RDWorks Learning Lab 82 Intagilo and Rilievi
Vložit
- čas přidán 28. 10. 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
Thanks for the information, I have watched it twice ans surely will look at it again. Good information unavailable otherwise. Like your style of teaching too
Excellent video. Watched every second.
As the problem is the same with the old and new belts maybe it's worth replacing the pulleys with some true round ones and see if there is an improvement
That's a beautiful card! Lovely work.
Agreed! Any chance of getting a copy of it?
Great video Ross. As you I've experimented with belt tension and on my machine, I've found that it also plays a role on the friction of the axis, a loser belt produces less friction tighter more. Funny that as much issues as my stepper motors have with resonance, my current combination of pulley (HDT 24T 3M) and toothless idlers don't give me any of the "curtain" effect your are seen in your machine.
A greater friction may introduce some more problems driving the gantry and head. So indeed belt tension is a matter of trade offs. A loser belt will help tame resonance and give you cleaner cuts, but depending on your setup it can also bring backlash, a tighter belt may reduce backlash and give you more precision, but you may end up with serrated edges due to the increase in resonance.
As you know my main concern is quality, so I'm investing on Clearpath servos that should arrive next week. They should allow me to increase the belt tension to reduce backlash and thus, precision at high speeds, while getting rid of resonance all together.
Hi Abraham
I have just taken delivery of a second laser (400x600) that is servo driven. This means I may be able to do direct comparison tests . I say may, because its so much a better machine with a completely different manner of gearing the motors to the belts that I anticipate those comparisons will not be like for like. I don't actually need a second machine because unlike yourself, I don't run a business. However a great opportunity floated by to trade my video skills for a a partial investment in an amazing machine deal.........I just had to say yes. All will become clear in a couple of weeks when I start working with the machine.
Regards
Russ
Great news Ross!, just in time for the arrival of mine!, very exited for the new videos. Servos seems like a lot of fun.
I see you haven’t solved that issue with belt. I am gonna try to solve it tonight. I am having those waves pretty much exactly in a form of belt teeth.
Could the curtain effect be caused by how the teeth mesh with the pulley... as it enters the pulley it's having to force itself into the grove and pop out again on the other side causing the laser head to bob a bit. Thanks for posting I know a video like this had to take two to three hours!
Hi
The fact that the pulley only has 16 teeth makes the tooth form very exaggerated. I suppose the closest I can explain to you is it is a bit like running a belt round a square wheel. I'm sure you can imagine the belt motion would be VERY erratic Well this belt is really only fully engaging with about 6 teeth Or 6 CORNERS.whereas the square has 2 corners engaging. I think this problem has to imagined in those terms. OK in this pulley there are 16 CORNERS and 16 flats but as the belt moves off a corner onto a flat it effectively accelerates whereas when it passes over a corner it decelerates. The more teeth on the pulley the less this effect will be. So I hope you can see from this simple analysis that I am on a looser unless I want to change the whole system ratio. So in answer to your question I'm sure it's not the engagement of the tooth form that's the problem, its the fact that the pulley is really a polygon.
Best regards
Russ
As Dark Alchemist replied above, it is well known in the 3D print arena - my little machine suffered badly until it was rebuilt. One trick the 3D players use is where the belt runs over an idle roller, twist the belt 180deg so the idler only sees the smooth back of the belt - this is with 5mm wide belts though so i doubt but will work on a 15mm belt. I would replace that wonky drive pulley too :)
So to sum up what are the best settings for getting the ramp effect?? I need to know this because it's essential when making rubber stamps
It depends on how deep your engravings are. The smaller the font the smaller the ramp. If you choose a ramp value, you can see what effect the ramp has by previewing your file with the little blue monitor screen on the top tool bar
Best wishes
Russ
also check the wheels for guiding the axis. Like I said I'm good with printers and those marks on the printer is the wheels to tight or loose.
Hello, thank you for your Video. I have a question. If I set the mode to x-swing, then lasert he the text twice at a distance of 1 mm. The result Not good he made it Twice. If i set the Mode auf x-unilateralism, he is very Slow but it is Perfect. Why he made so Problem at the x-Swing ?
Hi
It could be one or two issues that you are fighting. The most likely problem is incorrect wiring to your HV power, supply. I know it sounds improbable but let me guess that your laser tube bears a label saying K H Laser?
If so then you need to use the You Tube private message system to send me your email and we can talk further because I shall need a couple of pictures.
