Designing a new router called Brevis-HD

[mactec54]

Hi Mactec - I agree with all of that in principle. But the planner will turn 1000's of small lines into one line if it's a straight line. Do you use UCCNC? The 0.0002" is achieved by the tolerance settings not necessarily how small or long the polylines are set. Peter

3D and 2D contours are where you see the difference straight line machining does not count or matter, it's just a straight line

I have UCCNC but don't use it as there are better options, I buy and test all the different machine controls so have most of them and have tested them, I set everything at .0001" in cad Cam and any setting in machine controls, to achieve high tolerance machining, the .0002" is the finished part or mold which can be .0001" in some cases, the average general parts are always within .0005" (anything that does not matter) on the finished part sizing, and depends on which machine is being used, I set the polylines to .0001" and forget about it, it never changes, I get very smooth contours and corner machining, when you have matting parts .0002" is the max a part can ever be, or nothing will fit together, wood and plastic machining almost anything will work +/- .010" .25mm or more usually does not matter

[peteeng]

Hi Mactec - I'm trying to understand the behavior of UCCNC better as that's what I have. I will have a "fast" config and an "accurate" config. Obviously there are better controllers then UCCNC and their motion planners are more sophisticated and will produce faster/smoother toolpaths.

Most of my work is plastic/ timber so 0.25mm "accuracy" is fine. As I do 3D contour work I want that to happen as fast as possible. Will be interesting to see how F360 goes vs mecsoft and dxf workflows. Peter

https://www.facebook.com/ScootCNC/vi...27287467879047 my latest settings have improved the speed from 1000mm/min to 2500mm/min and I don't think the accuracy has suffered. but for things like this tray accuracy does not really matter....

[mactec54]

Hi Mactec - I'm trying to understand the behavior of UCCNC better as that's what I have. I will have a "fast" config and an "accurate" config. Obviously there are better controllers then UCCNC and their motion planners are more sophisticated and will produce faster/smoother toolpaths.

Most of my work is plastic/ timber so 0.25mm "accuracy" is fine. As I do 3D contour work I want that to happen as fast as possible. Will be interesting to see how F360 goes vs mecsoft and dxf workflows. Peter

https://www.facebook.com/ScootCNC/vi...27287467879047 my latest settings have improved the speed from 1000mm/min to 2500mm/min and I don't think the accuracy has suffered. but for things like this tray accuracy does not really matter....

Your Z axis retracks are too large if you use 2mm to 3mm this is more than enough, between engraved parts like this, it will speed things up, using a shorter cutter also will do a better job also

[peteeng]

Hi Mactec - Yes shorter retracts result in faster times but that's not the issue with this part. The tall retract is a function of the safe height setting in UCCNC. If I use a short retract and I move the spindle somewhere and I'm not thinking it may break the tool on a clamp. This has happened before. UCCNC has a general safe ht and a programmed safe ht and these can conflict depending if your in program or not. So I just set it high so it will miss my clamps anywhere anytime.

The tall tool is because that's what I had at the time in a 3mm tool. My short 3mm tool was broken in my last spindle just before the spindle broke due to it pre fail condition. My current interest is in 3D contouring fast and to tolerance. Peter

[mactec54]

Hi Mactec - Yes shorter retracts result in faster times but that's not the issue with this part. The tall retract is a function of the safe height setting in UCCNC. If I use a short retract and I move the spindle somewhere and I'm not thinking it may break the tool on a clamp. This has happened before. UCCNC has a general safe ht and a programmed safe ht and these can conflict depending if your in program or not. So I just set it high so it will miss my clamps anywhere anytime.

The tall tool is because that's what I had at the time in a 3mm tool. My short 3mm tool was broken in my last spindle just before the spindle broke due to it pre fail condition. My current interest is in 3D contouring fast and to tolerance. Peter

No, it is simple to do you only use the short retract when you are inside the work area then you use a safe Z height at the start and end of the program this takes care of any chance of crashing the tool into something

[peteeng]

Hi Mactec - Yes it sounds simple, and I understand the settings and have still crashed the tool when out of program when I use clamps "inside" the object perimeter when I push go to zero for instance..... So to stay "safe" I use a safe ht that misses everything in the general config and in the program height.

I've been away visiting family for a few days and been sketching various updates. I have decided to enclose Scoot for better dust control asap. Plus my next next machine will use belts on the long axis and I've always been unhappy with U drives but a long fully returned drive is not as stiff. But I have resolved most of my issues with the U drive so looks like a 30mm U drive belt is in order for the 3m long machine....called Lanky....Peter

[peteeng]

Evening all - Today I decided to do my first F360 CAM run. I had to make a couple of cleats for a full length mirror that will be used to support it on the side of a cupboard. So I designed them in F360 and did the CAM work there as well. Brought it to the machine and it plunged down into the billet due to a 55mm tool offset G43!! So tidied that up and seems F360 takes off at the tool height so then scratched the top of the part as the part top was (0,0,0). So added in a Z up move in the NC. After that all seemed good on part No1.... Part No2 I removed the G43 and did a little move and took my brand new 1F 6mm tool thru the screws that hold the part down. Damn... So Learning new stuff is frustrating. If I did it in uccnc or mecsoft would have been a dawdle... but I suppose in a few tries all will be understood.. Peter

Now Scoot is feeding faster I'm getting nice soft sawdust flakes and I can see the flakes leaving the tool in a nice stream. So now to speed it up again....

