Large Scale Central

Laser cutter questions

Modeling Technical Modeling
#1

I’m interested in getting a laser cutter, and am looking at the Chinese units on Ebay / Amazon. My thanks to Dave Bodnar for his great seminar at ECLSTS last year, and article about it on trainelectronics.com.

I need to be able to cut up to 22-24" long parts, so the 500x700mm units are attractive (see below). I’m not going to be able to get an Epilog or Full Spectrum, because I need to stay near $2k.

I’ve heard bad things about the units, such as the laser tube going not lasting at all, the software being poor, bad mother boards, etc. But, I’ve heard good things as well. So, if you have some insights, I’d be grateful. Here goes with the questions.

Vendors / manufacturers: any that need to be really avoided?

Reviews: With all these units being sold, why the absence of Ebay reviews?

Support: I don’t see any email addresses, support web sites or forums specific to the manufacturers of these (except one: hflaser.com). Anyone had successful support contact, and if so, with whom? Anyone found a helpful forum or two?

Control: any opinions on what software to look for / avoid? I’ll be using DXF files. Some cite AutoCad output or DXF, and that’s a gotta-have for me.

Power: I need to cut up to 1/4" plywood and acrylic. Is 50W good enough?

Functionality: Some units mention only engraving, some only cutting, some both (which I’d like). Is there actually a diff? Do I need to make sure I get a unit that says it will do both?

Is one able to etch deeply enough into acrylic material to emulate a joint between boards (after painting)? Is that sort of a matter on high high the power setting is?

Motorized up / down (vs manual): What’s the purpose? Is that a sort of auto-adjust for changing material thicknesses?

Sheet size: When they cite a working size (say, 500x300mm), is that the size of material you can shove in, or what the laser can actually cut to?

Installation: are these the kind of thing you can stand on end and maneuver with a furniture dolly, with a couple people?

Here’s the reason I’d like to get a 700x500mm unit. The main purpose of this would be for large mining structures (served by the V&T) and other buildings on the layout. I did an example pattern set using 300x500 and then 500x700.

I learned from this exercise that, for this particular structure at least,

  • The larger unit would save gobs of time (less than half the effort) in material pre-cutting and machine loading
  • Would require far fewer material splices in the structures
  • Slight savings on material, due to joint avoidance inefficiencies w/ the smaller unit

Sorry for the long-windedness, and many thanks for any pointers & opinions.

Best,
===>Cliffy

#2

I hear your fears and havent yet sprun for a laser cutter…Might still happen but not yet

#3

You might be interested in contacting Bill Brillinger. He’s a Ho scale modeler that also does a side business with his laser cutter. He posts over at the MRH forum, his website has an email contact. He might be able to help you out.

http://pdc.ca/rr/

#4

Craig Townsend said:

You might be interested in contacting Bill Brillinger. He’s a Ho scale modeler that also does a side business with his laser cutter. He posts over at the MRH forum, his website has an email contact. He might be able to help you out.

http://pdc.ca/rr/

Along that same vein, I would contact Phil Dippel (from Phil’s Narrow Gauge). It seems like every time I talked with him he had a new laser story. Great guy and very talented…

#5

Cliff,

one thing you cannot do is rely on the outside edges of the sheet in your drawing, there always needs to be some off set from each edge, in the range of 1/4-3/8 inch per side (depends on the laser). internal shared edges are fine, but you want to make sure there is only one line in your drawing, otherwise the laser will make multiple passes over the area. I have done a far amount of laser cutting in large scale, but do not own a laser. not worth the aggravation. I work with someone who uses theirs full time making kits and knows all the ins and outs, so I get great results on the first try. cutting 1/4 inch thick material will be a challenge due to the angle of the laser beam of about 5 deg. per cut leaving tapered edges. there are folks that do it but are few and far in between. my guy will only do up to 1/8 thick in wood. have not done much in acrylic, but know you need a good ventilation system as the smell is atrocious.

Al P.

#6

Cliff
I have seen several of these chinese lasers on ebay, i have heard only negative on them
Now the commercial machines i have seen at the large trade shows that we exhibited in, are much
different quality with support and the basics that you have mentioned, but not at your price you mentioned.
I am going to say what you already know, you do get what you pay for.
I know the length of life of the tubes, are hugely different, in life and in price. I know when I change a tube in one of my Epilogs I drop 1800 bucks. but we run 3-6 hours per day, and get 2-3 years per tube.
I have heard, (you know what heard means} that the cheaper Chinese tubes last weeks in the usage we do.
The commercial chinese units will use the better tubes. still less costly than epilogs.
The commercial machines run about half of epilogs price, but have the features you are looking for.

