Cutting 1.6mm Aluminium sheet

New Home Forum Mostly Printed CNC – MPCNC Advice – MPCNC Cutting 1.6mm Aluminium sheet

This topic contains 48 replies, has 6 voices, and was last updated by  Manuel B. 2 months ago.

Viewing 19 posts - 31 through 49 (of 49 total)
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  • #43697

    Kevin Lopez
    Participant

    Can’t print loc line, just get it off ebay for the el cheapo price of $10. So worth it. Injected molded acetal, their tolerances are really tight. They literally snap on.

    If you are big thin plates then slotting is generally what you will do. I like to reserve trochoidal for thicker parts. Otherwise it just takes waaay too long, like your 18 hour gcode lol. Nothin more fun than doing an all nighter with a vacuum right??

    1 user thanked author for this post.
    #43698

    Barry
    Participant

    I opened the picture in estlcam, it will open a new wizard for this.

    1 user thanked author for this post.
    #43735

    Manuel B.
    Participant

    Hi,

    I found the problem was in my 3mm double flute bit which got dull after 5 hours of cutting??!! Perhaps I pushed too much when searching for settings but definitely will search for cheaper bits around. Also aluminum could be t4 and will ask next time for T6.

    I tried with 4mm double flute and is cutting well using repetier. Only Ramps crashed during milling after 1 and half hours.

    Currently I tried to set up ESTLCAM controll. All went well and I prefer it against Repetier but trochoidal movements xy axis are really odd, slow, rough and not fluid.

    Should I start a new post? Here the link to video :

    Currently I set 3200 step/rev on all axis but tried also all other stepping settings.

    I set max feedrate to 50mm/s and used Ryan`s settings found in the forum.

    Linear milling is ok and manual movements as well.

     

    What could be the issue as the XY movements during trochoidal milling are extremely slow, rough and not fluid?

    Here video for better understanding :

    https://youtu.be/wz5Of0sqQqQ

     

    I am trying to mill a frame few days already and learning hard way/having plenty issues when I depart in few days and I am in the rush.

    #43775

    Manuel B.
    Participant

    During tests today trying to set up ESTLCAM controller on my MPCNC with RAMPS 1.4 , drv8825 :

    • settings drv8825 1/32 6400/rev estlcam won`t allow it
    • settings drv8825 1/16  3200/rev estlcam accepts but max trochoidal feed rate is 6 mm/s
    • settings drv8825 1/8  1600/rev estlcam accepts but max trochoidal feed rate is 6 mm/s
    • linear milling/ trochoidal off – feed rate is high and no problems on that side

    Tested with 32bit PC and 64bit PC, same, max trochoidal feed rate is 6mm/s with estl cam.  Also tryed different settings in estlcam cnc controller but no changes at all.

    Returned back to Repetier and found with 1/32 steps the max trochoidal feed rate is 10-12 mm/s. Above the 10-12 mm/s starts to jitter a little. When I set 30 or 50 mm/s there is no visible increase in speed, only more jitter.

    I can use repetier only for trochoidal milling with similar settings as Barry mentioned – lower feed rate 10mm/s and higher trochoidal step as 9%.

    With ESTLCAM as controller which I prefer, can do only slotting.

    So, either this machine cant go above the mentioned feed rate for trochoidal milling, the software cant handle it or I did something wrong. If you have any advises, what can be checked, dont hesitate to suggest as I dont know where else the problem resides.  It is originally build as per ryan tutorial (GT2, pitch2mm   , pulleys 16T, steppers Nema17 in parallel with current around 1A on drv8825). The steppers are cold, drv8825 heatsink has around 50-60 degrees C during ops. Loaded MArlin RC7 with additional LCD display library and laser add on on AUX2.

    Additionally I measured the straight movements XY axis and feed rates can be easily acchieved up to 50 mm/s and they also correspond to actuall speed.

    #43776

    Jeffeb3
    Participant

    I don’t use EstlCAM’s firmware. Are you sure you have the steps/mm set right? Why are you saying steps/rev?

