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I have project to do at work trying to use a CNC to pull / feed a wire around some pins
But am struggling to get the speed required no real force required as is normally done by hand.
Need to be able get 8 meters a minute or so feed rate
Any ideas ?
Faster pitch lead screws ?
:dread:
Sorry the crystal ball is away for polishing so need more details about what you have on the machine. ie: Motor details: 4wire, 8wire ,Nm, inductance. Drives: rated Max voltage, Microsteps. PSU type and voltage. Screw pitch, diameter.
What I am asking is that what do I require?
we tried a system 6040 of eBay and it was next to useless + Very loud 77db was sent back
Ok so you haven't actually got a machine and you are asking what a machine will need to move faster than 8mtr mins.?Quote:
Originally Posted by Wildrat
I have a Machine at home am working on photo below
But we did try a machine via Ebay had some issues with the software when sorted that found it was no good to slow and noisy
We are still looking to the same job at work but needs to be fast as has to wrap some stainless wire between some posts in 5 seconds ish
Looking for recommendations ideas
Thinking of building new unit but with faster pitch lead screws ?
Ok well, several factors will come into play to do this and get the speed and acceleration you'll need. The screw is one but motors, drives and PSU are also very important and if you want really fast so is the controller. I'm going to assume your thinking to use Stepper motors rather than servo's to keep costs down.
First, the screw indeed would benefit from being a higher pitch but it also needs to be the smallest diameter possible to keep the inertia down, this will allow higher accelerations which you'll probably need.
Next, the Motors need to be a low inductance motor so they can spin faster and hold torque higher up the speed curve, these need to be connected to drives that allow a decent amount of voltage. Steppers get there speed from Voltage so the relationship between inductance and voltage is key.
The PSU is also important with fast-spinning motors and screws because it needs to be able to handle any power being sent back from the dynamo effect when de-accelerating from high feeds.
Now, 8mtr/min isn't fast for a router and any of the setups we use for a good router will easily top 10mtr/min humping a decent weight gantry around so I'm going to spec this like it's a medium-sized router and based on using Steppers.
Motors:
3 or 4Nm 8 wire nema 23 with an inductance around 3-4mh. The 8 wire type is preferred because can wire it parallel to get the best speed.
Drives:
Digital drive with Max voltage 70-80Vdc or 40-60Vac, it's becoming more common for drives to offer both DC and AC as it's easier regards PSU.
PSU:
If using DC then unregulated PSU is required and the best choice is one made using toroidal transformer and capacitors which is sized to your needs.
This type of PSU allows the capacitors to absorb any power coming back and also provides a nice smooth supply of power for the drives. The transformer will need to be sized to suit the drives/motors so I won't spec that now. When you have decided what your using I will help you choose the transformer.
If using AC drives then it's simply a case of sizing transformer slightly(roughly 10%) smaller than the drives Max voltage.
Screws:
16mm Diameter 10mm pitch will work and because your probably not going to be lugging a heavy gantry around then with the above electrical spec you should easily reach 15mtr/min. If you wanted more speed then go with 16mm pitch and you'll be into 25mtr/min region.
Controller:
For high speeds and reliability, you really need a good controller. The parallel port is limiting in the number of pulses it can provide and the faster you go the more you need. It's also very flaky so best avoided.
So external motion controllers are often used, some use USB but the best to use are Ethernet-based because they are most reliable.
There are several manufacturers but common good ones are Cslabs and Motion controls products UC based controllers like UC300. Any of these will allow you to what you want.
Hope this helps. Ask if need to know any thing more.
We got a standalone controller to run unit
https://purelogic.ru/data/docs/elekt..._manual_ru.pdf
Would this be OK for high speed ?
Do you have any one in UK that would recommend to buy off ?
Yes but that's just a Chinese controller which you could buy a lot cheaper on AliExpress or Ebay.Quote:
Originally Posted by Wildrat
Don't know anyone in uk who sells them.