7' X 4' Combi

[Ricardoco]

Ive now reduced the Z to 250mm Max and reduced the gantry mass considerably. Im hoping to have the screws/ motors mounted and close to test by tomorrow evening, But i cannot do any tests antil i recieve the two pulleys and belt to connect the steppers together as a precaution against single motor failure twisting the gantry. Im also looking for a source of 1.6mm 8x4 sheet steel, but the delivery costs are more money than the steel itself... Grrrrr


Rick

[JAZZCNC]

Rick If those pieces that look like 1" box are for the bed support then it's not going to strong enough with big chance you'll get bed dipping.
The forces when plunging and ramping etc can be high.! Even my 50mm box with 16mm Ali bed can flex when plunging into hard materials. Honestly don't under estimate the forces.!!

[Ricardoco]

Rick If those pieces that look like 1" box are for the bed support then it's not going to strong enough with big chance you'll get bed dipping.
The forces when plunging and ramping etc can be high.! Even my 50mm box with 16mm Ali bed can flex when plunging into hard materials. Honestly don't under estimate the forces.!!

Hi Jazz, that 1" box is going to be supporting the water bed for the plasma only. The milling bed is going to be much tougher and stiffer. There is a 50x50x3mm box section frame topped by 40x40 profile for the Router/Mill bed that is still in production, you should see that appear about mid march.

Rick

[Ricardoco]

Ok Just building the secondary steel frame that goes inside the main frame for milling/routing, Obviosly im not going to be putting a 7'x4' ali bed on it, the most of it will be a sacrificial bed for routing. So i was wondering what size ali plate to embed in the frame for machining ali. So the question would be. What are the largest size projects you have done and what would be the minimum size ali bed you would choose given the choice, not forgetting quality over quantity and of course price.

I would like as many opinions on this as i can get please.

Rick

[Jonathan]

If at this stage you can't afford or justify getting a piece of aluminium big enough to cover the whole bed, or strips to cover the bed leaving slots, then I'd say the minimum is a piece wide enough to span the machine and long enough to be useful. That means about 4' by something, maybe 1200x600 would be enough to cover most things. The biggest single aluminium part I've machined on my router was 1015x700x25.4mm and the biggest aluminium 'job' so far has been 1480x715x20mm, which probably doesn't help much with your question as it depends entirely on what you're planning on making. Also these parts were machined when I still had an MDF bed, so if the part wont fit on you're aluminium bed it's not the end of the world. Since your bed will be well supported I see no reason to get more than 20mm thick aluminium.

[Ricardoco]

If at this stage you can't afford or justify getting a piece of aluminium big enough to cover the whole bed, or strips to cover the bed leaving slots, then I'd say the minimum is a piece wide enough to span the machine and long enough to be useful. That means about 4' by something, maybe 1200x600 would be enough to cover most things. The biggest single aluminium part I've machined on my router was 1015x700x25.4mm and the biggest aluminium 'job' so far has been 1480x715x20mm, which probably doesn't help much with your question as it depends entirely on what you're planning on making. Also these parts were machined when I still had an MDF bed, so if the part wont fit on you're aluminium bed it's not the end of the world. Since your bed will be well supported I see no reason to get more than 20mm thick aluminium.

Ideally i would like to cover the whole bed in profile, but the cost i suspect would be well over the top, in fact i dare not look although it wont be as much as it was when the bed was 7' but since i rebuilt the bed length at 6'6"x4'. I would love a complete bed ali with t slots but im not sure i can justify the massive percentage of the final cost.....

So your largest Ali machined part was 1480 x 715. Cheers Jonathan.

Ok any more offerings??


Rick

[JAZZCNC]

Agree 1200x600 would be my minimum if planning on cutting thicker Aluminium has most Single parts will usually fit in that space and only if your nesting several parts will you need much above this. Even thou my 1200x1200 bed is all Ali (slots) usually half of it has piece of MDF or HDPE spoil board on it.

If your cutting thin Ali plate like 3-4mm then you'll probably want more space and be cutting large single pieces anyway. So then again you'll probably find an MDF spoil board will be used for holding and bed saving reasons.!

Part holding is a challenge and can be pain also it can be very part dependent.? You'll find even with an Ali bed you'll use some form of protective material or spoil board between part and bed.!

[Ricardoco]

Agree 1200x600 would be my minimum if planning on cutting thicker Aluminium has most Single parts will usually fit in that space and only if your nesting several parts will you need much above this. Even thou my 1200x1200 bed is all Ali (slots) usually half of it has piece of MDF or HDPE spoil board on it.

If your cutting thin Ali plate like 3-4mm then you'll probably want more space and be cutting large single pieces anyway. So then again you'll probably find an MDF spoil board will be used for holding and bed saving reasons.!

Part holding is a challenge and can be pain also it can be very part dependent.? You'll find even with an Ali bed you'll use some form of protective material or spoil board between part and bed.!

Hi Jazz did you make your slots, if so how or did you buy the plate somwhere if so where. I must admit your 1200x1200 seems like a nice size to me as im unlikely to be machining anything larger... Mind you never say never... If i were to go for a solid plate that size at 20mm thick i would be looking for someone else to drill and tap all the holes as I wouldnt look forward to that..

Rick