A CNC is an NC milling, therefore controlled by a computer, which is the dream of all those who want to make beautiful pieces, précises et professionnel de look. In model, the small size of the parts it was possible to equip themselves to stop being ch … to make holes in the right place or to cut pieces in series, and a oktokopter, there are parts in series!
the CNC the least expensive market I know and as I write these lines is the CNC Wood ID-Design. In a stated accuracy of 3/100ème mm, it is sufficient for our needs, because there is no question of machined steel. L’alu, carbon and epoxy are the hardest materials we have to work, This somewhat reduces the stress on the machine. Also, tools we use small diameter.
However the use of a CNC, avant de simplifier l’usinage, implies being able to draw his plans on a software that can then generate files understandable by the milling, ess or by its electronic steering spindle (that is to say, the rotating device that holds the cutter). As it is 2D, that is to say flat cutting, is quite simple, but it is complicated with 3D, varying thicknesses. And I do not speak of 4D and 5D. Here are two extreme examples:
It must then determine the best strategy for cutting: if you first cut off, you may have trouble holding the workpiece. Then add the shifts required to accommodate the diameter of the cutter, will remove material over at least 2 mm. Finally, define what we call the condition of cutting, c’est-à-dire la combinaison type fraise, rpm, depth of the channel and fast forward to the most suitable material.
Then, magic in, unless it has problems. I gleaned on the site http://www.rcpilot-online.com/ a list of problems that may be encountered and their solutions. It is easy to see that the digital cut is an advanced technique which requires specific skills:
Problems and Remedies
The milling inevitably generates problems which we must try to remedy. I have listed the most common:
![File DXF is obtained at a ridiculous level when imported into G code in the operating software of the milling]I : it occurred to format conversion DXF a modified scale. Turn in your drawing program and correct the size of the drawing to get across a G code.
The layout is perfect with a marker but the piece is obtained milled smaller: imprecision is usually a mechanical cause of this disappointment. Check the tightness of all mechanical.
The play is not perfect, its contour is deformed: there was no loss of motor and / or hard spots. Slow ( Strawberry is moving too quickly in the material), revisit the speed of rotation of the cutter which may be insufficient.
How to control the accuracy of the machine: cut in different parts of standard materials. Rectangle, diameter, to the maximum speed supported by the cutter and function of torque available with your engines. Then, Measure with a digital caliper dimensions obtained. The gap between the drawing and the part obtained characterizes the precision cutting of your machine. Ideally if the part is obtained 100% the dimensional drawing, your machine is perfect … Of course it is unrealistic! There will be differences, those instructions will tell you, with all the games running minimized and once all the parameters optimized software, precision milling.
Heat engines: c’est normal, but the operating time may be too long and / or current set too high interface. Take breaks (feature offered on the soft steering) and possibly reduce the flow on the plate interface.
The strawberry haze: the engine speed is inappropriate and / or feed rate too high. Reduce the speed of work and simultaneously the speed of
In the Depron a plastic ball is formed on the cutter: reduce the rpm of the bit and increase the maximum speed of advance.
The wood heats up and eventually catch fire: Strawberry is probably worn or inadequate. But also check that the engine speed is not too high. Slow work.
The drill makes a metallic sound operation: bearings of the drill / grinder probably lack of lubricant. Démontez PERCEUSE et la sous injectez pressione (bombs) a lubricant for high speed rotation.
The fraise deformed if the pendant fraisage: réduisez the vitesse de travail. The cutting of the material is slower than the speed set in advance, this leads to inaccuracies and a risk of rupture of strawberry (exceeding the elastic limit of steel, see file of biplanes MRA January).
The cutter does not return exactly to its point of departure: there was no loss of. Hard spot, Dust in the slides or bearings, or also a feed rate too high. Everything clean and reduce the working speed. Also check the return X = 0 Y = 0 in the corresponding window of the software.
In the bit of metal wear out quickly: steel mill employee is probably insufficient quality. Lubrication has perhaps also failed. Choose a strawberry pro (Otelo or other ) et lubrifiez abondamment pendant le fraisage (oilcan, white spirit, oil ).
The operation during drilling is substantially jerky: drawing file converted into G code certainly has too many duplicates or points, check with CNC simulator duplicates, but back to your drawing and limit the number of sites using a slap over the original design.
Z axis, the descent is perfect but a loss is not observed the rise: engine z axis does not develop enough torque to raise the weight of all. Change the engine to another with high torque or multiplied this axis to mechanically increase the torque, but there will be a loss of speed in the same proportion. There are no limits to the X, Y, Z in the software CNC 3 axes. Drawing parts below the waist and center Max races drawing (0,0) avoids disappointments. How to get the best accuracy: Limit games optimally adjusting the machine, change the bearings or ball bearings used, disposez l’ensemble Y/Z au plus près d’un profilé vertical, this will limit the bending trees Y axis. (the computational method see paragraph)
How to adjust the ratio of rotation speed of the cutter and the progress: through trial and error but also by calculating the speed of attack of the material by the cutter teeth (see MRA 792 page 19).
Choose a drill based on the material: it is imperative to buy strawberries depending on the material it plans to work. Catalogues Pro (Otelo, Lestamps, etc) offer a considerable choice of strawberries, it is spoiled for choice, sure to take a drill with a tail with a diameter related to the gate pin of the drill / grinder!
Travelling on an axis is reversed: The suffit, either reverse the son on the respective engine (see section on wiring damencnc.nl), or simply the soft steering, go into the setup menu and reverse the motor direction. How to fix a material on the table for milling then: a sheet of Depron glued to the double face can serve as a disposable spacer, cutting the material is also pasted to the double-sided tape for carpeting. It is necessary to make a device screwed ( and U profiles) for hard materials such as metals or composites.
I want to mill a piece longer than the race “X” machine: proceed in two. It moves the material using a mason’s rule to maintain alignment, then resumed the milling. There is necessarily a loss of accuracy (for the new positioning), but except in the case of the embodiment of a mold, This solution is feasible.
I want to get a bigger fine tuning: passez a fashion ½, ¼ or more step on the plate interface if it offers this option. But this requires attention when greater computing power.
I want to get a higher working speed: alimentez and 24 V (jusqu’à 40 v sur l’interface View CNC ) your engines and eventually go under DOS Turbo CNC as control software.