    Can you just try to move the bit by 10mm in software and see if it moved 10mm in real life?

    Why did you switch from Marlin?

    #43777

    Manuel B.
    Participant

    Hi Jeff,

    I use estlcam as cam software to generate gcode. It has a possibility to control mpcnc and is versatile with probing etc.

    Which software you use?

    When in 1/32 mode per instance it takes 6400 microsteps for one revolution of stepper which is 32mm with gt2 pulley og 16teeth . One step is 0.005 mm.

    The problem is trochoidal milling speed. Not slotting and linear movements.

     

    #43778

    Jeffeb3
    Participant

    Most people here use Marlin (I use grbl, but there’s not much help here for that). I use EstlCAM for CAM, it’s awesome.

    Referring to things in steps per rev is just confusing to me since I am used to the Marlin setting of steps/mm. So I would call that 200 steps/mm. Maybe I’m the only one that is getting confused.

    I was asking “Why use the EstlCAM firmware, instead of Marlin?” EstlCAM firmware is fine, but there are “proven” techniques that work here, including trochoidal milling in Marlin.

    #43780

    Ryan
    Keymaster

    I agree you should stick with marlin, proven and very easy to diagnose.

    You have to set steps per revolution as well as distance per revolution, if you want to stick with estlcam control, from there you also need to tune the motion and acceleration settings. If there is a specific feature you think marlin doesn’t have I will look into it, but as far as I know we have everything but estlcam’s built in surface mapping, which I don’t actually think works with the mega anyway.

    #43821

    Manuel B.
    Participant

    Hi Ryan,

    I set up all settings, searched in forums and applied same settings as others. Each time I changed the jumpers I changed the settings in EstlCam, reprogramm, etc. Seems the max feedrate for troch mill is allways 6mm/s which is too slow. When it comes to regular movements the feed rates are high and all ok.

    Back to Marlin.

    • Using Marlin and repetier found max trochoidal feed rate is app 10-12 mm/s. I was wondering as some people reported higher feed rates for trochoidal milling weather they really acchived them or something wrong with my MPCNC. I can set 30mm/s in estlcam and controlling with repetier the speed visually doesn`t change or increase compared to 12 mm/s.
    • Which software for controlling mpcnc you use? Repetier, Fusion, others?

    I liked in Estlcam few features as zeroing, continue the job from where you left, movements, probe, surface scan but the last I didn test. Same could be probably acchieved on RAMPS but I dont need it currently. They can come handy with longer jobs. Perhaps same can be done with Repetier but I am not aware of it. 

    Minirambo has atmega 2560 and can perform mesh level calibration which could be similar to surface scan. I was thinking even adding an SPI FRAM to store position and last line of gcode in order to resume job even if loss of power occurs or reset needed due to loss of communications,….maybe in the future.

    #43822

    Manuel B.
    Participant

    Hi Jeff,

    Actually is the same if you use 200 steps per 1mm or 6400 microsteps/revolution, while I rather use the latter since the same is also used when settings ESTLCAM.

    #43832

    Ryan
    Keymaster

    I am not sure I mill from 8-12mm/s (usually 8-10 for tichodial I tend to do 8, I don’t like my machine to shake) If I need things to happen faster I just take deeper cuts, that is the whole point of trichoidal, as deep per pass as possible to use the entire cutting face of your tool.

    The biggest load on the CPU is the Z axis due to it’s higher step count, make sure that rate is set low.

     

    1 user thanked author for this post.
    #43838

    Manuel B.
    Participant

    Hi Ryan,

    Thanks. I succeded to mill finally a small frame with 10mm/s and 9% trocho.step. I had at end again sticking to the bit but most probably the aluminum is 5083 AlMg alloy. Have paused, lowered RPM, added some oil and progressed. Waiting for single flute bits in meantime.

    That make sense! I was not aware of Z steps, that is why you used 1/8 or 1/4 for Z axis for estlcam controller. So, if I revert back for any neccesity to estl controller will lower z steps or swith off Z oscillations.

