Show all posts by user
Safety...
I haven't seen many places that use the nomenclature 2GT - almost everyone uses GT2 which is the designation Gates uses (GT is a Gates trademark). I believe Gates refers to the belts as GT2-2mm, GT2-3mm, GT3-2mm or GT3-3mm.
by
LoboCNC
-
General
Can you post a link to the GT3 data you read regarding backlash?
Also note the "3" in GT3 or the "2" in GT2 does not refer to the pitch, it refers to the tooth profile series. (You can actually get 3MM pitch GT2 belts.) The tooth pitch is called out separately.
by
LoboCNC
-
General
Quotethe_digital_dentist
It isn't just belts causing ringing- the motors themselves also contribute, possibly more than the belts.
You can test the effects of motor stiffness on ringing by adjusting the motor current - higher current will increase the stiffness and should decrease the magnitude of the ringing and increase the frequency. I tried this on my largish (350x350mm) H-drive printer and
by
LoboCNC
-
General
A lot of the reason for ringing is that many printers use really high acceleration and "jerk" parameters which excite the ringing. Setting high accel and "jerk" values creates something closer to a constant velocity, which in turn minimizes the over/under-extrusion when you go around sharp corners due to the hysteresis in extrusion process. Essentially, there is a trade-off between over/under-e
by
LoboCNC
-
General
Quoteshortyski13
I'm looking for a rather large (2138mm to be exactly, obviously bigger is okay, just not smaller) gt2 closed timing belt to run the pulleys for the bed raising/lowering on my large printer corexy design. I have to admit, i didn't expect to have the issue of not being able to find a large belt. Does anyone know where I can get one, or how to convert an open pulley into closed th
by
LoboCNC
-
General
QuoteElmoC
Patents and Copyrights are two different beasts. I can't speak to the case you are referring to, but it doesn't sound likely. There had to be more going on than that.
An example of one of these weird cases was with Weight Watchers. They have patented their point system so anyone can get the algorithm by pulling up the patent. There were some programmers who wrote some smartphone app
by
LoboCNC
-
General
QuoteElmoC
If it is all off the shelf parts, not a problem as long as you don't include the instructions. Think of it this way. Someone designs an all wood dresser and licenses it as non-commercial. Does that mean no one can now sell a package of wood and hardware that can not only be used to make that dresser, but any number of other items?
If there is nothing unique about the item, then how
by
LoboCNC
-
General
QuoteElmoC
Nothing gray about a kit of off the shelf parts. Not a violation. It's when you add project specific parts you get into the gray area.
What about a design that consists entirely of off-the-shelf parts put together in a unique way? I don't think there's any logical restriction that a unique design must contain at least one unique, project specific part.
by
LoboCNC
-
General
Quotejinx
take this example TANK
first ten backs the project helps fund supplies for the next 10 products or so then prepares a build manual which is then what! sold on by you/site, have you the creators consent to sell something to which they applied a License with a NonCommercial aspect of the License. just wondering how that works.
This is really quite a tricky question. With the Tank
by
LoboCNC
-
General
I've had this problem on occasion, where it tends to yank the spool right out of my spool holder. One thing that might be going on with old filament, there is a secondary crystallization process that happens with PLA when annealing at ~80 deg.C that makes the filament stiffer, more brittle and also increases its softening temperature. I would imagine that this crystallization also takes place,
by
LoboCNC
-
General
Back in the day when I was working on clean room automation, I remember instrumenting motors with accelerometers and measuring the vibrations in a belt drive system at different levels of microstepping, up to 1/256 microstepping. The difference between 1/8th stepping and 1/16th stepping was incredibly small, and we couldn't measure any difference beyond 1/16th microstepping. What was a much la
by
LoboCNC
-
General
What McMaster part number were you ordering for 5mm rods? Did you look at the linear shafting (6112K13) which has a 0.03mm/300mm straightness tolerance?
by
LoboCNC
-
General
QuoteHugoW
Thanks for all the input. I've just bought aluminium rods instead of the steel ones for the moving X axle, reducing weight considerably. To keep things simple, I plan to use these:
Any comments? I like it to be spring loaded as it keeps tenstion, but I wonder if it is stiff enough.
Cheers,
Hugo
As long as you don't exceed the bias force of this type of spring, it won't add any ad
by
LoboCNC
-
General
Quoteo_lampe
Does your M-code also tell about coordinates of the axis or is it just a busy signal?
It would be enough to know the final coords of the actual move or raise a pin that tells other controllers a move ends in the " collision zone " .
My code just returns a busy signal (e.g.: X1Y1Z0E1) with a 1 or a 0 indicating if an axis has anymore steps in its queue. The M114 command returns po
by
LoboCNC
-
General
QuoteVDX
... there is the option to set a watch-dog timer - use it for a heart-beat on an I/O-pin to get a "waiting" signal ...
