Hello all, New here, new to CNC. I am running a Workbee 1510. In the OB browser-based CAM, when I create a toolpath, it appears as if the bit's diameter cuts into my part, making it too small. I select an outside cut, and the center of the tool is close to the line, the edge of the bit is inside of the outside of my part's line. Before I noticed this phenomena, I tried to calibrate. I was off by a bit, and now I have it closer, more like 2.010" for a 2" square. At first it was 2.020", and a 40" part came to 40.4", as expected with that amount of difference. That is a whole separate thread, because when I change microsteps even by the smallest increment it seemed to swing my final piece about 0.020" in either direction. Also, I notice that most of the time when I try to move a drawing in the CAM, it creates a line that goes way off to the edge of the screen, as shown in an attached photo with a 2 circle. Is this just a bug? Also also, when this happens, I can't just delete a dxf off of the CAM area...I have to create a new workspace. But what if I upload multiple, how would I delete just one? Can you even do that? But, in this thread I'm really mostly concerned about the toolpath. I ensured that my bit size matches what is listed in the toolpath for the drawing. 6.35mm for my 1/4" bit. is there some setting I need to change to ensure that the bit goes to the edge of my part and not I attached a 2nd photo that shows this. Am I just expecting something that isn't going to happen? I've used MasterCAM in class some, and the toolpaths always seemed to line up to the edges that a bit was going to work on. Is this just a visual bug, maybe? Please have mercy. This machine seems like it will be wonderful when I get it dialed in. Thanks for your help in advance! - Alex
The viewer uses a Perspective camera so that undercut you see is just because the cut is deeper in Z on the view so the camera draws is smaller to maintain perspective view. Easily seen with more passes. It will 100% be the correct size (off set by half tool diameter) The incorrect cut sizes are more likely mechanical deflection. Take less aggresive cuts (shallower DOC or lower feedrate) The circles with the odd lines are likely just a DXF versioning issue. Please use DXF R14 Polyline format
Are you absolutely sure your bit size is 6.35 mm? I have yet to meet one that is. If you found a source please tell us. But seriously, measure every cutter you have and input those dimensions as your cutter diameter. I have a freud "1/4 inch" two flute straight cutter I love for wood and HDPE because I get nice clean cuts with no tear-out in wood, but the real diameter of my cutter is 6.11mm. So if I input 6.35 mm, my part would be off by almost 1/2 mm. I actually am a fan of cutters that come in smaller than spec. That way, I can cut a 1/4 inch slot and still have a little material left over for a finishing cut using the same cutter. If you do not have a digital caliper, these are indispensable in my opinion (which seems to be highly valued by only me). There are cheaper ones, but these two are all I can attest to since I have both and I have had good luck with them. https://www.amazon.com/gp/product/B000GSLKIW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 https://www.amazon.com/gp/product/B001AQEZ2W/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Yes, cutter measurement is critical. Not sure about the manufacturing process but taking a 0.25" diameter piece of HSS for example, it is impossible to have sharp edges at the business end without removing some of the material hence slightly smaller diameter of the cuuting edges.Not sure about carbide tipped cutters though.
when calibrating you should do it over the longest distance possible. ie not over 2" but instead over 40" . and you don't need to change the calibration by some 'guessed' amount when it can be calculated to many decimal places. OBControl has a calibrator built in or you can follow the instructions . (which may lead to understanding the process better which will lead to doing it better )
