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  • lingib commented on lingib's instructable CoreXY CNC Plotter4 days ago
    CoreXY CNC Plotter

    You're welcome ... good luck with your project :)

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  • lingib commented on lingib's instructable CoreXY CNC Plotter5 days ago
    CoreXY CNC Plotter

    Mounting the MotorsDrill four x 3mm mounting holes, and one spindle clearance hole, for each NEMA17 stepping motor as shown in photos 2 & 3.The outside 3mm holes are 25mm from each edge of the base. This distance ensures the the motors avoid the wooden support and the aluminium side rails.Since the mounting holes are 31mm apart the spindles are 40.5mm from the side rails.The distance from the wooden supports was set at 25mm. This distance means the nuts don't hit the timber.Mounting the fixed pulleysDrill two 4mm holes for the fixed pulleys.These holes are located 25mm from the opposite end to the motors and 40.5mm from the side rails. This distance ensures that the pulleys avoid the wooden support. It also ensures that the timing-belts are parallel with the side rails.The holes for...

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    Mounting the MotorsDrill four x 3mm mounting holes, and one spindle clearance hole, for each NEMA17 stepping motor as shown in photos 2 & 3.The outside 3mm holes are 25mm from each edge of the base. This distance ensures the the motors avoid the wooden support and the aluminium side rails.Since the mounting holes are 31mm apart the spindles are 40.5mm from the side rails.The distance from the wooden supports was set at 25mm. This distance means the nuts don't hit the timber.Mounting the fixed pulleysDrill two 4mm holes for the fixed pulleys.These holes are located 25mm from the opposite end to the motors and 40.5mm from the side rails. This distance ensures that the pulleys avoid the wooden support. It also ensures that the timing-belts are parallel with the side rails.The holes for the fixed pulleys must be 40.5mm from the side rails if the timing belts are to be parallel.The distance from the wooden supports was set at 25mm. This distance means the nuts don't hit the timber.Hope this helps :)

    "Mounting the motorsDrill four x 3mm mounting holes, and one spindle clearance hole, for each NEMA17 stepping motor as shown in photos 2 & 3.The outside 3mm holes are 25mm from each edge of the base. This distance ensures the the motors avoid the wooden support and the aluminium side rails."The 3mm motor mounting holes are spaced 31mm apart. This means that each spindle is 40.5mm from the nearest siderail"Mounting the fixed pulleysDrill two 4mm holes for the fixed pulleys.These holes are located 25mm from the opposite end to the motors and 40.5mm from the side rails. This distance ensures that the pulleys avoid the wooden support. It also ensures that the timing-belts are parallel with the side rails."The fixed pulleys must be 40.5mm from the nearest siderail if ...

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    "Mounting the motorsDrill four x 3mm mounting holes, and one spindle clearance hole, for each NEMA17 stepping motor as shown in photos 2 & 3.The outside 3mm holes are 25mm from each edge of the base. This distance ensures the the motors avoid the wooden support and the aluminium side rails."The 3mm motor mounting holes are spaced 31mm apart. This means that each spindle is 40.5mm from the nearest siderail"Mounting the fixed pulleysDrill two 4mm holes for the fixed pulleys.These holes are located 25mm from the opposite end to the motors and 40.5mm from the side rails. This distance ensures that the pulleys avoid the wooden support. It also ensures that the timing-belts are parallel with the side rails."The fixed pulleys must be 40.5mm from the nearest siderail if the timing belts are to be parallel.The distances from the wooden end supports is arbitary ... so long as the motors and nuts don't touch the wood.Hope this helps :)

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 week ago
    CoreXY CNC Plotter

    Thank you for your comment :)Download the file CoreXY_parts_list.txt attached to Step 3. This file lists the website from which all items were obtained and the product descriptions. Cut and paste each of the descriptions into the website's search-bar and select the supplier who offers the best deal.Two thin aluminium 'L-sections' bolted back-to-back should work If you can't find aluminium 'tee-sections'. Most hardware stores contain a range of aluminium extrusions.