    Currently I left all axis on 1/32 using repetier all seems fine. No shaking at all, added mid supports , fixed the mpcnc against wall with printed fixtures and is very stable (1,2m x 1,2m x 0,4m). Need to remove excess zipties for belt as red in forum.

    Need also to find only a good way for calibrating or zeroing against workpiece. I think repetier doesn`t hold steppers, so I can mistakenly move the tool or after reset or if want to continue next day would like to accurately return the tool in zero position on the workpiece and continue the job. Thus I find probing very helpfull. Maybe  some code can be added to Marlin(aux 2 pin for probing) and perform probing with script in Repetier?

     

     

    #43839

    Ryan
    Keymaster

    You can use the endstop pins, there are six sets. There is nothing special about a probe pin.

    There is a lot of milling techniques you should get familiar with before you worry about positioning too much. When you do try using fixtures and endstops instead. That is why I spent so much time rewriting marlin for dual endstops. For right now it is best to do it all in a single job using the pause function if you need to change bits or something.

    The current software we use can not use a single probe to compensate the position for twist or not parallel to your axis when positioning your work piece to the table a probe will not help with anything bu the Z axis. The dual endstop feature will allow for much more precise repeatable fixture and positioning jigs to allow for many many things and it is easier than probing and compensating every single piece.

    #43840

    Manuel B.
    Participant

    Thanks Ryan,

    I got some endstops and will install them.

    #43844

    Manuel B.
    Participant

    I still didn`t upload the last firmware. I guess the endstops are enabled and there is no need to pull out jumpers for Z axis as is set in the software to have 4x times less steps ?

    * X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
    */
    #define DEFAULT_AXIS_STEPS_PER_UNIT { 200, 200, 800, 200 } //MPCNC

    I will just add laser output to aux2.

    #43847

    Ryan
    Keymaster

    Depends on what firmware you use. Use the one correct for your equipment.

    Aux2? Have you seen the Leo laser write up, he explains what pin seems to work best and why.

    You seem to be using the guess and check method a lot. you should probably start a thread with your machine specs and size so we can all have an idea of what you are working with. Then maybe a description of what you are trying to do with it. This was a thread about milling aluminum and then you went to estlcam firmware/control, then repetier, and now a laser. I keep scrolling through and trying to read your comments but I am unclear to what you have and what you are actually trying to do with it.

    #43852

    Manuel B.
    Participant

    Ryan,

    Mea culpa if I was jumping a lot from different topics but all is stil connected to milling aluminum. I was trying estl control if perhaps would be better. There are thousants pages in forum, some old, some new. I red a lot of pages and yet I didn`t find latest conclusions since they were maybe in other threads (and there are many which I would like to read). Those advises you give me really help.  I travel a lot and home only one month every once in a while thus trying to do as much as possible in that time.

    I have an MPCNC ,  laser and spindle, extruder waiting. Currently using spindle and trying to cut out something.

    I only mentioned laser since I will add it in firmware if will be used later. Last year have used it on aux 2 and was working, not aware of Leo post, will read it. If I wouldn`t mentioned it I wouldnt know.

    Same with limit switches, remebering few of your posts saying no to them I learned double switches will help with milling and squaring the machine.

    I hope you undertsand for a guy in my position when I have a decent internet connection this forum and advises are a golden mine otherwise would still be reading threads and do nothing.  I guess again 🙂 , you are very busy and I am very gratefull for all your time and advises.

    #43854

    Ryan
    Keymaster

    We are all here to help. I still think it would be best to start a thread of your own with your details and intentions. What board, what drivers, what lead screw, how big is it, what laser, what spindle, what bits?

    Try it my way and then we can help you out more directly instead of in a general way making guesses.

    This is the best place to start.

    Software

    How To

    #43884

    Manuel B.
    Participant

    Thanks Ryan,

    Yesterday went through, downloaded new firmware and all OK now.

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