Advice Please

[AnglePark]

I'm in the market for a laser engraver/cutter, and want honest working opinions. I'm a hobbyist, and don't want or need a production-level machine. I've been looking at the Redsail M300/500, but I'm concerned about quality/reliability and laser tube life.

I'm interested in a machine I can use to create architectural models from 1/8" plywood (similar to model railroad buildings, or the example of the Italian villa on the Epilog site). I need nice details on the model, as well as acceptable cutting ability. It doesn't have to be fast - just reliable, affordable, and do what little I need.

I may also occasionally want to create gifts (etched bottles or glasses), or cut/engrave thin acrylic sheets.

Price is a concern, as Epilog's 25 watt starts around $10K - a bit steep for something I primarily plan to use for a hobby. (It would take a long time for me to hit 10K with an imported machine - even replacing tubes at $300 each.)

Please - I'm interested in working experience here, and not necessarily input from sales folks or manufacturers.

Would I be better off buying a used/refurbished Epilog/ULS/etc., or a new imported unit?

Would a CNC router and the right bits (small bits) give me the same or similar results? (I'm guessing no.)

[RandyT2]

Originally Posted by AnglePark I'm in the market for a laser engraver/cutter, and want honest working opinions. I'm a hobbyist, and don't want or need a production-level machine. I've been looking at the Redsail M300/500, but I'm concerned about quality/reliability and laser tube life.

I have been using the Redsail M500 for over a week now and I still have those concerns. The tech department has been somewhat responsive, but I am experiencing accuracy issues that no-one has yet been able to help me solve. I'm no stranger to CNC machinery either, having assembled and tuned a 4'x8' CNC router table myself from an 800lb stack of parts..

The story is ongoing, so I'll save the details for when it ends. Until then, I would suggest waiting to move forward with your purchase from this manufacturer.

Randy

[ArturoV]

An older model of an Epilog with Some kind of warranty would be a great start. You wont waste time or money with other machines that will never reach the level of detail of an Epilogs or Universal.

[lamicron]

I have chinese laser , used it for architectural models (1:500 Intl. airport from my city) details were fine, cutting also. I dont find the difference with an Epilog in the cutting issue, maybe in engraving (I have not compared it yet) if you set the parameters as exact as your needs you 'll get it. This machines uses the same universal cnc system, if you look at the stepmotors, in one turn they have about 20.000 microsteps, that means you can set at least 0.001 tolerance ....

[RandyT2]

Originally Posted by lamicron I have chinese laser , used it for architectural models (1:500 Intl. airport from my city) details were fine, cutting also. I dont find the difference with an Epilog in the cutting issue, maybe in engraving (I have not compared it yet) if you set the parameters as exact as your needs you 'll get it. This machines uses the same universal cnc system, if you look at the stepmotors, in one turn they have about 20.000 microsteps, that means you can set at least 0.001 tolerance ....

Which "chinese laser" are you using? With the Redsail machine, I try to cut a 1" circle, with all parameters set as advised and get .020" geometric deviation...every time. In other words, not a true circle by a long shot.

There is more to the precision of a CNC machine than the number of steps in a stepper motor. That is like saying that one can put a Porsche engine in a '77 Buick and expect it to drive the same way. It doesn't work that way.

[lamicron]

Sorry but it works that way.. I mean the step motors, I will not try the porsce...My machine is a I mean exact by 0.001. In these parameters you change the numbers to get tghe exact displacement of the motor aqnd the numbers after the dotare 6 or 7 that means .000001. CNC step motors Work the same way in any machine chinese or german, you can take a look at the cnc plasma forum, you are using the same motors , diferent motherboards, but there are a lot of that stuff out there,,,,

[RandyT2]

Originally Posted by lamicron Sorry but it works that way..

No, it does not

The stepper motors are just that..motors. There are gears, belts, linkages, track, mounts, rollers and probably some things I can't think of at the moment between them and the laser lense. If just one of those things is poorly designed or assembled, you will have accuracy problems.

I can tell just by looking at photos of the internal construction of the "RABBIT" models compared to the Redsail models that there are major differences in the way these are constructed beyond the motors.

The steppers do not dictate the accuracy of the machine, only what is possible if all of the other elements are designed and assembled in such a way to support it.

[lamicron]

I do not think bearings and tracks or belts (in all machines are the same???)will make a difference, of course if there is a bad bearing you will not set the machine, but the real issue is between motors drivers and motion cards, there is where the orders come. As a cnc plasma machine builder ( and many other machines)I can tell you that. Maybe the machine you were working with was not set properly.

[RandyT2]

Originally Posted by lamicron I do not think bearings and tracks or belts (in all machines are the same???)will make a difference, of course if there is a bad bearing you will not set the machine, but the real issue is between motors drivers and motion cards, there is where the orders come. As a cnc plasma machine builder ( and many other machines)I can tell you that. Maybe the machine you were working with was not set properly.

I think we have a language barrier issue. This is what I have been saying from the first post. If you have a bad design or bad build, the stepper motors don't matter and don't dictate machine precision.

[lamicron]

Hi RandyT2, have you tryied this(see the photo) This parameter came out from Lasercut 5.0 software, I dont think your machine uses this software but you can find it in yours( as you have cnc experience) In this machine 1.3 is about 1mm of linear displacement. Draw a square with the square tool in the machine software, make it 100mm x100mm, then draw it with the laser on a MDF plate and measure it, I think it will not be the same size, then start to change the numbers in the axis that need it, then draw it again with the laser , make the lines very fine so you can make it really exact. I think in your machine ( as I have see in other brands )the reduction pulleys in the stepmotors are not the same for the two axis, for this reason the numbers will not be the same for both axis.
Let me know
Luis

[RandyT2]

Thanks for the suggestions. That is the software that was supplied. However, all of these settings have been adjusted ad nauseum without being able to take care of the problem.

When I first got the machine, all of the settings in the software were way off, with no documentation for my machine stating what they should be set at. So I experimented until I found a setting that worked, and did notice that the X and Y values were slightly different. When I asked, Redsail supplied me with the number, which matched one of the axes, but not the other. So I made them both the same number. At that point, it didn't really matter as the distortion of the circle didn't change much.

If the machine was just making nice ovals in the direction of an axis, I'd be pleased as punch. That's something that can be tweaked out. This looks more like a severe backlash problem in the Y-Axis, i.e. hardware issue.

Redsail is currently out on a Chinese holiday, but say they want to do a video conferece call when they return. I'm not sure why they think low-res, grainy video will help them solve the problem, and frankly, it seems pointless. Maybe they think I have a mouse stuck in the belt and want to help me find it....

[lamicron]

Always you asked about a problem the first answer is "send me video or photos" .
The numbers not always are the same for both axis, if you see the gear or pulley reduction could be different for this reason you will have to experiment different numbers. Have you draw the circle and after look at the measure tool? There you can change the measures, at this point if you continue geting the oval thet will confirm you have the wrong number on that axis.
Luis