    Thank you for your comment :)Step 3 contains a file 'CoreXY_parts_list.txt ' which lists of all items and their product descriptions. The website from which these items were obtained is also listed.Cut and paste each of the descriptions into search-bar of that website and select the supplier who offers the best deal. Two thin aluminium 'L-sections' bolted back to back should work If you can't find aluminium 'tee-sections'.

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 week ago
    CoreXY CNC Plotter

    The instructable definitely contains a video. Try closing and reopening your browser as weird things can happen.

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  • lingib commented on lingib's instructable CoreXY CNC Plotter2 weeks ago
    CoreXY CNC Plotter

    CoreXY motion occurs due to differential action:- rotating motor 1 counter-clockwise by hand will cause the plotter to move UPWARDS to the right at an angle of 45 degrees.- rotating motor 2 counter-clockwise by hand will cause the plotter to move DOWNWARDS to the right at an angle of 45 degrees.- when both motors rotate counter-clockwise the up and down movements CANCEL and the plotter moves horizontally to the right.When plotting angle lines one of the motors runs slower than the other allowing for angles other than 45 degrees.The video attached to this instructable shows the plotter in operation.

    CoreXY plotters differ from conventional plotters in that BOTH motors rotate when moving along the X and Y axis. An excellent explanation may be found at http://corexy.com/theory.html. (See instructable steps 4, 5)CoreXY motion occurs due to differential action. Try this:- rotate motor 1 counter-clockwise by hand ... the plotter should move to the right and up.- rotate motor 2 counter-clockwise by hand ... the plotter should move to the right and down.- now rotate both motors counter-clockwise by hand ... the plotter should only move to the right.If this works then your plotter belts are correctly threaded.I get the impression that you may have substituted my code for GRBL in which case you will have to configure GRBL 0.9i (or later) for coreXY. I have not tried this so am unable to hel...

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    CoreXY plotters differ from conventional plotters in that BOTH motors rotate when moving along the X and Y axis. An excellent explanation may be found at http://corexy.com/theory.html. (See instructable steps 4, 5)CoreXY motion occurs due to differential action. Try this:- rotate motor 1 counter-clockwise by hand ... the plotter should move to the right and up.- rotate motor 2 counter-clockwise by hand ... the plotter should move to the right and down.- now rotate both motors counter-clockwise by hand ... the plotter should only move to the right.If this works then your plotter belts are correctly threaded.I get the impression that you may have substituted my code for GRBL in which case you will have to configure GRBL 0.9i (or later) for coreXY. I have not tried this so am unable to help.You also appear to have substituted the stepper drivers. Providing your substitute board(s) are Big EasyDriver compatible this shouldn't be a problem.

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  • lingib commented on lingib's instructable CNC Pen Lift3 weeks ago
    CNC Pen Lift

    Now there's a thought ... a house painting robot ;)

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  • lingib commented on lingib's instructable CoreXY CNC Plotter4 weeks ago
    CoreXY CNC Plotter

    16 gauge aluminium should be fine. I only used 18 gauge aluminium because it was available.

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  • lingib's instructable CNC Pen Lift's weekly stats: 4 weeks ago
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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each of these four pins are set then SIMULTANEOUSLY applied to the arduino output port.You may have to remap the "direction" and step "pins" to match your motor shield. These p...

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    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each of these four pins are set then SIMULTANEOUSLY applied to the arduino output port.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are defined in the arduino header.

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that of the pins to your motor shield are incorrectly mapped or you have your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each of these four pins are set then SIMULTANEOUSLY applied to the arduino output port.You may have to remap the "direction" and step "pins" to match your motor shield....

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    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that of the pins to your motor shield are incorrectly mapped or you have your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each of these four pins are set then SIMULTANEOUSLY applied to the arduino output port.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are defined in the arduino header.

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that some of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic level for each direction pin is set then both motors are SIMULTANEOUSLY stepped.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are define...

    see more »

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that some of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic level for each direction pin is set then both motors are SIMULTANEOUSLY stepped.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are defined in the arduino header.