Thanks for the help. Is this the M43 command? How would I use it and then read the I/O pin state through the serial port?
EDIT: Actually, never mind. I bit the bullet and hacked in a new M-code that reports back if X, Y, Z or E is actively moving. I'm happy to shar
by
LoboCNC
-
General
I'm trying to coordinate 2 marlin-based controller boards for a robot project and I need to be able to poll each boards to see when it has finished its current move. I haven't found any commands that simply tell you if the steppers are still moving or not. Any suggestions? (I know Marlin is not designed for this sort of thing, but I'm trying to get something going quickly with the tools I have
by
LoboCNC
-
General
One down side to the CoreXY, especially for a large printer, is the loss of belt stiffness with the really long belt lengths involved. The mass of a large carriage makes the belt stiffness even more critical. You might want to go to 12mm wide belts if using 2mm pitch, or maybe jump up to 3mm pitch belts, which are a lot stiffer. Here's a link to a Gates datasheet listing comparative belt stiff
by
LoboCNC
-
General
QuoteJamesK
I remember when you were first building it there was a concern about how failed prints might make a mess over the hot-end - the inverted spaghetti monster problem. How has that worked out, have you had any print failures to deal with?
I've only had a couple of spaghetti monster failures and they've been no better or worse than with my other printers. I did add a silicone shield over
by
LoboCNC
-
General
QuoteMechaBits
Considering the amount of plastic parts in there(even though its a minimal setup), and the size, it looks like a fairly good print, So is print just on kapton or a build surface, is that example pla?
I've been printing mostly with PLA on kapton tape, for more than 6 months now without problems. Note that all the important bits (the high-speed X-Y mechanism) are metal and stuck to
by
LoboCNC
-
General
QuoteMechaBits
Sorry forgot about that one, yeah cool to have that large print hanging upside down, from just 2 rods and using just wire, seems quite large too, is it 300x300 for bed
Actually, 350 x 350mm. I used 400mm rails.
by
LoboCNC
-
General
QuoteMechaBits
QuoteLoboCNC
Or there's this: Inside-H drive
So what does this do? Where does the filament go?
presume your going to filp it, but cant see how you will feed it.
Filament is fed in at a right-angle. This particular printer prints upside-down, but you could also configure it to print right-side-up.
Here's a video of the full printer:
https://www.youtube.com/watch?v=hdju_6XEHZ4
by
LoboCNC
-
General
Or there's this: Inside-H drive
by
LoboCNC
-
General
Quotetobben
How long will it take before the PTFE sleevings need replacement? From what you have observed so far, do you think it will be closer to 100 or 1000 or 10 000 print hours?
It's a neat and cheap solution, I've been considering it for the Hangprinter =)
That's a good question. It doesn't seem like the PTFE is showing significant wear, but to be honest, I've probably printed less than
by
LoboCNC
-
General
Quotebesenyeim
This forum thread ispired me to build something similar. I probably will settle with the same design, but yet I'm just experimenting with materials and other kinematics. I bought some dyneema line, which is similar to spectra, and tried different materials to guide it. The best so far is enamel wire (originally for coil windings). This hard, slippery coating is better than just pol
by
LoboCNC
-
General
Note that you can always use the honeycomb infill pattern to create honeycombs automatically. Just print a rectangular prism with no top layers and no bottom layers and then select the infill density to give you the size honeycomb you need. This will print up much faster than an explicitly modeled and sliced honeycomb.
As for material, I'd go with unpigmented ("natural") PLA. It may not techn
by
LoboCNC
-
General
QuoteJamesK
But if you print moslty pla it's perhaps not the ideal surface. What do you use at the moment? I have some kapton that I never got around to trying, but it seems very delicate. I can't imagine it lasting for very long, which could get a bit pricey as well as annoying. Elmer's works well, but it does make a mess of the print surface.
I'm using kapton tape, but I'm very careful with it
by
LoboCNC
-
General
After sending JamesK some of the polyester sheet, I did a couple of PLA tests of my own - first on a tiny 2"x2" square and then on a full-sized sheet. On the small square, I tried breaking off the PLA part while the bed was still warm, and the acrylic adhesive just pulled right off the back of the polyester, leaving a gooey mess on my bed. After hearing of JamesK's success, I tried out a full-s
by
LoboCNC
-
General
It looks like the broken part is laser cut acrylic. If you glue it back together with cyanoacrylate glue, it will be almost as strong as new.
by
LoboCNC
-
General
Nicely done experiment! While you've got your setup going, what about doing a sample print with holes in it at various heights and then insert the thermistors into the holes. This would give you the internal temperature of the print vs. the surface temperature of this experiment. (And also make it easier to keep the thermistors in place
by
LoboCNC
-
General