Yet another CNC project (Build Thread)

[MattH]

Got a bit more done today, I cut the two remaining plate on the CNC router. These are the plate the spindle mounts to and the plate that mates to that and is welded to the top of the spacer. The spindle has a keyway and the plate has a matching one to keep it aligned. The bottom of the spindle has to T-slots for T-nuts, I have ordered some, these will bolt through for the back of the spindle plate and the spacer plate has recesses to account for the bolt heads.

 

[MattH]

I then moved on to the piece of box section that makes up the body of the spacer, after cutting it ti size on the trusty bandsaw,I squared it up in the mill and skimmed both ends to ensure it is parallel.



I also cut some fillet pieces out of 10mm plate on the laser. I will tack it all together, I can use the machined edges of the top and bottom plates to insure that the plates are co-planer. Once it’s then fully welded I will skim both the top and bottom faces to bring it back to parallel.



The plates are 12mm thick and the piece of RHS is 250mm x 150mm x 12.7mm wall. I will grind a weld prep into all the parts and we’ll see how my 250A Paton mig does. If it’s not up to it then I can stick weld it, or even Tig it with the 300A set.

 

[MattH]

C19 has delayed play!

 

[MattH]

COVID has whipped out any progress this week, I’m going into work for a bit tomorrow to get some orders out the door but still not up to machining.
I did pop in today to collect a parcel, the new rails for the Y axis showed up.
Next week I can weld up the spindle mount and get the Y axis saddle machined, the build should move along fairly quickly now.

 

[MattH]

Cut out some sheets of mdf today to stack together and mock up the Y axis plate.
This will be cut from a 60mm thick slab of aluminium so I need to confirm everything is correct before committing to cutting.

 

[MattH]

Worked on getting the spindle spacer finished today.

I surfaced the two plates (on the weld side) on the Europa mill first.
Then I Ground a weld prep on the fillets and rhs.
Tacked the base plate, rhs and fillets together, the little Paton250 did a great job. I was using 1mm wire at 28v and 12m/min wire feed.



I then fully welded up the part without the top plate. Once welded I bolted the top plate in place and aligned it on the mill.

 

[MattH]

After I finished welding up the top plate I skimmed the top and bottom on the mill to remove any warpage from the welding and tapped the mounting holes for the spindle plate.



I then test fitted the spacer and the spindle. The keyways in the spacer seem to have closed up a little from the welding so I will need to remove it and file it out a little. I will probably powder coat the spacer before refitting.

 

[MattH]

Tomorrow I’m going to undertake machining the large aluminium slab that makes up the Y axis saddle.

 

[MattH]

Got one side of the Y saddle machined today.
I’ll finish it off and fit it tomorrow:

 

[MattH]

Finished matching the Y axis saddle plate today.
After fitting it i cut a test plate for the table from MDF and test fitted the table.

 

[MattH]

The Y axis table plate and the motor mount are now done. I’m just waiting on a longer T5 belt.
Only thing left to cut now are the two sprocket carriers which mount on the top of the column.

 

[MattH]

Cut and mounted the sprocket carrier today that support the counter weight chains.
The carriers are cut from 1” aluminium with 15mm aluminium bases.

At the end of the day I also laser cut some small mild steel brackets that the chain can attach to, I just need to weld these on to the spindle spacer and counter weight plate which I will do tomorrow.

 

[MattH]

Welded on the chain links today and mounted the counter weights. Had to shim the right side sprocket carrier up 2mm to match the chain tension.
I also got the Limit switches and cable chains out to see were and how to mount them.

 

[MattH]

so I’ve been doing a bit of temporary wiring and have now got the mill moving. Today I added the limit switches:



Here’s a short bud showing the test movements (towards the end):

 

[MattH]

Waiting on Parcelforce to deliver my spindle inverter that was scheduled for delivery last Tuesday.
In the meantime I’ve updated the software and the screen set I’ve used, installed the X and Z cable chains and finished wiring the limit switches.
I’m waiting on some smaller cable chain for the Y.

 

[MattH]

Progress on the mill is moving along a treat.
I’ve finished installing the cable chains, installed all the oil lines to the X and Y axis.
I squared up the X and Y axis and calibrated the Y rails.
The table mounting plate is now in place and I have added the table, I still need to locate and drill the table mounting holes (the wire is for the tool setter).
I have mounted and done the power wiring to the VFD, this is a Sako 1ph 220v - 3ph 380v 7.5kw inverter so I can run the mill from a domestic supply. It has a 1Kw external braking resistor as I think the internal resistors would struggle to slow a large tool down in under 10 seconds.
I’ve also roughed in all the pneumatics, these are for the tool collet, air seal / purge, future ATC functions and mist and air cooling.

 

[MattH]

After finishing most of the spindle and pneumatic control wiring, I’ve now finished off lots of little bits, I’ve levelled the mill, trammed the table, mounted the vice, trammed the spindle etc.
Today I ran some test cuts, the mill is very solid and therefore makes very little noise, heavy cuts which would have the router screaming, are chatter free. A 10mm single flute cutter, 20mm DOC, 2mm axial engagement, 18,000rpm at 3000mm/min is super smooth:



I did a few different cuts with different cutters, a fly cutter, a shell mill etc. All cut really well.
I also cut a 25mm cube to test accuracy, this came out 0.04mm under in X and 0.05mm under in Y.



I went in and tightened up the servo tuning, it was well out and very soft. I didn’t cut another test piece after but I’m sure it will have made a difference.

 

[MattH]

 

[MattH]

Today I wired in the tool setter and touch probe.
Just before I left the workshop I ran some test tool paths on a piece of 5000 series Ali, this is for a batch of products I will be making from some 7075 Ali.

 

[Hood]

You better get an enclosure built pretty quick