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that some of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each direction pin is set then both motors are SIMULTANEOUSLY stepped.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are defin...

    see more »

    On re-reading your question I see some potential issues:1 - my plotter does not use a motor shield.2 - my software is self-contained ... 3rd party libraries are not required.It would appear that some of the pins to your motor shield are incorrectly mapped or your motor connections are swapped as HORIZONTAL motion requires both motors to turn in the same direction and VERTICAL motion requires that both motors rotate in opposite directions.The logic I have used when stepping the motors assumes that each motor controller has a "direction" pin and a "step" pin. The logic levels for each direction pin is set then both motors are SIMULTANEOUSLY stepped.You may have to remap the "direction" and step "pins" to match your motor shield. These pins are defined in the arduino header.

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    All idler pulleys have a bore size of 4mm.All stepper pulleys have a bore size of 5mm.

    Is your plotter a CoreXY Plotter ... I ask this because you mention items not in this article such as GRBL and Universal Gcode Sender?The good news ... your motors appear to be working correctly. Horizontal movement occurs when BOTH motors rotate in the same direction. Vertical movement occurs when BOTH motors rotate in opposite directions.You may try loosening the belts ... the motors can stall and produce a growling noise if the belts are over-tightened.Try talking directly to your arduino using the serial monitor in your arduino IDE. Only move to GRBL and Gcode sender when you have each function on the test menu working.[delete]

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  • lingib commented on lingib's instructable CNC Pen and Wash Portrait1 month ago
    CNC Pen and Wash Portrait

    Your method for "hatching a plot" sounds interesting and would make a great instructable :)So far I've tried wiggly lines and variable-width brushes. Any reference to a "shady" method would be appreciated ;)Thank you for commenting :)

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  • lingib commented on lingib's instructable CNC Pen Lift1 month ago
    CNC Pen Lift

    What analytics ?The inspiration for this pen-lift is outlined in the comment section of https://www.instructables.com/id/CoreXY-CNC-Plotte...Glad you find the tool clip idea useful.

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  • lingib posted an instructable CNC Pen Lift1 month ago
  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    Unable to comment as I don't know your required format ;)The MASLOW is a "beefed up" hanging plotter able to winch bricks and CNC routers with ease. As such it able to cut out plywood shapes. The price reflects the cost of parts.This plotter uses lighter weight materials. Heavier guide rails would be needed to support the router used in the MASLOW.

    You're welcome. Thank you for commenting :)

    Unable to comment as I don't know your required format ;)The MASLOW is a "beefed up" hanging plotter able to winch bricks and CNC routers with ease. As such it is able to cut out plywood shapes. The price reflects the cost of parts.This plotter uses lighter weight materials. Heavier guide rails would be needed to support the router used in the MASLOW.

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    Thanks for the lead :)

    Thank you for your comment :)

    Thanks for your reference ... will check it out :)Regarding pen-lifts I have found them to be a major source of error. The tiniest mechanical error is magnified by the length of the pen. About about to try a new idea ... will publish it if it works.You may be able to help me here ... I'm looking for simple pattern filling algorithms such as TSP (travelling sales person) that will port to the arduino. I have found a few articles but they seem overly complicated. Any references would be appreciated ... I don't care if the algorithm isn't efficient so long as it works.

    Thank you for the reference :)Perhaps I am mistaken but the belt arrangement for your plotter is different.Your plotter appears to use a single belt in an H-Bot configuration for movement along the Y-axis (H-bot does not "wrack" in the vertical direction). X-axis motion appears to be from a motor mounted on the carriage-assembly itself. (This would eliminate the "wracking" I experienced in step 6).

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    :)

    Have no experience with drag knives but your idea seems plausible ...

    Thanks :)

    Thank you for your suggestion :)I opted for my method as the parts were on hand from other projects.

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  • lingib commented on lingib's instructable CNC Hanging Plotter1 month ago
    CNC Hanging Plotter

    I purchased the 30mm shaft extenders from:https://www.aliexpress.com/item/30mm-Lengthen-Shaf...

