Desktop size steel welded router 3 axis

[cropwell]

Hi Jazz,

Here's a question for you - If you are using one switch for home and limit does Mach ignore the limit function while homing?

That leads on to another - If you have slaved motors on an axis does mach wind both motors until a home trips and then keeps winding the untripped screw until the other trips, thus squaring the gantry and then do the backing off the home switch to complete the homing and aligning process ? In which case I presume you would need to have separate inputs for each side of the machine.

I see the point of having 2 targets and one switch, I only recently realised that Mach took into account which axis was travelling and the direction of travel when homing. It makes sense of commoning inputs.

Cheers,

Rob

[JAZZCNC]

Here's a question for you - If you are using one switch for home and limit does Mach ignore the limit function while homing?

Yes if you turn off HomeSW Safety in General Config.

That leads on to another - If you have slaved motors on an axis does mach wind both motors until a home trips and then keeps winding the untripped screw until the other trips, thus squaring the gantry and then do the backing off the home switch to complete the homing and aligning process ? In which case I presume you would need to have separate inputs for each side of the machine.

When using slaved motors Mach De-couples each motor turning back into two separate axis while homing happens which means the motors work independantly but move together in sync towards the home switches. When first switch is tripped that axis motor stops and backs off the switch while the other keeps going then does the same.
In practise provided your Gantry is square and the switches positioned correctly this appears to happen has one action. If your gantry is really out of square then you can position the switches to force it square.
When Both Motors have homed then Mach Couples the Axis again back into one slaved axis.

This does mean that the Slaved Motor needs it's own Home switch on a Separate Input.

[Tom J]

Machining base for X -rails


Had to bend frame in the places to be perfectly straight - left those Irwin for overnight to see if 0.8 mm sag is dissapering

[Tom J]

I managed to get 0.4mm off the sag, better than nothing, will use the technique like those who do not machine the profile or base. Simply will use filler gauge - industrial sheet in the middle to compensate - do not want to have tension on the bearing block while is sliding from middle towards end.


After welding so many frames came up with solution - there is not substitute for slow welding with min heat. Mean the welding bed have to be short and fully cooled before we weld again near by.
I put all theory to the bin with current setting to metal thickness and speed wire on MIG.
I use Clarke MIG TEC230 Turbo which is capable to weld up to 7 mm on max setting (switch pos.6)
My profile is 2-2.5mm with plates 5mm and I use pos.3 - current/power and wire speed min as possible to stop splatter but fast enough to get good constant sound (not like a shooting gun)

[Tom J]

Here is where design doesn't match reality - X drive motor bracket doesn't make the belt tight, I made all the parts in Solid Works myself - using vernier rather than dimensions data and with belt 295mm long error was like 5mm.
No big deal - 1hr+ lost for fabrication.

Here is the gantry. X motor bracket I will made longer and than will cut slots for adjustments. Lesson learnt

[Tom J]

Another fabrication day.
Done some welding, this time I used 0.6mm wire for trial. Have to say that I am happy with results as my profile thicknes is 2.5mm and other plates are 5mm at this stage.

Welding is all about heat control and avoiding distortion.
Here is my setting for 0.6mm MIG

All major welding is done I believe. Cable chain-carier, table top, sensor will be bolted.
Here is some shots from today:

[Tom J]

Time for Y axis drive. Gantry legs will be connected under the bed by flat steel 50x5mm.
I will use only one ballscrew for moving the gantry as this is desktop size machine (travel distance from left to right is 300mm, forward and backwards only 220mm).
I sacrificed 80mm of travel on Y for bigger distance between bearing block - stiffness won.

Had to fabricate Ballscrew nut bracket today - picture later.
Than I can center the ballscrew mount (front and back) so there is no tension on screw when turns backwards/forward.
A lot of steps in fabrication depends on previous - all related. Can not jump forward without doing something which have to be done first. Sometimes I loose the plot and do something what shouldn't be doing at that time like - pick up for sensors:

or sensor bracket/s