[pippin88]

I don't know UCCNC, but a go-to zero button / script should employ a safe Z level (usually full up) and should be quite separate to CAM generated code.

Quick googling: forum.cncdrive.com • View topic - Information on the goto zero function.

[peteeng]

Hi Pippin - It is as you say outside of the programmed move and UCCNC has a set safe Z ht in its config settings. My Z zero moves around depending on the thickness of the job and the thickness of its waste board. If you use a "high" safe Z it can lift the axis to its mechanical end creating the need for a Z reset. As I don't currently have limit switches on my machines. It can also lift OK but then travel in a straight line to 0,0. If there is a high clamp it may crash into it. Once you crash a couple of times and figure out the best strategy for you it's no big deal unless your brain is not switched on at the time. Which does occur occasionally I'm sure F360 will have little foibles as well. Peter

[mactec54]

Hi Pippin - It is as you say outside of the programmed move and UCCNC has a set safe Z ht in its config settings. My Z zero moves around depending on the thickness of the job and the thickness of its waste board. If you use a "high" safe Z it can lift the axis to its mechanical end creating the need for a Z reset. As I don't currently have limit switches on my machines. It can also lift OK but then travel in a straight line to 0,0. If there is a high clamp it may crash into it. Once you crash a couple of times and figure out the best strategy for you it's no big deal unless your brain is not switched on at the time. Which does occur occasionally I'm sure F360 will have little foibles as well. Peter

Z axis Home position and you work Tool Z0.00 is to different things, work or Tool Zero you use a G43 this is set in the tool offset page, if this is all setup correctly you will never have a crash

[peteeng]

Hi Mactec - The perfect world argument always wins, unfortunately myselfs and the UCCNC post in Fusion360 are imperfect. The F360 UCCNC post has tool compensation and G43 in it that I do not want. So A) I manually delete these or B) I learn how to modify or create a post in F360 for myself. Been a few decades since I've written a post... But that's what I'm here for... the challenges... So I've been through how UCCNC makes code via dxf and how F360 with the UCCNC post makes code and I'm filtering out the issues. I made the mistake of assuming the F360 simulation is what I will get wysiwyg. The post has extra lines in it for safe z ht and tool compensation that I don't want. So I'll have to pay attention to the code carefully until I get the post right ie step into that warm cosy, feather bed perfect world mentioned after learning a few things & probably bumping a few things. Peter

[peteeng]

Morning all - Matt was in the workshop yesterday doing more work on his build. He set up the gantry rails and the Z axis motion parts so its now ready for wiring and motors. All the mechanics are smooth, very happy with that.
He's finished his electrics "drawer" and I checked his wiring but no motor motion yet. I suspect its a faulty BOB. I called the supplier but he was adamant that the BOB would not work with UCCNC and that was the reason. I've built 2 other machines with this BOB using UCCNC so he's lost my future custom so I ordered one from OYOsteppers in CN. I'm ordering the shielded cable for the spindle this week and other cables now Matt has decided how to route his machine. Getting close to motion!

In terms of Brevis/YaG/Scoots development (over the last years, started in Jan 2020) ) its time to sit down and rationalise all the parts and decide if they can be reduced in cost or improved in performance. Matts build represents the end of Scoots development & the beginning of its production potential..... Peter

[mactec54]

Hi Mactec - The perfect world argument always wins, unfortunately myselfs and the UCCNC post in Fusion360 are imperfect. The F360 UCCNC post has tool compensation and G43 in it that I do not want. So A) I manually delete these or B) I learn how to modify or create a post in F360 for myself. Been a few decades since I've written a post... But that's what I'm here for... the challenges... So I've been through how UCCNC makes code via dxf and how F360 with the UCCNC post makes code and I'm filtering out the issues. I made the mistake of assuming the F360 simulation is what I will get wysiwyg. The post has extra lines in it for safe z ht and tool compensation that I don't want. So I'll have to pay attention to the code carefully until I get the post right ie step into that warm cosy, feather bed perfect world mentioned after learning a few things & probably bumping a few things. Peter

Cutter comp is normally something you can turn off, look through the Postprocessor setup, G43 will always be there, in all posts unless it is removed, even if you don't use it, you would not need to be remove it as it will only work with the tool you are using and would have no effect on how you are doing your tool Zero setup

Yes, that G53 Z move line should not have been used in that position like that. looks like you need some postprocessor work

