Thor, or should that be Zeus?

[JAZZCNC]

Anyways, Jazz, I did send you an email a few days ago about AC Servo setup in case you had time to look at it please?

Sorry Chaz you'd been dumped into Spam box and I've been really busy so not checked lately. When get chance later in week I'll reply.

[JAZZCNC]

One other thing not mentioned or consdiered is weight.?

The combined weight of Spindle cartridge, motor and all that concrete will most likely require some form of counter balance. Servo alone unless large KW won't be enough I think.

My big mill has got Int40 (Same as taper BT40 with slightly different holder) spindle with 5.5Kw Inverter Motor which spins at 7500rpm and the motor alone is too heavy for one man to safely handle. The pulley alone (which uses 2 x multi V belts not HTD.!!) must weigh same as 2.2Kw spindle.

Recently I removed the head unit from column and reckon it must weigh 500kg. There is 10" sqr 3ft long Solid steel block runs down the centre of column that counter balances it. The whole thing can be lifted up/down turning the ballscrew by hand.!!

[Davek0974]

Thats a beast JAZZ, what sort of size rail does the head/bed run on??

[JAZZCNC]

Thats a beast JAZZ, what sort of size rail does the head/bed run on??

Certainly is That's the Full beast before took it from my friends place, just need to get it finished it's in lots of heavy pieces at minute. Been going to update thread I started so watch out you'll see it in pieces.!! . . . . Built like tank and weighs about same.!

The head and carriage run on 3" chromed box ways the bed runs on chromed Dove tails all fitted with piped lube system handled by controller so constant lube while moving.!! . . . Floats like butterfly stings like Bee-astard if get in it's way. . .Lol

1.8Kw Ac Servo's connected to 32mm 5m pitch C3 Ground ballscrews with 2:1 ratio with 5.5Kw Spindle spinning 6" face mill in back gear and don't stop for anything, be that clamps , vices, people or walls.!!! . . . . Scary Can't wait to get it chomping properly.

[Chaz]

One other thing not mentioned or consdiered is weight.?

The combined weight of Spindle cartridge, motor and all that concrete will most likely require some form of counter balance. Servo alone unless large KW won't be enough I think.

My big mill has got Int40 (Same as taper BT40 with slightly different holder) spindle with 5.5Kw Inverter Motor which spins at 7500rpm and the motor alone is too heavy for one man to safely handle. The pulley alone (which uses 2 x multi V belts not HTD.!!) must weigh same as 2.2Kw spindle.

Recently I removed the head unit from column and reckon it must weigh 500kg. There is 10" sqr 3ft long Solid steel block runs down the centre of column that counter balances it. The whole thing can be lifted up/down turning the ballscrew by hand.!!

Yep, this is a valid concern. This is probably another reason why I will be a bit limited. That said, I could look at doing something to counterbalance - just adds some cost / time to the project.

[Davek0974]

Yep, this is a valid concern. This is probably another reason why I will be a bit limited. That said, I could look at doing something to counterbalance - just adds some cost / time to the project.

Time and cost yes, but your head is going to be pretty heavy so i reckon it will be best building in some sort of counterbalance now, could be hard to add later. This is likely why bigger machines have a fixed head/column and moving X/Y bed - you cant slam the head around if there is half a ton of counterweight hanging off it ;)

[Chaz]

Some pricing from Posa for reference.

1
Spindle for
CNC Machining Center
Built-in
EMS-30
12,000/ 15,000 RPM
SET 1 USD4,225
2
Spindle for
CNC Machining Center
Belt Drive
DS-BT30
15,000 RPM
SET 1 USD2,630
3
Spindle for
CNC Machining Center
Belt Drive
DS-BT30
12,000 RPM
SET 1 USD1,840

http://en.machine-catalog.com/adsl/O...atalog/214.htm - you can find teh details in there.

[Chaz]

Some update after a long absence (and winter).

Gantry is now epoxied to the main structure. Waiting for the epoxy to harden fully before taking away the jacks / hoist to see if it holds the estimated 700 kg gantry.

Busy drawing up the proxy mount parts and did some testing with them.

Id like to add limit switches, can I use proxy switches in series or best to go mechanical for these? I want to use all in series going to a single input in CS Labs / Mach 3.

[Chaz]

So, an update.

I managed to epoxy the gantry to the main body. Scary stuff this. Will some 'glue' hold an estimated 750 kg weight? Seem it does.



Next step was to rotate the mass and remove the table as I needed access to the rails.

Ignore the loose rails in the middle of the lower part.



I then, with a lot of effort, lift my 300 kg 'reference' onto the rails, align and mount so that I can use this to get the epoxy set against the gantry.





The nett result is that I have something that moves forwards and backwards that is aligned to the bottom rails and should therefore be square once moulded. I should be doing the epoxy pouring this weekend.

Some of you might note that the reference part is only 50% of the width of the gantry. I dont have a larger reference surface and using it on its side means it will be too low.

So two options. I can either mould this width and then use a surface plate that I have and basically overlap until I get the full width.
Second option (and what I have gone for) is to basically put 100mm wide (the rails are only 40 but I need some extra height for the adjustment up and down) 30mm thick alu tooling plate (Eco Cast). I know its not perfectly flat but I am hoping this will be reasonable. Ill bolt this to the reference square and see how this looks.

https://youtu.be/ZtDXA0xAFhQ

[Chaz]

Sorry Chaz you'd been dumped into Spam box and I've been really busy so not checked lately. When get chance later in week I'll reply.

Thanking you.