RDWorks Learning Lab 58 3D carving At last!!
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- čas přidán 10. 04. 2016
- If you own a Chinese laser cutter this little series of videos about me learning how to use the free software provided, may solve the problem of trying to learn from a virtually unreadable manual.
I am nothing to do with RD Works, I am not an instructor and I am no expert. This series will document the essential bits of many hours of trial and error - Věda a technologie
I read somewhere that the frequency setting in the program is only applicable if you have an RF laser. I will be interested to see what you hear back from your sources.
Great job as always and thanks for sharing your experience.
Hello Russ,
I have a quick question. I Just purchased a china laser and I'm having a hard time setting the origin. I move the x and y axis to where I want it to be and click the origin button on the controller. However, When I start the project the head moves to the lower right hand corner as if the origin is set to the lower right. I've watched all the videos but none show how to exactly set the origin. Any help would be greatly appreciated. Keep up the good work your videos are a excellent learning source and I commend you on the great work.
Thanks,
Chris
I wonder if the acrylic would take to a heat gun treatment. Loving the videos. Thanks
I think you will get less grainy results if you lower your Interval setting to something like 0.05mm. You will probably have to lower your power to compensate for the overlap, or increase speed.
Hi did you try to play with the intervall? Its usually set up at 0,1 lines per mm so set up to 0,05 and you will have double as many details.
Thanks so much for this video. Really straightened out my issues with relief engraving.
Hi Marti
Take a look at
czcams.com/video/0E6VfQD9n2o/video.html
and
czcams.com/video/j5cIFxGu_1g/video.html
Best wishes
Russ
This is great! Thank you once again..
I keep watching them as they come out Russ! Already waiting in anticipation for the next one. You've created some groupies I think! Plus... We ordered our 50w Chinese Laser today!! YES! I was careful to choose one off of eBay that looked like yours, with the goldish heads and mirrors. It "claims" to be an 'upgraded' model compared to the majority of the other 'black head and mirror' setups on there. Thank you for helping with the learning curves once again. ~ Chris Miller
+Christopher Miller
Hi Chris
Thanks for your appreciation. I hope you will be pleased with your new techno toy and can enjoy playing with it rather than fixing it (as I had to). But, although fate dealt me a less-than-perfect machine, it has forced me to learn a lot about the technology that I would otherwise not explored and also there would be far fewer videos. Make sure you order your cheap 30mA ammeter from China, it will be your best friend ever!
Best regards
Russ
When you lower the number of the interval(mm) from 0.1 to a lower number in the scan settings page, it will decrease the amount of space between the scan lines. It will take a lot longer, but will give you even more finer details as far as i remember. Try that on one of your engravings and see what happens, It should make it look nicer / refined.
just a thought... do you think you are loosing definition on wood because the sample is so small?
I would be tempted to (for example) take just the wing off the bird and make it bigger in size, and try that on the wood...
Hey Russ. Just curious to know if your using cast or extruded acrylic for that last etch? Extruded is much better for etching as it gives a more smoother finish. Also you good heat the etched area up with a miniature blow torch to smooth it out further. Excellent research here
+Mohammed Ali
Hi Mohammed
As thickness increases extruded acrylic tends to be a rare breed and most of what I use is offcuts from a large supplier (that I get almost for free) and tends to be cast acrylic....I can't be too choosy with that deal. Flame polishing as a second operation is not something I had considered......... but it's an excellent idea. I may try running the program again at a lower power/faster and defocused by maybe 10mm to see If I can deliver a controlled polishing effect.
Thanks again
Best regards
Russ
I not sure if you're aware but I have to tell you that before engraving relief engravings you must dither the image first, only then you will have good results even with your "specially prepared images" which are in fact grayscale from 3D relief made in ZBrush or ArtCamPro, Im 3D modeler myself thats how I know it, I also have 2 laser engravers which I m using for more than 7 yrs now pro. Also you must set one direction laser beam so it will not burn too much. You have dithering tool in RDWorks as well, under bitmap handle menu. Cheers. I forgot to tell you, you need to make laser beams from line to line closer for this setup, about 0.08.
Hi Toni
Sincere thanks for your feedback. As I am sure you know I'm still learning about this machine and technology and my venture into 3D carving has thrown up so many questions about the machine that I wish to understand and that's before I get into the finer points of 3D creations. I am not a graphic artist, just a simple mechanical engineer without the software tools you mentioned. As a professional passing on the benefit of your experience, I cannot thank you enough because trying to find information about the details of this subject has been impossible.