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  • lingib commented on lingib's instructable CoreXY CNC Plotter1 month ago
    CoreXY CNC Plotter

    Thank you :)

    You're welcome. Thanks for your feedback :}

    You're welcome. Thanks for your feedback :)

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  • lingib's instructable Make Your Own CNC Plotter Image's weekly stats: 2 months ago
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  • lingib commented on lingib's instructable Make Your Own CNC Plotter Image2 months ago
    Make Your Own CNC Plotter Image

    Thank you for your comment :)The concept is not new. Years back I recall teleprinter images were often formed using letters of the alphabet. Continuous line algorithms, such as sine waves and TSP (travelling salesman program), are better suited to plotters.Getting the shading right is the difficult part. Try altering the wave amplitude and number of cycles in the drawSinewave() function ...

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter2 months ago
    CNC Dual Arm Plotter

    A great suggestion ...Tension against a vertical surface is possible if you replace the shoulder arms with thick aluminium flat bar and the elbow arms with thin aluminium flat bar as shown in https://www.instructables.com/id/CNC-Drawing-Arm/Tension is then obtained by bending the thin flexible elbow arms slightly downwards until the servo (without the pen) just touches the drawing surface. The weight of the arms would require some form of counter-balance to prevent them dropping.

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  • lingib commented on lingib's instructable CNC Drawing Arm3 months ago
    CNC Drawing Arm

    A minor code update, "CNC_drawing_arm_v3.ino", has been added to "Step 8".Raw Inkscape g-code may now be used should you wish to create your own test patterns.

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  • lingib commented on lingib's instructable CNC Drawing Arm3 months ago
    CNC Drawing Arm

    A code update, "CNC_drawing_arm_v2.ino", has been added to "Step 8".This update improves the stepping algorithm which results in smoother lines.

    Thanks for your comment :)In practice the torque on the shaft has not been an issue ... I just saw it as a disadvantage relative to the dual-arm versions at the time I wrote the article.The main problem are the tiny "wiggles" due to the motor movements being magnified by the 300mm arms. Shorter arms would reduce this effect but would also reduce the plot area.

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  • lingib's instructable CNC Dual Arm Plotter Version 2's weekly stats: 3 months ago
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  • lingib commented on lingib's instructable CNC Drawing Arm3 months ago
    CNC Drawing Arm

    Thank you for your comment :)Depending on what you want to print, a robotic arm may not give you the precision that you require as there is a hidden problem. The precision degrades with distance :(Some calculations using my diagrams:Let A=angle, D=distance, L=arm length=100mm, motor=1.8 degrees per step.cos(A)=(D/2)/L) ................. ....................(1)rearranging we getD= 2*L*cos(A) ........................................(2)Let's now calculate the change of distance (d) for a single step for three different start angles.The required formula becomes:d=2*L*cos(A) - 2*L*cos(A+1.8)d=200(cos(A) - cos(A+1.8)) ................... (3)Substituting for start angles of 20, 40, and 60 degrees we get:20 degrees: d=200(cos(20)-cos(21.8)) = 2.24mm40 degrees: d=4.11mm60 degrees: d=5.48mmThese ...

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    Thank you for your comment :)Depending on what you want to print, a robotic arm may not give you the precision that you require as there is a hidden problem. The precision degrades with distance :(Some calculations using my diagrams:Let A=angle, D=distance, L=arm length=100mm, motor=1.8 degrees per step.cos(A)=(D/2)/L) ................. ....................(1)rearranging we getD= 2*L*cos(A) ........................................(2)Let's now calculate the change of distance (d) for a single step for three different start angles.The required formula becomes:d=2*L*cos(A) - 2*L*cos(A+1.8)d=200(cos(A) - cos(A+1.8)) ................... (3)Substituting for start angles of 20, 40, and 60 degrees we get:20 degrees: d=200(cos(20)-cos(21.8)) = 2.24mm40 degrees: d=4.11mm60 degrees: d=5.48mmThese distances will be smaller when we use 16*microstepping and 4*belt drive but the non-linearity is cause for concern.A cartesian XY system using a GT2 20-tooth pulley and a matching GT2 timing-belt offers better linearity, and higher resolution. With this approach 1 motor revolution of 200 steps moves the timing-belt 20*2=40mm which equates to a CONSTANT distance of 40/200=0.2mm for each motor step. Microstepping would further improve this.

