19 Replies Latest reply on Jul 9, 2016 6:51 AM by D_Hersey

    Basic CNC


      Sorry to ask this question, but I have a new CNC MACHINE but I have not a clue how it works so frightened to try and use it without it disintegrating into loads of bits. So I live in Hereford in the UK and would like help from someone who would be prepared to show me. A good supply of brews a good dinner and if one day is not enough then you can stay.

      I would be grateful for any help.


      many thanks



        • Re: Basic CNC
          Andy Clark (Workshopshed)

          Hi Raymond,

          when I was being trained on CNC milling we used foam to test our programmes, that allows you to see the tool path and note if you've run the tool into the work piece by mistake. Oasis foam from a florist supplier should work well. You might want to post onto a model engineering forum as there could be someone who could help there.



          The home of Model Engineer and Model Engineers' Workshop Magazines


          Home | Model Engineering Clearing House


          Good luck with your search.



          • Re: Basic CNC

            The worst thing with a CNC mill is to crash the cutter into the table.  You can use a piece of wooden dowel rod to simulate an end mill and 'cut air' the first time you run your program.  You didn't say your device was a lathe or a grinder or a wire EDM, lotsa stuff can be CNC.


            This is not a trivial topic.  I live in the states and one of the local JuCos (Harper) is putting a program together.  I don't know the hierarchical divisions of secondary education where MK got his certs.  But however you do it over there I would try to get trained in school.  Failing that, manufacturers of CNC equipment do a lot of educating as well.


            Are you acquainted with conventional machining?

            1 of 1 people found this helpful
            • Re: Basic CNC

              IIRC Chicago is the machining capital of the planet, because O'Hare, as an aside.  Around here they use machinable wax as a practice material.  They superglue parts together when they want to make a part so complex that it would be impractical to mill, then sandcast it.  It is a mix of paraffin and polypropylene, AFIK.  They typically dye it blue.  You can melt and re-cast it, but no one ever seems to.




              Does your machine have a toolchanger? 

              • Re: Basic CNC

                There is a process to cast foam as well, it is called 'lost foam.'  They spray the foam with a ceramic coating before casting it.  That is how Saturn auto engines are fabbed.  Now that I recall.

                • Re: Basic CNC

                  Hello Raymond,


                  To be honest I am attracted by your offer, but unfortunately I can't stay outside here where I temporary live for at least until the next end of september. But I am reasonably sure that I can help you by remote avoiding you destroy your machine and giving good results. It is at least the worth to try. I think that we can organise a sort of step by step helpful discussions. I can transform them in articles and you can follow me experimenting. Take in account that my personal experience with CNC machines is focused on a self-teaching path so there are lot of errors I can avoid. And probably give you good suggestions on hardware settings and the principles.


                  When I started (my very first step was to make one CNC from scratch) I tried to follow and interact with a lot of specialised CNC forums but frankly I have just found a great confusion. If the idea sounds good, you can contact me privately just to discuss the boring parts related to the steps then we can start. Making public a path to reach results I think this may be also useful for a lot of other users.



                  • Re: Basic CNC

                    Like Enrico, I too could help you by remote. I have built a CNC from scratch as well, I also program G-code (CNC language) and run a CNC (for woodworking) almost every day. If I can do anything to help, PM me. Between Enrico and I as well as any other help, I'm sure you will get through this!!



                    • Re: Basic CNC

                      Can you post a picture and spec of your machine.

                      If you want some trial material to cut that's a step up from Oasis flower stuff then buy some ModelBoard- here's a note I sent to someone a while ago:


                      It was made from this stuff (probably M540):




                      but only because that was convenient for prototyping - for production it should be molded and there are a host of suitable plastics you might use - you would need to get advice from the tool designer/plastic molder.


                      You can make functional things from the right grade of modelboard - one day I mean to make some loudspeaker cabinets from it.



                      1 of 1 people found this helpful
                        • Re: Basic CNC

                          Hi, just looked at the site url that you sent me. I will look at the options that are sold.

                          I will look now and see if I can find the machine I have. Due to illness I have not been able to use, and

                          its been on my bench for 2 years.

                          regards RayMort

                          • Re: Basic CNC

                            I don't have a pic at the moment but here is the spec.


                            1 xRefurbished A3 3 Axis Hybrid BALLSCREW Desktop CNC Machine Router Engraving KIT Router



                            Ballscrew Machine Assembled

                            A3 size Machining Area - 500mm x 300mm, Z Axis 155mm

                            Footprint: 950mm x 750mm



                            Accuracy/Repeatability: 0.01mm



                            Translation: Ballscrew

                            Linear: Hiwin profile rails and carriages



                            MDL NOTE: CUSTOMER TO SUPPLY: Desktop PC, Monitor, Keyboard and Mouse



                            Machine Control Software - Mach3 Full License

                            Design Software - VCarve Pro 7



                            Electronic Jogging Handwheel



                            Controller: 3 Axis Controller and x3 NEMA23 3.1Nm Stepper Motors (X, Y and Z)



                            Proximity Home Switch (X, Y and Z) and additional external emergency stop



                            Kress Spindle 1050FME, Kress Motor Mount, Brushed dust hood with connection for 38/63mm out

                            3 x Kress Collets: 3mm, 6mm and 8mm



                            Sample Milling Cutters, 4 x T-Nuts, Grease



                            Single phase - standard socket 240V

                            One socket required - extension lead supplied



                            Shipping price added during checkout includes 2-3 hours installation and initial training followed by free email and telephone support20%£1,185.00
                            1 xVectric VCarve Pro 7 and Mach3 Bundle

                            Code: [VCARVEMACH3]

                            1 xDelivery, Assembly + Training - UK20%£280.00
                            1 xNew for 2013