I am on holiday at present so am unable to play with my machine.
There is one thing about your dithering suggestion that puzzles me immensely. My understanding of dithering is that it's a way of converting a grayscale image into a binary black and white format where the density of the fixed size black dots recreates the effect of a grayscale image but with binary information. You set the the laser to a fixed power, scan speed and scan pitch, then as the scan happens, the laser power is either ON as it encounters black dots and OFF in white areas.
On the other hand, as I have found out by experimentation, when you set the max power and min power to different values and leave the image as an original multi-tonal image, RDWorks breaks that image down into scan line data that has continuously varying power information across the scan, where that varying power is one of 256 levels between the max and min power levels set. This causes a continuously varying depth of "burn" and scan line by scan line gradually builds a 3D rendition.
As I have been experimenting with dithered images on thick card I have noticed a sort of shallow 3D effect as the burnt dots overlapped in the very dense areas. This is an interesting effect but not 3D carving.
The uni-directional scanning and line spacing are items on my experimentation list when I understand more about how the laser beam is controlled in scan mode as opposed to cut mode.
I am now more fascinated by your introduction of dithering to this process. I cannot see how binary dithering and continuously varying grayscale scanning are complementary. Can you please explain further
Sincere thanks for your input
Best regards
Russ
Have you tried to develop settings to remove char on a second pass? I seem to recall someone saying to run it faster and with lower speed but can't find where I saw that.
Hi Marti
I fell into your trap of trying to remove too much material at once and getting a charred finish.. Once there, it is almost impossible to clean it up. My guess is that you are using a 2" lens. Not the best idea because it is too "sharp" I found that either a 2.5" or a 4" lens was better for 3D work as both are much "softer" and less prone to producing charring. That is the real trick. Use a longer focal length lens and do some tests on the wood you are using,, setting the speed to 300 to 400mm/s. Make some small test engraving squares and test each at different power. You are looking for the combination of speed and power that removes the most amount of material without charring or significant scorching. It may mean you have to do more passes (6 or 8 maybe?but the results will be good The Y increment setting is also important to add that into your tests as well. If your scan lines are too close you will get over burning so you may finish up wit 0.2 to 0.25mm increment.
Best wishes
Russ
This is awesome! Now that laser engraving has progressed to this level, now I am sure that one can use lasers to mill also....even to do SURFACE FINISHING...which is awesome, because if one can mill using a laser, there are no 'work contact' related forces to deal with which lower the cost and simplify the design of cncs in countless ways!
Could you (if you are not looking at this already), look at trying to develop methodology for milling material away and then (using the same technology ? for carving shown here) demonstrate the ability to do some (even crude "finishes" would be AWESOME!) finish passes on steel or aluminum???!!! Wow! That would revolutionize many aspects of machining and manufacturing!!!!????
Hi
Sadly I'm afraid your dream will have to remain "dreamish" at present. I have been involved in engineering all my life and particularly production engineering where I am always chasing your dream. I owned my own metal cutting laser business with two 3kw machines. All the old techniques of welding, stress relieving, rough machining, finish machining etc etc all disappeared from my book when laser machines came along. There are so many things that can be converted into 2pieces and accurately laser cut and assembled to bypass many of the traditional manufacturing costs. Although these little machines are fantastic value for money they are not anywhere near your fantasy yet. Firstly these do not have the power to cut metal. HOWEVER there are some new high power fibre optic laser engravers that can do some amazing tricks with surface finishes. I can't put my hands on the link at present but I will look later
Best regards and thanks for you comment
Russ
The frequency that you mentioned is the frequency of the PWM signal that goes to the laser power supply. The supply has what is called an RC filter inside of it to turn the digital PWM signal into an analog signal. The cheap capacitor inside of the RC (Resistor/Capacitor) circuit might explain some of the non-linearity that you have seen in a previous video. You might be able to do your linearity test at 5k, 20k, and 50kHz to see what gives the most linear response.
Also, I have done some quick translation work on RDWorks to go from Chingrish to English. Let me know if you (or anybody else) wants a copy of it.
