Hi Guys, first post here so please do set me straight if I do something which is all wrong. I would like to put together a frame with four driven heads to simulate a „dipping process“ for a preproduction study. (My sketch is attached) it is basically just a straight line from pickup—> dipping —> short spin of the 4 spindles —> ejection. The path I need to follow is approximately 700mm along the Y-axis, 400mm along the X-axis, and 150mm along the Z-axis. I would need a quadruple tool holder (like 4 Dremels) that can operate in the range of 5,000 to approximately 35,000 RPM and can be turned on off in the cnc program. The CNC should perform a very simple task of dipping parts into a liquid: a) Loading position at X200, Y0, Z0 b) Moving to the dipping station at X200, Y400, Z0 c) Dipping to Z-125 d) Rising to Z-90 e) Activating all four tool holders simultaneously for about 1 - 2 seconds f) Rising to Z-55 g) Moving to X200, Y615, Z-55 h) Lifting to X200, Y615, Z-50 i) Returning to the start at X200, Y0 j) Moving to X200, Y0, Z0 I wonder if controlling four spindles simultaneously is possible if so what I would need to do so.. thanks for taking the time to read through this long post, Guys your inputs would really help. Donat
I am guessing that the parts being picked up are quite light, and that the 'pickup' operation is something like pressing a block into a mould where the item naturally sticks to the block, rather than needing an actuator to clamp onto the object. My gut feeling is yes, this is all very doable. Looking at something highly 'tweakable' like a Lead 1010 machine with the high-Z option, and considering what physical modifications may be needed to support the 4 spindles would be a good place to start. For something like dremels, it may need a modified plate for the Z axis that allows 2 dremels to be put on one side of the gantry, and two on the other, depending on how far apart the dremels need to be separated. If they can be physically close together, then just modifying the existing plate and putting 4 Z-axis mechanisms on, with a belt drive arrangement to turn all four simultaneously would not be too diffcult. If the separation has to be large, then using an arrangement of belts from a single z stepper to drive all 4 Z actuators can still be done, but the machine may need a 'second gantry' to make it more stable (which may only require new plates for the Y axis to be designed, or a pair of Y plates somehow 'bolted together'). As for engaging the 4 spindles, most controllers (e.g. an openbuilds black box) have the option to drive a relay output, which may either drive 4 small dremels wired in parallel, or trigger a larger relay/ bank of relays to engage the spindles. Turning the spindles on and off would then be done in the G-code programme. Under the machine, it would not have the usual MDF wasteboard of course, and a bespoke frame may be needed to support the Y-axis legs over the moulds and conveyor etc.
Hello Evan thank you so much for your detailed reply. How you described it is pretty much exactly how Ill be setting it up. Ill upload a sketch. Ill first make a very cheap prototype before going fully fledged. Regarding the dremels or drives, Ill use the Yaxis stepper to drive my tool as all I need is to spin the four tools at just under 3.5Krpm for about a second. I can program that in the Gcode. Evan, thank you for your quick reply and ideas. Have a great easter Donat
Hi Donat, Looks good. Does the unit that takes the single stepper Y drive in and creates 4 (flexible) drives out have any gearing in it? Many standard stepper motors struggle to run as fast as 3.5k rpm as the availalbe torque falls off quickly with increasing rotation rate. If there is no gearing, then a belt drive between the Y stepper and the drive splitting unit with say a 1:3 or even 1:4 ratio may be worth considering to keep the stepper rate to around 1krpm. Evan
Hi Evan, Yes most likely a 1:2 will be used with a belt… I think that should do… I have also ereised the wholesome thing will need to be ATEX safe so will have to work something out with a cut off switch based on the combustibility in the closed “case”