Best wishes
Russ
What do you think would happen if you were to turn the belt so the teeth were on the outside? I know you'd get some slipping, but it would eliminate the interaction between the gear teeth and the belt teeth. It might be interesting to just try it and see what happens.
Hi Doug
Been there and done it. See
czcams.com/video/B87ifTPKN8c/video.html
Best wishes
Russ
In the previous video, the drive pulley on the motor looked terrible. Wouldn't it be worth replacing it with a well-made one. This should at least solve the problem with the 40mm wave length.
Since you put a new belt on and the problem remained it has to be a pulley. Given that the pulley obviously wasn't made very well it's possible that the tooth profile isn't how it should be. I suggest replacing both pulleys with good name brand ones. I'll bet the issue disappears
Great video, very informative. I have a question for you I hope you can help me figure out. I am trying to engrave text (fairly simple) but instead of engraving the inner part of the letter (filling the inner park of the letter), it outlines it instead (cutting around the letters). I've tried changing fonts but it continues outlining the letter. Can you make a video tutorial regarding this issue.
The only reason your letters are not engraving is that you must have a frame of some sort around your text. You also have the frame and text on the same layer. Two reasons for your issue.
czcams.com/video/ybnT3lECAqs/video.html might help you
Best wishes
Russ
Are you sure you are in scan mode rather than cut?
I wonder if your pulley has the wrong teeth for the belts
Hi Russ, I am having exact same issue on my new machine. K40 did not have this issue at all, for the record.
You just discovered what we even see with 3d printing and that is a toothed belt should never run over a smooth surface so replace all bearings touching the belt with GT3 pulleys (matching your GT3 belt) and it should fix it up.
This is harder to make as you must use a smooth rod inside the pulley and a bearing on each side with a spacer between on each side so the pulley can spin. It should take care of the curtain effect.
This makes a lot of sense, but I guess it also depends on the width of the toothless idler/pulley. on my system they are around 72 mm circumference and the "curtain" effect is not as noticeable if ever present. I think the reason manufacturers go with toothless pulley is 1. Cost 2. it makes tension the belt easier, if you go toothed, your alignment needs to be essentially perfect so that the belt has the same tension on both sides.
Abraham Saenz
Alignment has to be perfect which is dang easy to do. The same tension on both sides? How would that be an issue? We are already starting to have pulleys instead of bearings and the tensioning systems remained the same. If they have a machine with bearings people will, as I did, twist the timing belt so the flat side comes in contact with the bearings and the toothed side is only touching the gear on the stepper motor and that works as well.
I guess it depends on the drive system. On my machine, you adjust the tension with screws on the belt itself, The screws are located on top, since my pulleys have no teeth the tension is spread evenly across the belt, its an open belt. In my Y axis motor however, drives a toothed pulley, when I tension the small (270 3M 15mm) belt I have to be really careful making sure both sides of the belt are equally tense. Tension to that belt is exerted pulling the actual motor to the opposite side so its not that difficult (loop belt), however, if the tension system on the belt itself, it would be a nightmare.
With my crude little machine it may not be as simple as that. I have thought more about the problem and there is a further rambling I have just posted. As always, I appreciate your input from a different perspective. Never forget I am still learning and I'm happy to pick up tips from any source.
Best regards
Russ
Abraham Saenz
On any 3d printer that isn't normally the case as only one side needs to be tensioned.
try transform text in curves if necessary you can combine to make one object from 2 or more (not make group) the first group of text and combine separated the second group of text its convert the 1º text sequence in object.
In Corel Draw (i dont know how do this in you software) select the text, press ctrl+q
or
crtl+q , select the texts and pres ctrl+l to combine many blocks of objects
Hi Eduardo
I don't use CorelDraw. I'm an old-school engineer with little artistic talent so a creative drawing package is wasted on me. I convert everything to DXF vector files and work in my trusted CAD package where the sort of tricks you describe are not possible. I can do everything but it has to be done a different way.