My laser lens is set in a drawer that I just pull and insert the other lens drawer in.
another great video. now that you have a true 60W tube which is I deal for engraving. could you post what you are now able to cut like material, thickness. power or ma setting and number of pssses etc I would like to order a machine and would like to see some real world figures of what a 60 w can do. a lot of the makers say 90w but the engraving detail will be far less is my understanding
+3K Carbon - G10 - FR4 - Supplies & CNC Routing - 3D CAD Design & 3D Printing - Online Shop
Hi
In the past I have always used %power and speed when I have talked about machine settings. But of course that's pretty meaningless because now I have the 60 watt tube the previous % power settings are meaningless. I plan to record my future data in a more universal way ie watts and speed. Now this is a problem for many people because they do not have power meters and do not know what power they are using. I do not yet have much cutting data from my new tube but you can go to
www.thunderlaser.com/download/down/parameters%20for%20different%20materials-60watt%20SP.pdf
and get a good representative list of parameters. I suspect these parameters are for a 2" focal length lens and will understat what you will be able to achieve with a 1.5" lens.
Double cutting? Yes I have done it and it sort of works but is very inefficient and its success is very material dependant. With acrylic it works reasonably well but you may get a bit of a rough finish to the second cut. Acrylic evaporates whereas most other materials BURN. The smoke in the cut itself is a fantastic absorber of the infra-red radiation so a CLOSED cut just harbours the smoke and absorbs your power. Double and triple cutting does nothing more than make a bigger mess of your cut. You ideally want tp slow down to a point where the material cuts right through and the air assist will blow the smoke out the bottom of you cut
Engraving does not require huge power. If you buy a 50 watt machine the chances are you will get a 40 watt tube. That 40 watts will typically span 10% to 60 % ie the machine programe will typically have control 40/(60-10)= 0.8 watts per 1% power. If you then upgrade it to decent 90 watt tube, the chances are you will get 100 watts at about 65%. Now the program has control of 100/(65-10)=1.8 watts per 1%. That finer control of the power for a lower power tube is what's being discussed when they talk about better detail.
The other factor that may influence your decision is the ratio of cutting to engraving you will do and if it's for a business . Higher power can mean higher productivity (higher cutting speeds ) in most instances. I have used 30 watts at the nozzle to cut 15mm acrylic but at 1mm/sec and also 12mm plywood with a 1.5" focal length lens. 60 watts gives lots of flexibility but beware of buying a 60 watt ebay machine. Ask lots of questions of the vendor because the chances are that their 60 watt machines will be 50 watt machines with 60 watt power supply.
Good luck
Russ
Is there any way to generate a fill pattern with dots reliability?
RDWORKS has a dot mode (scan, cut, dot), but it can only follow lines and it causes the machine to loose stepper motor synchronization. So everything gets distorted. My machine is able to cut and scan without loosing stepper motor lock, even at very high speed. At even very low speeds, the dot mode causes stepper loss. I noticed in scan and cut modes, the head accelerates and decelerates without discontinuities. In dot more, it appears to jump abruptly, thus causing stepper lock loss.
I want to engrave with dots since it should generate the best visual effect for lighted signs. Same principle as back light wave-guides for LCD display.
Hi John
There are two possibilities for you.
Right at the bottom of the EDIT menu there is a feature called LGP design. I have no knowledge of this but it is specifically for doing what you want.
I have found that back engraving quite deeply into acrylic leaves a matt crusty finish in the letters/ lines which is great for picking up edge lighting, not necessarily good for photo's.
There is a feature in RDWorks that you will be able to employ. Here's a simple example to test it with.
Draw 2 concentric circles in RDWorks.
Put a marquee round the whole.
Select Handle and choose Graphic Hatch. A bmp resolution window appears. Set 100 say. and press OK. The outer area is now a bitmapped area and a BMP layer appears in the parameters list.
DONT put a marquee round the whole, that will select BOTH layers. Just click in the grey bitmap area and handles will appear on the bit map layer only.
Select Handle menu and click on Bitmap Handle
NOW its all down to your taste.
Tick output resolution. Tick Dither. Tick Dot Graphic and click Aply to view to see what you will get. Change the resolution to 50 and click apply to view
When you get the look you want then click Apply to source and and OK
Check with Preview to see an idea of the cut order and what you will get.
Hope this helps
Best regards
Russ
I found out how to make Dot not loose lock. Speed x Dot time = Dot Length
Motion becomes smooth and sync is maintained.
