Engraving Stainless Steel to Engrave Stainless
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Engraving Stainless Steel To engrave stainless steel, we use a number of techniques to overcome the inherent problems of machining a hard surface. In 99% of cases, the one item that will cause the most difficulty is the cutter. To engrave stainless, the cutter must be perfect. The diagram below will assist you in judging the cutter. Cutters for stainless steel are made of a very fine grade Tungsten Carbide. This allows them to wear instead of chip. Any accidental impact or overheating may cause it to fracture, so extreme care must be taken to preserve the cutting edge. In addition the cutter is ground to a 60-degree angle, wider angle than the 45-degree usually used in engraving. This aids the tip strength and gives more life from a cutter. Cutters that are no longer sharp can be reground many times. This diagram shows the cutter viewed from both sides. As you can see the cutter rises to a point and has a flat surface on the top called the tip. The point is the part that does the cutting. This point being offset from the cutter centre line creates the width of cut. Any fragmentation of this tip or a slight rounding off will cause burring in the material. Look at the tip of the cutter through the magnifier. If there is a lighter colour on the cutting edge there is fragmentation of the carbide and the cutter needs resharpening. This is the cutting edge. The light marking is indicated. This may be accompanied by a slight rounding off of the cutting tip. If either is seen the cutter must be reground. Protecting your cutter is quite straightforward but is very important. Never drop the cutter. When approaching the material, do so at rate that will allow the cutter to cut, rather than force the material. Do not attempt to remove too much material in one go. Use good quality lubricant /cutting fluid. The other main problem with cutting stainless is heat. This can be caused by excess depth of cut. Or excess speeds. For paint filling purposes the depth of cut is usually between 0.3 and 0.5mm. This can be achieved in two - three passes, providing the material is flat and is mounted flat to the cutter. More usually with pressed steel plates, the material has a curvature at the edge which causes the surface to be bowed. If you try and cut near to correct depth in one part of the plate, the cutter may miss or go very deep at other parts of the plate. This over depth may take the edge of the cutter and render it useless until it has been reground. To protect against this, add additional pass depths. To protect against overheating through speed, start slowly and build up. If at any point the material starts to "ring", that is vibrate badly, or the engraving motor starts to "bog down", the speeds need to be reduced. Below is a guide to setting up a job through Engravelab. 1) Specify the Plate Size from the layout screen. This should be the same as the piece of material to be engraved. 2) Place the text on the screen using the text tools and arrange the text using the alignment and move tools to create a suitable layout. 3) Place a series of tool paths in the lettering. Toolpaths can be used to infill an area of text. They are also used to add depth to an item by choosing an online path. When the toolpaths are applied, set the final depth in the depth box and use the three dots next to the depth line to set number of passes. Overlap clears the base of the cut. The bigger the percentage the flatter the base but the job will take longer. If the toolpath is deleted and recreated at any time, the number of passes will be recalculated using the tool library information and the final depth. 4) To set the speed, use the Tool Options in the Engrave Menu. To set the parameters, first select the Std speed tool from the side. Then set the XY Cut Velocity. The figure shown here is 7.00mm / second. This value will be applied when the XY speed on the handset is at 100%. The plunge velocity is set to 3.00mm / second. This is the speed at which the tool enters the material. The other item here that may be adjusted is the tool lift. This is the height that the cutter lifts between characters. The current setting is 4.00mm. The other speed, which needs to be considered, is the rotation of the cutter. At full speed the cutter rotates at approximately 20000 rpm. With the speed through the material being so slow, this is a bit fast and can generate its own heat problems. Slow this down by reducing the RPM control on the box. There is no hard and fast rule for this, but listen to the motor as it has limited power at lower revs. If the cutter sounds like its being slowed down significantly when entering the material, the speed may be too slow. The general rule when engraving a harder surface is to start slowly and build up. The multi-passes will protect the cutter from any irregularities in the surface and the speed will keep the heat down Once the ok button is clicked, a fill should now appear on your text. If it does not there are 2 things to check. a. Go to view and make sure Show tool paths has a tick next to it. b. Re-do the toolpath with a smaller cutter as the shape or text may be too small for the cutter to fit in When the fill is on highlight the job, go to Engrave and Engraving Defaults. Put a tick in the Output tool path, if there is one there already take it out and re apply the tick. A tool path options box comes up. Copy the figure above for the correct setting. Click ok, now select save default and click ok. Press F3 to select all objects and select your Output tool. This now brings up a preview of the engrave you’re going to do with the fill. Before sending it to the machine, click on the eye icon twice, the first click turns your engrave all black the 2nd click opens a prompt box. In the prompt box take out the tick from Also cut contour paths and click ok. Now the job is ready to be sent to your machine In the prompt box take out the tick from Also cut contour paths and click ok. Now the job is ready to be sent to your machine .