Best wishes
Russ
SEE & LEARN
White belts will cause that. Change to black rubber belt, it will go away. Has to do with flexibility
Hi Vlad
Sorry to report it's not as simple as that. Timing belts were developed to replace cam shaft drive chains in engines where you need to transmit POWER in ONE direction. They have been hijacked for CNC use where you need a cheap method of positioning low mass objects. You get 95% efficiency of proper engineering solutions (such as ballscrews and rack and pinion)at a fraction of the cost.
see czcams.com/video/QFLq14vY2zQ/video.html to begin understanding deficiencies of tooth drives.
see czcams.com/video/SsSFVTAhng4/video.html to see why I changed AWAY from a black rubber belt
and czcams.com/video/B87ifTPKN8c/video.html to see how I completely fixed the problem
Best wishes
Russ
SarbarMultimedia I tested different GT2 belts, because I was researching the subject for my business. White (PU) belts turned out to be a very bad choice for our cnc machines/3d printers, due to small diameter of pulleys and PU material being too hard. I did have different artifacts until I swapped back to my Carbon fiber reinforced GT2 rubber belts, which is much softer and it did the trick immediately. Your issue probably was not caused by belt alone, so I can’t comment on anything else. Just thought to share my observation.
SarbarMultimedia regarding the link about belts, I briefly watched through that video. Seems that you are not talking there about GT2 belts that are designed for cnc application, but rather about standard timing belt models that are totally not designed for cnc. I only use GT2 for such purposef. Never even tried standard timing belts, they are not designed for precise linear motion like that.
how can I send you an email my wife and I are having some troubles and could use your Help please
Hi Ron
I AM NOT A MARRIAGE COUNCILLOR OR SEX THERAPIST!!!!!!
I'll send you a private message with some great tricks to try.
Regards
Russ
Well we moved and we get a message on the machine frame slope work paused. That is the first problem. The second is we can't get the machine to start in the left corner it always starts in the middle towards the right side.
Hi Ron
The reason for your error will be that part of what you are trying to cut is outside the work table. The reason for this can be can be because of the other problem you describe.
Several questions
1)Which back corner does your machine run to on start up?
2)In RdWorks Config system setting....which mirror boxes are ticked? and where is the little HEAD POSITION marker?
3) What size is your bed and have you set it the correct size in Config page setting?
4) RDWorks screen bottom right there is a position window. Have you got CURRENT selected? (my guess is you may have this set to ABSOLUTE)
5)what size is the job you are trying to cut(or is it scan?)
This will do to start with
Best regards
Russ
ps did you get my email address?
I apologize for the very late response. I've been trying to figure out the communication error we get. I never did get your email address
The pulses/distance parameter is incorrect in your stepper controller ,,, has nothing to do with the belt ....
Thanks for the comment . You do not offer any logical reason for how a stepper motor can make regular 3.5mm pitch marks. You need to first understand how those marks are created. The power from the laser is constant because the current through the tube is set as a constant. The depth of burn should therefor also be constant IF the beam velocity over the worksuface was also constant
. It is logical therefore to interpret this varying depth of cut that you see here, as varying beam velocity. The slower the beam travels the deeper the cut. I fully understand that the stepper speed is not constant but micro stepping in a series of VERY SMALL stop starts. The effect of those mini pulses decreases as the speed of motor rotation increases and the inertia of the rotor starts to dampen those pulses. Just look at the colour of the beam marks and depth of cut and put a rational explanation of how they can be stepper generated.
If you watch czcams.com/video/QFLq14vY2zQ/video.html you will see my logic for attributing these marks to the timing belt .
Then if you watch this session czcams.com/video/B87ifTPKN8c/video.html you will see me magic those marks away without touching the stepper motor.
My explanation above is not intended to shout down your comment. It's perfectly valid because it is a natural instinct draw a conclusion from immediate visual evidence. Sadly my training as a young engineer (the old school way) engendered a healthy mistrust of what I saw with my own eyes. It was drummed into me "never assume" and that " understanding a problem is 50% of the solution". I hope (with no criticism intended) that you can see this is more than a skin deep problem
Thanks again for allowing me to explain this to others that may read your comment
Best wishes
Russ
The stepper speeds up and slows down as it travels from step to step , even while using microstepping , because natively it is a 200 step motor and performs better around where the native poles are ...but I digress ,, I was referring to the error in overall distance of the cut is related to the distance multiplier applied per pulse....
The stepper has 200 places it "likes" to be ... away from those places will be slower , toward those places will be faster ....regardless of the speed , direction or "microstepping" .... a higher PPR motor or gear reduction can dilute this effect ...
@@vittoriosilva1454
Just look at the math. 200 steps /16 teeth per revolution means 12.5 steps per tooth. Please explain how that can produce my pattern.
Best wishes
Russ
On second thought , it is the belt .... tightening it pulled the teeth farther apart ......causing it to no longer mesh correctly with the pulley ...The belt should not be that "stretchy"....