                            USB (V2.x) from PC/Laptop running Windows XP, Vista or Windows 7 (32 bit or 64bit)

                            motor driver connector pin-out is compatible with 10 pin open source interface (Linistepper, PICStep)

                            controller works with most step/dir stepper and servo motor drivers available on the market

                            buffered IO for maximum performance

                            advanced interpolation algorithms

                            start, stop, pause and resume execution of program on your machine

                            standard RS274/NGC G-code (EMC2 compatible)

                            advanced G-codes - G40, G41, G42 (Cutter Radius Compensation) supported

                            advanced G-codes - G43, G49 (Tool Length Offsets) supported

                            advanced G-codes - G54, G59.3 (Coordinate System Origins) supported

                            tested with SolidCAM, MasterCAM, ArtCAM, Vectric, CamBam, MeshCAM ... generated G-code

                            Profili 4-axes and 3-axes G-code supported

                            import toolpath from DXF files

                            import toolpath from PLT/HPGL files

                            import toolpath from image files

                            import toolpath from NC-Drill (Excellon) files

                            import toolpath from Gerber (RS-274X) files

                            toolpath simulation

                            automatic homing procedure

                            advanced toolchange procedures

                            automatic tool length measuring

                            export toolpath to G-code

                            export toolpath to DXF

                            SDK (software developers kit) is available

                            works on MacOS X (Snow Leopard 10.6.3) with virtual machine emulating Windows XP SP39 axes USB CNC controller Mk2:

                            100 kHz maximum step frequency

                            7 digital outputs

                            12 us minimum pulse width

                            manual jog inputs for all axes

                            limit inputs for all axes

                            5 general inputs

                            8 control inputs for pendant or similar device

                            SD card support for running g-code without computer

                            control external devices with I2C protocol

                          • Re: Basic CNC

                            G codes are 'go codes,' they result in movement, M codes are 'modal codes,' like turn on/off the coolant,  It is neat that you have cutter radius and cutter length compensation as well as changeable coordinates.  I have a buddy who does wicked things with those features, way beyond the obvious.  He was my teacher for my Okuma-Howa certs in lathe and mill.


                            Always clamp your stuff down really, really well.  Your machine will vibrate.

                            1 of 1 people found this helpful
                            • Re: Basic CNC

                              Like, IIRC if he is cutting a lacuna for an Allen screw, he just lies to the machine about his tool radius to cut the void for the head.  If he wants a sequence of groves that get smaller and smaller, he uses a for loop to increment his cutter radius compensation.  Not my style, but it works for him quite well.


                              If you are drilling anything hard/thick, use a technique called 'peck drill.'  This will keep you from getting fouled up by your shavings.


                              Cutter compensation allows you to use this kind of drill unique to CNC that is sorta like a burin.  It can make different sized holes with the same tool.

                              • Re: Basic CNC

                                The step drill will work well on materials that tend to fray, it makes very clean holes.  Now that I am a little more awake, I recall that there is a kind of tap for CNC that can produce both chiralities of thread.  It relies on the tool to turn it and plunge it at the same time.

                                • Re: Basic CNC

                                  You're probably right, MK, I could be thread-jacking a little bit.  I own a conventional machine shop, but typically use other people's stuff if I need CNC.  I recently bought a 1KW laser table with a bed almost the size of a half-sheet of plywood with a rotary option.  So, not to be outdone, my buddy gets a 20KW unit with O2 lance and Nitrogen quench for the corners.  Worked well 'til he got lazy with his shut-down sequence the first time out.  Now he is waiting on a new tube!


                                  Like I stated earlier, this neighborhood is simply awash in CNC tools.  My buddy just got a CNC press-brake that predicts the outcomes based on material properties.  He hasn't got it all figured out yet.  When I think CNC tool I am thinking something that had an initial sticker price compatible with that of a McMansion.  Couldn't refrain from mentioning the LR taps, though, just discovered them, had to do a double-take

                                  • Re: Basic CNC

                                    Sure!  I ran into a friend at the beach since the last time I posted, gotta say it was a pretty pretty sunset.   Anyway, he informed me that Pumping Station One has voted to get a largish plasma table.  Those things cut steel like my laser table cuts acrylic.  He works for an interesting business, they make large plywood robotic dragons for festivals and chi-chi weddings.  Says it slows up in winter, however.  PS1 nucleates all kinds of small businesses.  Judging from the smile he wears on his face, I infer that working with robotics, fire and hula girls is hella fun.


                                    Another friend of mine got involved with the machining program at a local junior college when they got a huge sum of money from the Obama administration to set up a completely state-of-the-art fabrication program, the goal of which is to represent all modern fabrication techniques.  I am happy to say that practically all of the major manufactures of this stuff are climbing over each other to donate their best machines.  This freed up money for the school to build a huge (cliché warning) state-of-the-art facility off-site.  He is saturated trying to learn all of these exotic machines.  He has even gotten some material donations!


                                    Chicago doesn't disappoint.  I must say that my son ran off with my tools to Portland Oregon, but the weather is nice there now and he has some time off and a nice compound, so we could visit.  He recently acquired a medium-large mill.  He is using my stuff for a laudable cause:  Multnomah County ARES


                                    But she is surrounded by industrial farmland for miles and miles.  Two places we have found for outdoor recreation that are somewhat local are Manistee, Michigan and Carbondale, Il.


                                    There is an disproportional amount of young women here as they are more given to leave the farm for big-city life than their brothers.  There is a large culture here trying to adapt robotics and other technologies to art and social purposes.  Lots of capital, lots of events and festivals.  Fun, Fun.  Winter used to be a lot of fun here, we would go skating and tobogganing, but with global warming it has turned into a rainy miasma, often.