Aluminium Profile Type Router - Initial questions

[AndyUK]

Looks like good progress.

As Jazz mentioned you now need to consider trunking and cable runs, at the moment any vertical runs are awkward.

I'd also consider putting the contactor in the high voltage section.

[JAZZCNC]

Here's a couple of pics of boxes which might help give some ideas, These range from tiny 300x300(red) to 800x600 boxes.

There's no one way which is better than any other so don't stress over it, just be mindful of high and low voltage wire separation along with grounding and you won't have any issues.

[CNCRY]

Thanks, Some useful ideas there Jazz, with everyone staying close to home at the moment, I had some time to get the E-stop working along with fixing DIN rails and mapping out where things will go:)
After attempting to drill the first 16mm hole in the cabinet with a normal bit I realised what step drills are for and did the rest.. great tool.




Hoping to have linear motion parts finally this week from BST. Physically building again is starting to feel more daunting then the electronics now.!
Thinking about limits and home too -

From what I understand a limit and home can be the same physical switch.
So I'd expect you need a limit on each end of X axis, with one end doubling as a home. Then the same on Y, and Z can have a single switch passed on upper and lower limit, and say upper can be home.
So not sure why people mention 2 X's being used - surely both limits are at the same point as the 2 X axis are parallel?

Edit - Fuse question. The Transformer will be 750VA - 2 x 65V output. I ordered 10A D curve MCB seen on others diagrams, but I'm thinking 750VA/230V is approx 3A so 10A is very high. Or am I missing something (most likely)

Ryan

[JAZZCNC]

From what I understand a limit and home can be the same physical switch.
So I'd expect you need a limit on each end of X axis, with one end doubling as a home. Then the same on Y, and Z can have a single switch passed on upper and lower limit, and say upper can be home.
So not sure why people mention 2 X's being used - surely both limits are at the same point as the 2 X axis are parallel?

Ok well regards the X-axis having 2 switches this only applies if you are using twin screws, one side will have a switch that works for limits and home, the other side as a switch just for home. Reason being you home each side independently to square up the gantry. But you only need a limit on one side.

Now regards having a switch at each end then there's another way, which IMO is the best way and uses just one switch on each axis.
You place the switch on the moving part ie: Gantry and Y axis which then looks for a target at each end of travel. The Z-axis just uses a fixed switch at the top of travel which looks for the target on the moving part.
This means you have less switches and less wiring to go wrong.This can be done with either proximity or Microswitch type's.

[AndyUK]

Edit - Fuse question. The Transformer will be 750VA - 2 x 65V output. I ordered 10A D curve MCB seen on others diagrams, but I'm thinking 750VA/230V is approx 3A so 10A is very high. Or am I missing something (most likely)

I believe that D curve MCB is sized to cope with the inrush current. A 1KVA transformer will only need approx 4A in steady state on UK mains (varies with min input voltage and efficiency) but the inrush can be something like 100A for a very short amount of time (dimming lights anyone?).

[CNCRY]

Ok well regards the X-axis having 2 switches this only applies if you are using twin screws, one side will have a switch that works for limits and home, the other side as a switch just for home. Reason being you home each side independently to square up the gantry. But you only need a limit on one side.

Now regards having a switch at each end then there's another way, which IMO is the best way and uses just one switch on each axis.
You place the switch on the moving part ie: Gantry and Y axis which then looks for a target at each end of travel. The Z-axis just uses a fixed switch at the top of travel which looks for the target on the moving part.
This means you have less switches and less wiring to go wrong.This can be done with either proximity or Microswitch type's.

Hi Jazz - So as I have twin X screws, if I go for the moving option on gantry I just need the single physical switch on each X (one acts as limit/home the other just home) and I have contacts at each end the switch triggers?
Then Y needs only one switch using same setup?

Thanks

[CNCRY]

My linear motion parts are finally here! Happy with the service from Fred at BST - all parts received and in good order. Took a fair few extra weeks but with the worldwide situation at the moment not at all surprising!



Looks like most aluminium supplies however are shut so maybe time for more electronics..

So today's question - does anyone know of a coupler for a 10mm end of the ballscrew to a 10mm with 3x16 keyway (on the motor shaft)
I got a load of "oldham" couplers from BST but they are 7mm/10mm bore with no keyway. Stupid question but does the keyway detach?
The problem is the hybrid steppers are not standard 7mm shafts!

Thanks
Ryan

[JAZZCNC]

Hi Jazz - So as I have twin X screws, if I go for the moving option on gantry I just need the single physical switch on each X (one acts as limit/home the other just home) and I have contacts at each end the switch triggers?
Then Y needs only one switch using same setup?

Thanks

Yep works exactly as you describe.

[CNCRY]

So I was about to mount my 750VA Toroidal transformer to the cabinet back board with the supplied fixing bolt, metal plate and large rubber washers
e.g this kit > https://airlinktransformers.com/imag...photo1_CM5.JPG
Plan was to drill and tap the metal back plate and secure the bolt into it.
Then I read this - https://diy.stackexchange.com/questi...-metal-chassis
From what I understand the bolt itself plus the top mount plate and chassis can form a C shape around the winding and induct a current. People mention fires and things blowing up which I'd like to avoid!
So now I'm thinking to mount to a phenolic (insulating) sheet so the mounting bolt does not touch the cabinet back plate directly. The transformer also has an earth wire.
Any issues with this, or better suggestion people use?

Thanks

[Clive S]

So I was about to mount my 750VA Toroidal transformer to the cabinet back board with the supplied fixing bolt, metal plate and large rubber washers
e.g this kit > https://airlinktransformers.com/imag...photo1_CM5.JPG
Plan was to drill and tap the metal back plate and secure the bolt into it.
Then I read this - https://diy.stackexchange.com/questi...-metal-chassis
From what I understand the bolt itself plus the top mount plate and chassis can form a C shape around the winding and induct a current. People mention fires and things blowing up which I'd like to avoid!
So now I'm thinking to mount to a phenolic (insulating) sheet so the mounting bolt does not touch the cabinet back plate directly. The transformer also has an earth wire.
Any issues with this, or better suggestion people use?

Thanks

What you MUST NOT do is connect anything to the bolt on the top side that is connected back to the chassis as that would then make a shorted turn. The rubber washers are there to protect the transformer for mechanical damage to the winding.