Hello again Russ
The machine we have has a setting in the controls panel named user...the option that I discovered was the scan mode option...it's set from the factory on normal state...if you select special scan mode it's allows for proportional scanning....it's free tried it and it works great.
+Scott Thorne
Hi Scott
Very interested. I'm up to my eyeballs with urgent paid work for the next few days with little time to play. What's the difference that you noticed.?When I get time I'll play as well to see what's possible. Thanks for the info
Sincere regards
Russ
+SarbarMultimedia Russ
The overall depth of the engrave changed...the light grays were more pronounced as well as the darker shades of gray...I actually read about the setting in the operation manual for the software.
Hi, I need to know if this machine engrave in metals or not, I did buy the same machine but the 100w?? and which metals?
+Abdalla Safwat
Hi Abdalla
Sadly you will need lots more power to do any sort of damage to a metal surface( 200watts +...). You cannot engrave metals but you can mark them by a chemical reaction with the surface as you will see in czcams.com/video/b_06laAjMPc/video.html. You can etch aluminium provided it has been anodized. It's dangerous to fire the laser beam at most metals (see the 3 part video on reflectance czcams.com/video/kJe16YQlIM0/video.html ) so be careful.
Sorry it's not good news
Best regards
Russ
Thank you so much
I thought the curved side should be down towards the material?
Hi
Most Chinese machines appear to be shipped with lens installed curved side down. The lens will work ok that way round but tests show that you get a slightly shorter focal length when you set flat side to work and also a better (smaller) spot size.
Best regards
Russ
thank you for that!
Russ, RDWorks Learning Lab 58 3D carving. Your better engraving woods here would include Balsa, Poplar and African Mahogany. Not Lauan (Philippine Mahogany). All considered Hard woods but are quite soft. For CNC fine detail routing, I believe, they will include a non-fibrous wood made almost totally of a specialized adhesive and wood sawdust. In addition to the stepper motor drag markings are the irregularities in the wood caused by of the open grain patterns on the faster growth trees. Walnut, Cheery, Maple afford the impressive grain patterns which command greater cost to the customer. Not intended to be a masters thesis on wood only some general information. For extra fine carving/etching woods from Africa stunning and exotic.
Hi Ron
Great information for which I am grateful. My aim is to investigate the general process capabilities rather than to produce artistic creations. I agree that MDF is a good homogeneous material to work with but burning the resins is a sticky smelly business as you will find out when your machine arrives.
Best regards
Russ
I'd suggest relieving the tube of instantaneous power ups/downs in wattage.
I can't say if the electronics would be at fault or the tube.
But a latency in the etch as well as the heat of the material could possibly be at fault.
For example the star shape ...
If your machine was programed to simply cut a star within a star within a star (etc) at different shades of grey.
Rather than using linear typewriter type motion at the head ... The results would be significantly different.
Multiple passes could be applied to tackle depth issues.
Just a thought.
If your design looked more like a topographical map ... then ...
Hi I understand that a series of contour lines would produce the best results and that is effectively how they generate those decent images that carve so well. However, I am not trying to find workarounds, I'm trying to firstly understand how the machine works and if there are problems with instantaneous wattage control then I'm out to find out why. Although the PWM system is used to control cutting power, I think there must be a lookup table within the controller to deal with the 256 grey levels at 500mm/s That's something else I want to check out. Just how responsive is it
Thanks for your input it's always good to get stimulating ideas.
Best regards
Russ
If you ever entertain the idea ... It's a video I'd love to watch.
I have no idea how a picture of a horse for example could be converted in such a manner.
It may be a futile exercise.
Sadly I think all these models are produced from raytracing real 3D objects. Its the amount of reflectance off the surface that you are trying to map. Imagine a mirror polished round tube If you fired a beam of light onto the surface and measured how much light was reflected back at you. On the surface closest to you there would be 100% but as the tube curved away from you, more of the light would scatter sideways and there would be less and less refelectance. That's the principle.
Russ
Hi Russ
For me, it looks like you maybe are using a lens with to long focal distance, but most of all, look at the uneven lines in the bottom of the engraving, it look like there is a setting wrong somewhere, something with line spacing, resolution or something like that. Would you mind sending me the same file, so I can try some experiments when my machine arrives. I think it is good if we actually are using the same file to compare and exchange results. Just the original one, please. Wow 3 weeks is a looooong time :(
Hi Klaus
Unless I mention it in the video I am always using my favoured 1.5" lens. The line spacing was 0.1mm default but I know I can improve the finish with more overlap. However I never got round to that exercise yet because I became distracted by the VERTCAL lines which were a real puzzle. I'll soon get back to playing with the finer points to get the best result, even go as far as multiple passes.