Now for a different page of this book.
I will always own a laser, the most fun tool / Toy I will ever own. But we buy them for business purpose.
BUT, you have the ability to do what takes the longest to produce any project. Designing and drawing the parts up is the most costly , (if had to pay for) you do 3D cad as good or better than most people.
Lay everything out and get another company with lasers to cut them out, you can get alot of projects cut long before you can own a larger unit.
Maybe try a smaller import unit for all the small stuff.
Compare your 3D printer qualities, compared to what you get from Shapeways.
you hear what I am saying.
Dennis

#7

Al Pomeroy said:

Cliff,

one thing you cannot do is rely on the outside edges of the sheet in your drawing, there always needs to be some off set from each edge, in the range of 1/4-3/8 inch per side (depends on the laser). internal shared edges are fine, but you want to make sure there is only one line in your drawing, otherwise the laser will make multiple passes over the area. I have done a far amount of laser cutting in large scale, but do not own a laser. not worth the aggravation. I work with someone who uses theirs full time making kits and knows all the ins and outs, so I get great results on the first try. cutting 1/4 inch thick material will be a challenge due to the angle of the laser beam of about 5 deg. per cut leaving tapered edges. there are folks that do it but are few and far in between. my guy will only do up to 1/8 thick in wood. have not done much in acrylic, but know you need a good ventilation system as the smell is atrocious.

Al P.

The angled cut in the cut line is the result of needing to adjust the laser to the center of the lense, the laser being just a little off the center of the lense will result in an angled line in the cut, the mirror on the end of the arm needs to be adjusted, I cut 1/4" wood and acrylic, I cut 1/2" diameter circles to make sure they rotate a full circle in the hole, if it rotates a full circle, it is cutting straight.

Dennis

#8

Cliff - It is good to see that you are thinking about taking the plunge!

As you know I started with a $400 40 watt eBay laser. It was a great & inexpensive way to get started - in April I decided to go for a larger unit and settled on a 50 watt eBay laser cutter.

I was quite apprehensive about buying one as I, too, had heard stories about poor quality, failures and nonexistent support. After viewing a number of Russ Sadler’s excellent videos on YouTube I had the confidence in being able to do adjustments and repairs (should I need to) and I placed my order. (Russ’s videos are here: https://www.youtube.com/user/SarbarMultimedia/videos HIGHLY RECOMMENDED for anyone with a laser cutter)

This is a much bigger and heavier unit - shipping weight was about 220 pounds! The good news is that it worked well out of the box. A few months after purchase the power supply for the laser failed. I emailed the vendor through eBay and, to my surprise, he sent a replacement without any proof of failure on my part or the return on the dead power supply - excellent!

That said, there is no guarantee that a similar unit, even from the same vendor, will perform equally -

Here is a link to the one I purchased - it does NOT have a powered table lift - that would be nice but not mandatory for me.

http://www.ebay.com/itm/281882801833?euid=f3125d1982fc48babd14c2668fd13ff5&bu=43184653931&cp=1&sojTags=bu=bu

Let me know if you have any questions - if you prefer feel free to give me a call (412)343-0706

dave

#9

Craig and Bruce, thanks for those referrals, I’ll check into them.

Al, thanks for all those tips. So it sounds like a line running right off the sheet would confuse the laser? Hence keeping all the linework internal to the sheet. does that sound right?

I’ll put in a vent line, and it’ll have to be good, because the spot I have is in the basement (under the dining room). Atrocious smells not allowed… at least, nothing lingering or major. But I have exposed joists over the area, so running duct shouldn’t be a problem. Hope the machine’s duct port will be adequate, on I don’t want to have to install big vent hood over the whole thing.

Dennis, thanks for all your comments, including those related to kerf. I completely agree with the quality concerns over the Chinese units. But I need the larger work space, and the unit (installed) needs to fit within a $2,500 max budget, or there will be serious marital consequences. EEK!I also appreciate your advice to get the cutting done by others. I haven’t found anyone local to take it on though, after several searches. My mining structures alone will eventually involve around 16 4x8 sheets of acrylic, so that would be many thousands in cutting fees I’d expect (over several years). So, that’s why I’m considering the lower-quality cutter.

