Fingers crossed it'll cut ally

**Jonathan** · 22-11-2010

I thought the forum had something to stop double posting...oops. That's the problem with having a really slow internet connection.

**Jonathan** · 22-11-2010

Originally Posted by blackburn mark

no, im on a chineese 5 axis TB6560...
its amazing how much more the gantry sides flex in the Y axis compared with the X axis
ill stick some sort of buttress on them if its a problem

I'm not thinking today am I, you mentioned the driver only a couple of posts ago, sorry!

Plate is the worst possible cross section for bending in the Y direction. Maybe you could securely bolt some bigish aluminium angle to the plate to make it a bit stronger...ideally get it welded on.
All that aluminium profile must have cost a lot.

I intend to look at the servo controller on Wednesday, or this weekend at the latest.

**blackburn mark** · 22-11-2010

i was thinking a 20mm arch bolted at 90 down the gantry sides, i need to work out where the torsion might be acting... im pretty sure it wont be a staight line top to bottom

All that aluminium profile must have cost a lot

Owch!! £100 meter, it did hurt spending that much but it is easy stuff to work with and its flat enough not to need machining

I intend to look at the servo controller on Wednesday, or this weekend at the latest.

have you got an ESC for that monster motor yet ?

**Jonathan** · 23-11-2010

Originally Posted by blackburn mark

i was thinking a 20mm arch bolted at 90 down the gantry sides, i need to work out where the torsion might be acting... im pretty sure it wont be a staight line top to bottom

Have you had a look at irving's spreadsheet on this? It's interesting comparing the different sections with it.

Originally Posted by blackburn mark

Owch!! £100 meter, it did hurt spending that much but it is easy stuff to work with and its flat enough not to need machining

Yikes, that's a ridiculous price when you compare it to the material cost.

Originally Posted by blackburn mark

have you got an ESC for that monster motor yet ?

Not quite. According to the website I need at least 100A and 48v ESC, which is going to cost a lot even from hobbyking! I think a lower current ESC should survive as I'll never need that much power. I'm thinking of replacing the mosfets on a really cheap 100A 24v ESC I have for some much higher voltage ones...that should do the trick for very little money.

Alternatively a friend of mine has randomly acquired a 5.5 KW 400v variable frequency motor inverter from a lift. I think it might be adaptable...

**blackburn mark** · 23-11-2010

try "giant cod"
as cheap as ebay for some stuff

irving's spreadsheet

ill have to have a look for that

im not going to use mine at 1700w, i really cant see me needing that much, im not sure the 360w power supply im using will be enough... we'll have to see how it pans out, it would be interesting to see how it dose at 1700w
it has been a real work horse though and the windings dont get very hot

it'll be interesting watching your workshop lights when you fire up that 6000w job :)

**blackburn mark** · 27-11-2010

Errrr..... has anyone had any experience with wiring home switches to an X axis thats driven with two steppers ?

in mach setup documentation it recomends putting a homing switch on each of the two x-axis drives to correct for lost steps and racking which im getting plenty of as im in the tuning stages of my setup... i only have enough inputs for 3 homing switches and an e-stop on my driver board

how do i conjure up a forth input ???????

**Jonathan** · 27-11-2010

A PCI parallel port card would get you plenty more inputs. There's probably a more elegant way to do it though...
Theoretically 3 inputs is enough if you put the switches in series/parallel etc with each X home switch on separate input - it's a matter of if mach3 can handle it. I'd like to know for my router...

I had a look at giant cod (what an odd sentance!). There's some interesting things but it's still a bit more expensive than www.hobbyking.com. Maybe I could use an E-bike controller on my motor.

**HiltonSteve** · 27-11-2010

Jonathan - Just noticed that your after a 100A 48v motor controller, I have got a few kicking around if you want one.

The ones I have take any voltage from 24 up to 48 and also can cope with anything up to 200A, fully programmable through 3 buttons on the front.

Let me know if you want some more information.

Oh, and I am sure the price will be right!

**blackburn mark** · 27-11-2010

A PCI parallel port card would get you plenty more inputs.

i was worried someone would say that... my graphics card is blocking all my PCI slots... ill find a way.
im not going down the "series/parrallel" route with switches, homing and soft limits makes the most sense to my eyes

Just noticed that your after a 100A 48v motor controller

might be a winner :)

**M250cnc** · 27-11-2010

Mark i have not used a slaved axis but you can have all limits on one input, then maybe just the slaved axis on a separate input.

To anyone who wants more IO i use a PoKeys device http://www.poscope.com/product.php?pid=3

I have control panel with hardware buttons controlled through this device even does Speed and feed override via pots, MPG's etc

Phil