    Thanks for the "RepRap Helios" reference ... the design is interesting.

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  • lingib commented on lingib's instructable How to Cut & Fold Sheet Aluminium3 months ago
    How to Cut & Fold Sheet Aluminium

    Your post was great ... it explains why I had difficulty bending an aluminium sheet some years back. Love your workshop definition :)

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  • lingib commented on lingib's instructable How to Cut & Fold Sheet Aluminium3 months ago
    How to Cut & Fold Sheet Aluminium

    The aluminium sheet used for the demonstration was 18 gauge.The angle was 1.25 inch (32mm) ... as you say you wouldn't want it any smaller.

    The sheet was 18 gauge

    Thank you for this information.I haven't experienced any of the problems that you mention when using 18 gauge aluminium but points taken. I simply make a test bend then make allowances for the remaining bends ...

    Don't make the internal cuts first. If you do the edge will NOT bend cleanly.Bend the edge and make the cuts before folding ... the joint will be perfect.

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter Version 23 months ago
    CNC Dual Arm Plotter Version 2

    I-sections and good joint bearings are definitely required if you want to achieve the theoretical accuracy.A solenoid operated pen lift, or the equivalent, would be better. The servo-horn, while simple, causes the arm to move slightly during the pen-up movement.I have been experimenting with openCV and computer vision ... now there's a possibilty ;)

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter3 months ago
    CNC Dual Arm Plotter

    Thank you for the servo info :)And fine on the cosine formula. It is definitely the way to go for arm ratios other than 1:1. The cosine formula simplifies down to angle=acos(distance/(2*arm-length)) if the arms have a 1:1 ratio.The problem you have with the joints can be eliminated by drilling the joints to 3/16 inches (4.76mm) and inserting a tubular 3/16 inch radio spacer. Cut the spacer length to suit by placing it to the correct depth in an electric drill and holding a hacksaw blade or fine pitch file against the spacer ... works like magic. Now sandwich the spacer between two 3mm washers and a 3mm nut and bolt. The finished result is a low friction joint with no sideways play.

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  • lingib commented on lingib's instructable How to Cut & Fold Sheet Aluminium3 months ago
    How to Cut & Fold Sheet Aluminium

    I found a length of angle in a scrap yard many years ago and made it myself.Just cut two equal lengths and drill two holes for the bolts. I drilled the holes at least 25mm below the top edge so the full length of the bender can be used to form a lip when making radio chassis.The reason for so many slots is to accommodate different width radio chassis. I always bend the two longer sides then bend the shorter sides which means I need two slots.

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter3 months ago
    CNC Dual Arm Plotter

    Thank you for your comment :)I looked at 1:2 shoulder:elbow ratios but opted for equal length arms as the maths was simpler and making "Offset1=Offset2" allows for 360 degrees rotation should that be required.The accuracy of the "dual-arm" plotter configuration can be improved by attaching GT2-20 pulleys to each of the motors and repositioning them sideways. Now fix each of the shoulder arms to a GT2-80 pulley that is free to spin about 6mm bolts located where the motors were originally positioned. GT2-200 timing belts linking each of the pulley pairs creates a 4:1 gear ratio.Replacing the "EasyDriver" with a "Big EasyDriver" set to 16 times microstepping increases the total resolution by a factor of 4(gear)x2(microstepping)=8.The lines shown in t...