Dave, thanks for those comments and links! I’ll go investigate and reply after.

All, here’s the front-runner I have in mind at the moment.

http://www.ebay.com/itm/291411058723

I emailed the vendor with several of the questions I initially posted here, and will report back on their replies when I get them.

Best regards,
Cliff

#10

David Bodnar said:

Cliff - It is good to see that you are thinking about taking the plunge!

As you know I started with a $400 40 watt eBay laser. It was a great & inexpensive way to get started - in April I decided to go for a larger unit and settled on a 50 watt eBay laser cutter.

I was quite apprehensive about buying one as I, too, had heard stories about poor quality, failures and nonexistent support. After viewing a number of Russ Sadler’s excellent videos on YouTube I had the confidence in being able to do adjustments and repairs (should I need to) and I placed my order. (Russ’s videos are here: https://www.youtube.com/user/SarbarMultimedia/videos HIGHLY RECOMMENDED for anyone with a laser cutter)

This is a much bigger and heavier unit - shipping weight was about 220 pounds! The good news is that it worked well out of the box. A few months after purchase the power supply for the laser failed. I emailed the vendor through eBay and, to my surprise, he sent a replacement without any proof of failure on my part or the return on the dead power supply - excellent!

That said, there is no guarantee that a similar unit, even from the same vendor, will perform equally -

Here is a link to the one I purchased - it does NOT have a powered table lift - that would be nice but not mandatory for me.

http://www.ebay.com/itm/281882801833?euid=f3125d1982fc48babd14c2668fd13ff5&bu=43184653931&cp=1&sojTags=bu=bu

Let me know if you have any questions - if you prefer feel free to give me a call (412)343-0706

dave

Dave, thanks for those links. I’ve begun working through Russ’s videos, and it’s so much to absorb… wow. I started with his Lightblade vid, but then looked up the price; so I’m now going through his work with the 40w unit, and now I think I’m in the territory of the machine you just bought.

RDWorks Learning Lab 75 What have I learned from 1 year of owning a Chinese Laser Engraver

https://www.youtube.com/watch?v=GNV0JUJXdvk

Now, Russ describes a nominally 50w machine, yet it had a 40w tube. He explains that the tube soon needed upgrading to a 60w, and a different power supply with it. What are your thoughts on this?

Thanks for the link to the unit you bought. For me, the link opens up on a unit that hasn’t shipped yet, is this the same thing? And you you think they’ve addressed the tube issues?

http://www.ebay.com/itm/281882801833

Thanks again!

Cliff

[edit] I’ve just found Russ’s initial video on the laser topic:

https://www.youtube.com/watch?v=YvrMeUUzaBo

[edit 2] Hmm, noise levels might be a problem with the location I have in min…

[edit 3] Russ’s version has that motorized (vs. manual) up-down function. I didn’t see that feature offered in the current ebay units, and I still don’t understand why that would be beneficial (Russ said it was, but not why).

#11

Cliff Jennings said:

I’ll put in a vent line, and it’ll have to be good, because the spot I have is in the basement (under the dining room). Atrocious smells not allowed… at least, nothing lingering or major. But I have exposed joists over the area, so running duct shouldn’t be a problem. Hope the machine’s duct port will be adequate, on I don’t want to have to install big vent hood over the whole thing.

Best regards,
Cliff

Even after the cut acrylic comes out of the laser, it stinks for days. My wife hates the smell when I bring parts home. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-yell.gif)

#12

Cliff - you really need to view Russ’ videos in order from the beginning skipping those that are not of interest.

He has done a really amazing amount of work on these units.

As to the tubes his theory (and it is likely valid) is that the Chinese ship seconds or over-rated tubes - I have not had any trouble cutting 1/4" acrylic & MDF with mine - I do have a backup tube ready to put in should I need it.

dave

#13

Todd, you’re confirming my fears… I might have to make a garage home for the thing, which I’d rather not. We’ll see.

Dave, I just finished his tutorial #6, my head is blown… Very thorough and instructive. Do you have the new 50w unit already? And what power level are you running it at?

