right for lo ng gas lifetime, and I doubt they will ever bother to invest in that resear ch.

Steve

Steve

a given thickness and enough assist gas pressure to clear the cut, Up to say 3/8ths inch in Plexi if I remember right for an under 100 Watt Co2 Lase r. . There is a physical depth limit for a one pass cut in many materials, at which no matter how much energy you throw at it, you'll hit a limit.

herent issues with the laser optics. In other words the edge will have som e slightly different angle then what you set the optics head for, and the e dge may not be perfectly flat. Wiki on trepanning is quite good.

n software.

nly good for 400 hours or less. They have never got the catalyst right for long gas lifetime, and I doubt they will ever bother to invest in that rese arch.

Not sure what you mean about trepanning the edges. When I look it up the d efinition is to make a larger hole by cutting a ring around the edge of the hole rather than boring the entire area.

When you talk about cutting the plexi at an angle you mean like tilting the blade on a circular saw, right?