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    Thank you for your comment :)I looked at 1:2 shoulder:elbow ratios but opted for equal length arms as the maths was simpler and making "Offset1=Offset2" allows for 360 degrees rotation should that be required.The accuracy of the "dual-arm" plotter configuration can be improved by attaching GT2-20 pulleys to each of the motors and repositioning them sideways. Now fix each of the shoulder arms to a GT2-80 pulley that is free to spin about 6mm bolts located where the motors were originally positioned. GT2-200 timing belts linking each of the pulley pairs creates a 4:1 gear ratio.Replacing the "EasyDriver" with a "Big EasyDriver" set to 16 times microstepping increases the total resolution by a factor of 4(gear)x2(microstepping)=8.The lines shown in the "After" photo in step 11 are now perfectly straight.Would be interested to know what servos you are using?

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter4 months ago
    CNC Dual Arm Plotter

    The lines would still be curved.There is an inherent distortion whenever you convert XY co-ordinates into angle-distance. The maths behind this is explained in step 3.The good news is that this distortion can be masked by introducing addition plotting points as demonstrated in step 11.

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  • lingib commented on lingib's instructable CNC Drum Plotter4 months ago
    CNC Drum Plotter

    Thank you for your comments :)The plotter was built as proof-of-concept. If I were to redesign this plotter I would use stronger motors and add a step-up belt drive to rotate the drum ... this would eliminate the need for a drum tensioner. Other than that your ideas would work ... plus you could make the drum as long as you like.

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter4 months ago
    CNC Dual Arm Plotter

    The code for this plotter has been udated to support lines and arcs. See Step 11 of this instructable for "CNC_dual_arm_plotter_v2.ino"

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter5 months ago
    CNC Dual Arm Plotter

    The "interpreter" commands to which you refer do not appear on the menu as they are only required when plotting the output from Inkscape.The only commands that an Inkscape plotter must recognise are G00 (linear move with the pen up), G01 (linear move with the pen down), G02 (clockwise arc with the pen down), and G03 (counter-clockwise arc with the pen down). All other commands may be safely ignored.For proof-of-concept testing I have converted all G02, and G03 commands to G01 (linear move with pen down). For the purpose of transferring watercolor outlines to paper this is accurate enough as points that are close together approximate a straight line.Code for generating perfect lines and true XY arcs are detailed in my instructable https://www.instructables.com/id/CNC-Drum-Plott...

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    The "interpreter" commands to which you refer do not appear on the menu as they are only required when plotting the output from Inkscape.The only commands that an Inkscape plotter must recognise are G00 (linear move with the pen up), G01 (linear move with the pen down), G02 (clockwise arc with the pen down), and G03 (counter-clockwise arc with the pen down). All other commands may be safely ignored.For proof-of-concept testing I have converted all G02, and G03 commands to G01 (linear move with pen down). For the purpose of transferring watercolor outlines to paper this is accurate enough as points that are close together approximate a straight line.Code for generating perfect lines and true XY arcs are detailed in my instructable https://www.instructables.com/id/CNC-Drum-Plotter/To implement true arcs for this plotter the XY co-ordinates from the above code must be converted into angle-distance co-ordinates before being sent to the move_to() function.Regarding the parts ... the BYJ48 stepper motors that I have used in all of my other projects couldn't withstand the "push" from each other so I searched the internet for the cheapest parts that would be suitable.

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter5 months ago
    CNC Dual Arm Plotter

    The NEMA17 17HS4401 stepper is not compatible with the EasyDriver module as that stepper requires 1.7A but the EasyDriver module only supports currents up to 750mA. The code, however, will work if you locate a substitute board for the EasyDriver as both motors are 1.8 degrees per step.

    The wobble goes if you substitute a short pencil for the tall ink pen which has a lot of inertia.

    It may work vertically if you were to attach a strong (lightweight) magnet to one of the arms and use a magnetic whiteboard ... just a thought.

    Stronger motors, or some method of counter-balancing, would be needed for vertical plotting. The existing motors lift the mechanism but don't prevent the mechanism dropping (due to gravity) past the target location when the pen is being lowered.

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  • lingib commented on lingib's instructable CNC Dual Arm Plotter5 months ago
  • lingib commented on lingib's instructable CNC Graphics Tablet5 months ago
    CNC Graphics Tablet

    Step 6 contains the source code for this project

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