The G0Z. move at the top of the program is normal when you don't use an ATC 25mm though is rather low 75mm would be a safer place to have it, at the beginning and the last Z move in your program, then you won't bump into any thing

[peteeng]

Evening all - Well the BOB issue isn't a BOB issue. This happened last time I did this and I ordered a BOB and then found out it was the control voltage. So that spare BOB is going into Matts Scoot and I have another coming as a "new" spare. So today I went through all the voltages and enables/disables etc and started reading the driver manual. Its the same DM452 driver I've used on a few machines. But ah its now different!! it can run on 24V or 5V control voltage and the factory setting is 24V!! a switch on the side of the driver flicked and all things sprung to life. The usual "ITS ALIVE" happy dance was done and now we can move onto marrying the electrons to the metal...

https://www.facebook.com/ScootCNC/vi...37324284422329

[peteeng]

Hi All - Been mucking around with Matts motors and seeing how fast they can run by themselves no load. The Nema23 on 48V can get to 3000rpm. The Z axis motor on 24V gets to 1000rpm. I may run some 48V into the Z to see how it goes... Probably no torque at these speeds but they spin well. I set the acceleration to 200mm/sec2 but that's too much and they stall at some point in their ramp up. At 125mm/sec2 (125/9810= 0.013g) they ramp up and down quite happily.... Peter

[peteeng]

Good Day All - I have been running dummy programs and getting an understanding of some of the post processors in Fusion360. I've sorted the height settings and have been looking for a suitable learners project, model, NC post - cut. This came up today in the form of a bracket for the umbilical cable we shall use on Matts Scoot. He's a scuba diver so he likes the look of the umbilical... So I modelled and ran the NC, a bit scary but it worked!! So I'm along the learning curve somewhat. A question for the F360 CAM gurus. I often clamp the RHS cut the LHS reclamp LHS cut RHS for profiles. But in F360 I can't seem to figure how to path this. Do I have to make dummy geometry? If I use edges or sketch's the tool goes down the middle and I can't find an instruction for inside or outside of the line?? In a wireframe modeler this is easy. Seems I have to make a dummy LHS and RHS so F360 can figure it out... Hmmm Peter

[pippin88]

Hi Pippin - It is as you say outside of the programmed move and UCCNC has a set safe Z ht in its config settings. My Z zero moves around depending on the thickness of the job and the thickness of its waste board. If you use a "high" safe Z it can lift the axis to its mechanical end creating the need for a Z reset. As I don't currently have limit switches on my machines. It can also lift OK but then travel in a straight line to 0,0. If there is a high clamp it may crash into it. Once you crash a couple of times and figure out the best strategy for you it's no big deal unless your brain is not switched on at the time. Which does occur occasionally I'm sure F360 will have little foibles as well. Peter

That might be your answer.

Home switches make life much much easier.
But you can potter on without them. You should always home with you Z near the top of travel. Then have soft limits set so it won't go higher than this.
You should be homing Z (setting machine coordinates / G53) and then touching off Z (setting work coordinates/ G54)

Go-to zero script (pesudocode)
G53 G0 Z0 (go to z zero in machine coordinates, which is full up)
G54 G0 X0Y0 (go to xy zero in work coordinates)

[peteeng]

Hi Pippin - Haven't found the g code for "switch brain-on" yet... The posts have G53 and G54's in them so will work thru your suggestion... I have settled on using the UCCNC stepcraft post. I only have to add a Z (up to clearance ht) in the front and it all works well. Now I have to figure out how to modify the post so its my post. In Fusion I copy the uccnc post to the "my post" folder, update code then it can be run as Scoot Post. Muddling with that this week. Trying to get some stuff organized in the shed, material racks needed badly... & I want to mover Scoot to a better position in the shed.. Peter

image is front of code. I add the Z17 so the tool goes from part (0,0,0) to clearance ht as first move.... the second Z17 is set by the post from the speced clearance ht in fusion vs going along the part surface to its first XY point then up to the clearance ht...

[peteeng]

Evening all - especially any post gurus. I'm deconstructing this post and trying to make the first move a clearance height move. Any suggestions would be helpful as I may take a while to figure it out.

Image "first move" is the output of the post. I want the first move to be to the clearance ht not across the part then up.
Scoot Post No1 is the post that produced this code

Peter

[mactec54]

Evening all - especially any post gurus. I'm deconstructing this post and trying to make the first move a clearance height move. Any suggestions would be helpful as I may take a while to figure it out.

Image "first move" is the output of the post. I want the first move to be to the clearance ht not across the part then up.
Scoot Post No1 is the post that produced this code

Peter

Your Z move is already at G53G0Z0 at the top of the start of the program, if you have homed your machine, so it is fine as posted the Z axis should be up which it is, then the X Y can move then the Z axis can come down to the G1Z17F___. this can be a rapid G0 move, or a G1 Feed move so you don't have to change it from what it is