Best regards
Russ
hi, love your tutorials, just got into laser cutting from a 3d background, just want to say these grayscales are called bumpmaps, as in 3d texture.
Hi
Thanks for the kind words and also for advancing my technical vocabulary. A very descriptive term......I like it.
I was surprised to find that that this little machine could eve do anything as clever as 3D carving. At the moment it's nothing like the pro machines but I'm hopeful that with more experimentation and understanding I shall be able to achieve passable results.
Best regards
Russ
Nice, have you tried the curves feature in Photoshop?helpx.adobe.com/photoshop/using/curves-adjustment.html
its a good way to play with intensity of shades in an image.
+Adomas Povilianskas
Hi Adomas
Thanks for your suggestion. I didn't go too far into Photoshop for fear that many people may not own it. Most bit map painting packages have a fountain fill or gradient fill and I wanted to demonstrate that what your eye sees and what the machine produces are not the same thing. You need a very distorted grey scale image to produce a pleasing result. I'm not sure Photoshop has any tools for doing this sort of grey-scale distortion. Take a very simple example of an O-ring or a torroid. If you 50% sink it into a surface you get a letter "O" with a semicircular section projecting. I can clearly imagine that to convert this shape into a 3D the grey scale render needs a grossly distorted and non linear compression of the scale towards the inner and outer edges and can't visualize any tools for doing that in Photoshop. BUT....I play with an old CS2 version of Photoshop and am certainly NOT an expert user.
I have now explored 3D laser woodcarving enough to realise it's possibilities and the difficulties involved and I am amazed that I was able to get this level of results from this cheap Chinese machine. The strange regular striations in the deep cut background are a bit puzzling and I may spend some time trying to find out why that's happening.
Thanks again for your input
Best regards
Russ
256 shades of grey... lol
LOL! I only get 50.
Hi SarBar ... this is Mike from Bavaria
Great Vids you produce over here ... best Training for Beginners with that machine i guess.
I tried that greyscale engraving and tested the Method Russ mentioned ... so here is what i got with my 2" Lens and original 50W Tube ... i found out that with direct output (which also means do greyscale) th USB is too slow to get the Data in Time ... so i have to transfer the job first via "download" which means actually upload to the machine and start it from the file menue then it works good ...
settings:
up.picr.de/25245853sg.jpg
engraved on plywood:
up.picr.de/25245862ei.jpg
+Mike
Hi Mike
It looks like you have achieved a pretty good photo rendition with grey-scale scanning. I did try this but was not very successful. Perhaps I should experiment a bit more now that you have shown me what's possible.
I always work with a USB file transfer into the machine and I admit it took several minutes to load some of the engraving programs. None failed.
Thanks for your feedback
Best regards
Russ
+SarbarMultimedia
so i just took it a bit more ...
so i now use 8-30% and about 180 mm/s to have a good Portait on Plywood ... 2" Lens ... i guess your 1,5" is better for cutting ... i will try a 3" Lens just to see what happens ...
so keep trying Sarbar i like your vids very much
+Mike
I am just working on a new Picture to Laser so far i can see you will have to think your conclusions over ...
The main thing is that the picture you want to engrave has to be greyscale and (this is really important) has to have real white parts in it ... so you need a really good contrast and bright white perhaps some gamma will help ...
+Mike
Hi Mike
Yes. I have a "60 watt friend" in the USA who is an electrical wizard. He has looked at the PWM signals and the power output signals to the laser tube and reports that white will always be zero power. If you set your power min to say 10% and your max to 60% then white (RGB 255,255,255) will be zero power and then the remaining 255 steps of grey will be spread across the min/max range. In this example the 10% power is only 2 or 3 watts so there will be a nice steady progression across the grey range.IF however, you were to chose min=40% and max=60% then the 255 steps would be divided across this 20% power range and the step between white and the first grey level would be HUGE.
Still a lot more playing to do. Thanks for the feedback
Best regards
Russ
That is not exactly what i mean ... will take some hours to complete the Laserjobs i am working on so i can show you ...
i made a temporary email account for you
so we can send us the mails more privat if you like to
MJB-W8pro@kabelmail.de