#14

Cliff - I have the same style 50 watt unit that is in Russ’ initial videos - based on its cutting ability and some tests I have done I would say that it is putting out close to 40 watts. That is plenty for my purposes right now.

One thing to keep in mind, no matter what unit you get. If it does not come with an analog millamp meter I strongly suggest you install one - my first one had it and the new one did not so I added one - You need it because you need to make sure that you never exceed the power capability of the laser tube by feeding it more amperage than it is designed for - that is one way to shorten the lift of a tube. The analog meter makes it easy to monitor power from the power supply to the tube.

As to smell, I added a 2nd fan to my unit and my wife still comments on smells when I do acrylic.

dave

#15

Cliff - one other item that may be of value to you is an index to the first 93 videos that Russ has posted - it is here:

https://rdworkslab.com/viewtopic.php?f=6&t=1174&sid=4f193a1af07e12be2e5c6e6bc7abc299

It makes it much easier to navigate his offerings.

dave

#16

Excellent Dave, thanks.

I saw a video where the user installed an ammeter like you say, in addition to the one Russ spoke of. Question: if the tube is 10W less than the published wattage (as Russ claims, and it sounds like you’re verifying), how do you know what mA to not exceed?

I’m preparing my next round of questions to the vendor, and will ask about the ammeter. They answered my first batch quickly, I’ll post later on that.

Cliff

#17

Here’s my questions (as of Sunday) and their responses (as of this morning). Things in brackets are my comments.

Dear sunshinesmileservice, [that kills me… I can’t believe I’m contemplating a vendor with that name… (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)]

Hi, I’m interested in this product, but have questions.

Support: Can you describe how I would get technical support? And what is covered in the 3 year warranty?

It has 3 years warranty, if it has problem, you contact me for help. [The following is boilerplate, repeated in an earlier email:] Don’t worry; you are strictly protected by PayPal. And the order process is exactly same as eBay. (the three year warranty is NOT only a ebay warranty, we provide it to all my customers who making payment directly via PayPal as well, they are still under PayPal protection, It means that PayPal will refund the money to the buyer if we are unable to provide with warranty. I have to stress here: our item is excellent quality, at least we have NOT yet get any problem from this item)

Functionality: This will perform both engraving, and cutting, correct? What thickness of acrylic or wood will it cut?

Yes it perform both engraving, and cutting, 0-4mm thickness of acrylic and 0-6mm wood will it cut.

Motorized up / down (vs manual): What’s the purpose? And if it is important, how can I obtain it?

Motorized up / down, the machine has two switches can control it up and down to adjust the distance between the laser head and the mateial.

Sheet size: You mention 700x500mm. Is this the max size of material? Or can the laser actually cut to this?

700x500mm is the working table size, the max size of material.

Can I also obtain the rotary attachment?

It doesn’t come with rotary attachment, if you want, it is 180USD per unit.

Shipping:

My offer includes the shipping. And tracking # would still be updated to you asap. Once we receive your payment, we will send out the package from USA warehouse on the same day or within one business day. Estimated Delivery is 5-6 business days. Also if you need the liftgate service, it is 75USD.

What is the operational life of the laser tube?

It is about 3000-3500 hours [… ]

Do you provide replacement tubes? And how much do they cost?

[…] and we also replacement tubes, it is about 250USD per unit.

#18

Amps, or miliampres would be watts divided by volts. How many volts goes to the tube? 40 (watts) divided by how many volts would tell you what current to shoot for.

#19

Here’s the first video I watched on the subject, prior to Dave’s pointing out the series by Russ. Seemed to have some good tips.

He referred to an initial video he made, and this is probably it.

#20

Cliff Jennings said:

Excellent Dave, thanks.

I saw a video where the user installed an ammeter like you say, in addition to the one Russ spoke of. Question: if the tube is 10W less than the published wattage (as Russ claims, and it sounds like you’re verifying), how do you know what mA to not exceed?

I’m preparing my next round of questions to the vendor, and will ask about the ammeter. They answered my first batch quickly, I’ll post later on that.

Cliff

Cliff - my power supply puts out 2000 volts and I am treating my laser tube as a 40 watt unit so I don’t exceed 20 ma on the analog meter — 20ma at 2000 volts is 40 watts… simple!

You can pick up the metes on eBay for $10 or less - I got a 50 ma meter

dave