Hi I need to build a cnc to meet the following minimum requirements: 1. Size a) x depth 800 mm b) y width 1200mm c) z height 600mm 2. Z Head tool requirements a) Needs to hold a tubular glue dispenser above the workpiece. The dispenser weighs no more than 30g having a flexible 6mm plastic compressed air feed supply attached to its top end. A dispensing needle nozzle with a working tip is attached to the lower end of the dispenser. b) The dispenser to be held in V Block c) Two stage control for Z i) Rough positioning of the head tool above the workpiece set by Z ii) Fine control of tool tip needs some form of control (laser?) to accurately measure the distance between the tip and the worksurface and maintain a tip height above the workpiece to an accuracy of 0.05mm. Fine control needs have a range of 50mm. iii) It should be noted that the dispensing needle nozzle and tips vary in length 3. Accurate control of travel speed is required. The possibility of attaching heads to fulfill different functions needs to be preserved. Could anyone give me a push start by nudging me in the right direction? I do like to read up on stuff before I start work so a rteading list would be appreciated. Many thanks David
Hi David Welcome to the world of CNC. Before we go any further, can I direct you to this: http://www.openbuilds.com/threads/cnc-axis-reference.951/ Simply to get us all singing from the same hymn sheet, so to speak. I cannot see any real problem with the demands you have for a CNC type Glue Dispenser. As far as accuracy is concerned we do really good accuracy. When you consider the needs of a model maker or a high detail carving job. The CNC is the tool for the job. The only potential problem I see, is the need for a 600mm Z Axis! That is a big demand, and height, for a stable machine. You should perhaps consider having a fixed and very rigid "X axis" with your Z axis mounted on it, and centred on the Y Axis, then have the "bed" move forward and backwards in the "Y" direction. You could use a mix of belt and screw drives here, or just screws all round. Please have a good read of this Forum. I'm sure you will find everything you need here, it just takes time and persistence. Please don't be afraid to ask any questions, there are a great bunch of people here who are more than willing to help. Cheers Gray
@vizion Do you really need 600mm travel from the Z axis or is that just the height it should be ?? Tweakie.
Good point. How about then, having the Y rails fixed at 300mm, then only needing to move the Z 150mm up and down? Gray
This old thread is exactly what I was looking for, except there is no useful information for how to build a project like this. Can anyone point me to where I could learn more about buildings and and controlling a glue dispensing CNC? I have an ARCO system, ideally would like to add the dispenser unit.
These type of dispensers comes with a foot switch. You can replace the footswitch with the BlackBox's Relay: docs:blackbox:jumper-relay [OpenBuilds Documentation] - sending a M3 to trigger a dispense, then a G4 Px to wait in place for a time, for it to complete the dispension, then M5 before moving to the next coordinate
Managed to get the dispenser setup. I am using the plotter pen firmware, with rc servo connected to "SERVO" and the footswitch pedal to "RELAY". Jumper set to "M8/M9 Coolant On/Off Commands" (M3/M5 are already used by the pen UP/DOWN servo motor). So far it seams to work as expected when sending manual commands, however I am a bit confused on how I can implement the M8/M9 commands when generating the GCODE. Is there a way I can set this up in Lightroom or OBCAM so the M8/M9 are triggered right after/before the M3/M5 commands? How can you setup a custom sequence of events when "printing"? Right now M8 stays triggered for the entire job and M9 at the end of the job.
