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Sep 05, 2019, 12:35 PM
Registered User
Quote:
Originally Posted by timomo
Hi, I am currently building this machine, and I encountered a problem. Even when I set the steps per mm for all four axis the same, only two motors work. Its my first project of this kind, and I really don't know much about software and computers in general, so it would be nice if some of you could help me out.
I assume that you use Ramps V1.x board. Do you have microsteps settings (Jumpers below the stepper driver circuits) set up for the same settings of all 4 drivers?
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Sep 05, 2019, 02:04 PM
Registered User
The current settings are adjusted by tiny potentiometers on the plug in stepper boards. There are plenty of youtube videos on how to set these for the variety of driver boards that can be used.

However if the X and U motors still moved when you swapped the drivers, they are all working and the problem lies elsewhere. Maybe the g code is commandng the wrong axes for Z and Y? . Check the commands sent by the GRBL sender on the PC to the ramps boards.

If this is correct then there is something amiss with the ramps board., so check the soldering etc on the board.

I don't suppose anybody in the forum lives close to you and can give some physical help?

regards JH
Sep 15, 2019, 07:59 AM
Registered User
Quote:
Originally Posted by rasciodc
BTW, just a little poll here. What software are you guys using to generate the GCodes?
As mentioned earlier I started writing a program in java ( Using the Drela document you shared ), there are still some small improvements to be made in the user interface, but I will post the end result soon.
Last edited by dodo3441; Sep 15, 2019 at 08:12 AM.
Sep 16, 2019, 04:40 AM
I hate propellors
emufingers's Avatar
I amusing the drela excel program (7.0) I have found the it is difficult to get accurate wing pairs. The length wise flipping of the wing leads to different kerf effects on the left and right wings even if the panel is centered on the wire. The effect is greater as taper increases.

I am working on flipping the wing so that the root stays on one end and the section is inverted.( like GMFC)

The cutting sequence is the same for wing one but wing 2 is cut from the same side of the block as wing1 cutting the bottom as the top and then then top as the bottom, back to the trailing edge.

This means a tapered block can be used as well.

The process involves reordering the .dat file.
Sep 16, 2019, 12:35 PM
Registered User
Can somebody please answer? My Grbl doesn't safe the steps per mm, so my two motors don't work. The default had diferrent numbers for x and u axis than it had for y and z axis. Someone can tell me that, right?
Sep 16, 2019, 12:45 PM
Registered User
Sorry, didn't see the next page. But how do I change the grbl settings. I am using grblhotwirecontroller to give stepper motors a manual command like X+ , and only x and u work. I have also tried loading the gcode, and it did work, although only on x and u axis. the x and u have 67 steps per mm and y and z axis have 1500 steps per mm. I did succeed in changing all of them to be 67, on the grbl serial monitor, but it seems like it doesn't save them. grbl just writes ok, and then I open the hotwire controller, or just close the grbl serial monitor and then open it up again, and the numbers are back to normal. I have tried sending my changes to arduino, and then uploading the grblmega2650 again, but that doesn't change anithyng.
Sep 16, 2019, 07:56 PM
I hate propellors
emufingers's Avatar
Quote:
Originally Posted by timomo
Sorry, didn't see the next page. But how do I change the grbl settings. I am using grblhotwirecontroller to give stepper motors a manual command like X+ , and only x and u work. I have also tried loading the gcode, and it did work, although only on x and u axis. the x and u have 67 steps per mm and y and z axis have 1500 steps per mm. I did succeed in changing all of them to be 67, on the grbl serial monitor, but it seems like it doesn't save them. grbl just writes ok, and then I open the hotwire controller, or just close the grbl serial monitor and then open it up again, and the numbers are back to normal. I have tried sending my changes to arduino, and then uploading the grblmega2650 again, but that doesn't change anithyng.
Check the early discussion in this thread There re several posts on this .You need to change a setting in the config.h file nd recompile your grbl on the arduino. . The default is not to save settings.
Sep 17, 2019, 07:42 AM
Registered User
I think I did that now, I mean I did change default.h to be 67 steps on all motors, and then uploaded the grbl on to Arduino again, but the serial monitor, and hotwire controller still shows the old numbers.
Sep 17, 2019, 09:56 AM
Registered User
Quote:
Originally Posted by timomo
I think I did that now, I mean I did change default.h to be 67 steps on all motors, and then uploaded the grbl on to Arduino again, but the serial monitor, and hotwire controller still shows the old numbers.
I think there was some setting in the arduino code that you have to change so that it doesnt always use defaults. It was mentioned somewhere in this thread for sure.

Quote:
Originally Posted by emufingers

I am working on flipping the wing so that the root stays on one end and the section is inverted.( like GMFC)

The cutting sequence is the same for wing one but wing 2 is cut from the same side of the block as wing1 cutting the bottom as the top and then then top as the bottom, back to the trailing edge.

This means a tapered block can be used as well.

The process involves reordering the .dat file.
Thats what I did too, less foam use and kerf is identical for both wings. Also separating the block horizontally gives you identical "shells" to use for Building. Best approach imho.
Last edited by dodo3441; Sep 17, 2019 at 10:05 AM.
Sep 17, 2019, 12:48 PM
Registered User
Quote:
Originally Posted by timomo
Can somebody please answer? My Grbl doesn't safe the steps per mm, so my two motors don't work. The default had diferrent numbers for x and u axis than it had for y and z axis. Someone can tell me that, right?
Hi,

In sources file, change config.h at line ~ 50

#define ALWAYS_DEFAULTS_SETTINGS 1 /// 0 normal

to

#define ALWAYS_DEFAULTS_SETTINGS 0 /// 0 normal

And your settings will be saved .
Sep 17, 2019, 04:04 PM
Aom
Aom
Registered User
Hey guys. Wanted to build a cnc like this for ages, and since it seems like i've made it through the toughest semester at school, i think i can "afford" to play with this as a side project...

I have some questions though!

1. Could i use ramps 1.6? The pinout is supposedly the same. While im at it, could i use the MKS GEN L v1 board? It has the benefit of the atmega being incorporated on the same pcb if im correct. Im very new to electronics and coding...

2. As many of you have stated, accuracy is not the same here as in a cnc mill for example, but i still have some degree of paranoia when i see stuff like mdf and drawer-slides, i blame it on being a former CAD/CAM programmer and machine operator.

DODO3441 made a really neat design which i would like to try, but seeing as im too poor to build this machine twice, is it worth it to go "all-out" on linear components attached to alu extrusions, like ive seen somebody else do, or is this mix of DODO's construction materials viable? Im a student so my budget must not exceed something like 300euros...

3. Have any of you experienced problems with nema17? Im very uncertain about going for nema23, because generally thats where the ramps board will bottle neck, to my understanding.

4. Ballscrews, leadscrews or pulley/slider? (I think im going for ballscrews)

5.Since the budget is key here I will be ordering the most part of the build from banggood, since they seem to have almost all parts im looking for, any experiences here of their linear rails and or electronics, as in the atmega and ramps clones.

Many thanks for this thread, I stumbled upon this via Keith Howlettes videos on cnc wire cutting. Originally i'd thought about using a manual bow with weights and pulleys but i felt sick just thinking of all the crappy templates id make for my wingprofiles... Just love cnc!

Regards/A
Sep 17, 2019, 04:26 PM
Registered User
Quote:
Originally Posted by Aom
Hey guys. Wanted to build a cnc like this for ages, and since it seems like i've made it through the toughest semester at school, i think i can "afford" to play with this as a side project...

I have some questions though!

1. Could i use ramps 1.6? The pinout is supposedly the same. While im at it, could i use the MKS GEN L v1 board? It has the benefit of the atmega being incorporated on the same pcb if im correct. Im very new to electronics and coding...

2. As many of you have stated, accuracy is not the same here as in a cnc mill for example, but i still have some degree of paranoia when i see stuff like mdf and drawer-slides, i blame it on being a former CAD/CAM programmer and machine operator.

DODO3441 made a really neat design which i would like to try, but seeing as im too poor to build this machine twice, is it worth it to go "all-out" on linear components attached to alu extrusions, like ive seen somebody else do, or is this mix of DODO's construction materials viable? Im a student so my budget must not exceed something like 300euros...

3. Have any of you experienced problems with nema17? Im very uncertain about going for nema23, because generally thats where the ramps board will bottle neck, to my understanding.

4. Ballscrews, leadscrews or pulley/slider? (I think im going for ballscrews)

5.Since the budget is key here I will be ordering the most part of the build from banggood, since they seem to have almost all parts im looking for, any experiences here of their linear rails and or electronics, as in the atmega and ramps clones.

Many thanks for this thread, I stumbled upon this via Keith Howlettes videos on cnc wire cutting. Originally i'd thought about using a manual bow with weights and pulleys but i felt sick just thinking of all the crappy templates id make for my wingprofiles... Just love cnc!

Regards/A
I cant speak for the other options but I'm happy with mine. No mechanical issues so far, software is the annoying part here haha. Spent 120€ on the whole project. ( Got some parts like the stepper motors second hand) Personally I think linear rails would be overkill on such a machine, since there are no cutting forces like on a mill. If you use the version with a bow the whole construction basically just carries its own weight, same reasoning is why i went for cheap nema17 style motors.
Sep 17, 2019, 06:08 PM
A.K.A sir Crashalot
methuso's Avatar
Aom. just a heads up, You might be luckier.
I've ordered 2 rails (Machifit MGN12) from banggood and have 6 carriages for them where one carriage is too loose and the other 5 is just grinding or too tight too trust a nema17 to move.
I have disected them and cleaned them, run them dry and with "proper" grease we use in $M- machines at work. (yeah. im a machinist)

On the otherhand ive designed an printed my Foam cutter which ive posted on thingiverse. I use M8 as leadscrews wich seems good enough. you could use 2 nuts with a firm spring between them as antibaklash nuts. And I use 8mm and 25mm rods with lm8uu and lm25uu bearings for moving things around.
This is overkill and i have some binding. Drawerslides will do.
I think i will design another one using teflontape for sliding and gt2-belts for moving stuff, just because making stuff is fun.
Sep 18, 2019, 12:42 AM
I hate propellors
emufingers's Avatar
Quote:
Originally Posted by dodo3441
I think there was some setting in the arduino code that you have to change so that it doesnt always use defaults. It was mentioned somewhere in this thread for sure.



Thats what I did too, less foam use and kerf is identical for both wings. Also separating the block horizontally gives you identical "shells" to use for Building. Best approach imho.
Spot on. That will make building easier.
Are you able to share your java app?
Sep 18, 2019, 03:50 AM
Registered User
Quote:
Originally Posted by emufingers
Are you able to share your java app?
Ill make a new thread here in the forum once it is finished, currently busy with exams but should be ready in a few weeks.




I attatched the current unfinished version, still some little bits to improve on the user interface. Just double click the jar file and it should run. set up the machine settings in the settings tab and then import your arfoils and the rest is self explanatory i hope. Press enter after changing variables to update the graphs, calculate buttons do the same thing. There are probably still some bugs so feel free to test it. I'll use the feedback to fix everything before sharing the final. ( reccomended value for cutting points & distribution coefficient are 500 and 1.5 increasing the number or density of points too much will mess up the cut path, i might just remove those settings for the final)
Last edited by dodo3441; Sep 18, 2019 at 03:59 AM.


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