Not quite a new member but...

[CharlieRam]

Hi, thanks for the advice. I knew I forgot to put something in there! This is primarily just a hobby but who knows, maybe I can start making some bespoke items to start paying for the machine and as such I started with a machining area of about 600mm x 800mm but because I have built a few arcade machines I am leaning more towards 600-800mm x 1200-1500mm. I am still not sure how big I want to go yet but I would hate to build a machine only to find it is too small for any of my projects, although if it is an open end design I could always machine one half and then flip it.
If I use 1610/2010 ballscrews, how will this affect the cutting of aluminium or accuracy, what kind of feed rates could i expect from a well tuned setup with 1605?
I was planning on using the channel in an L or T configuration for the gantry anyway but do you mean also for the base because I would have them spanning the bed also but not directly butted to each other. The drawing was just a quick sketchup to explain how I plan to join the channel to the plates.
Also I have no access to a mill, lathe or anything at the minute, what do you think my chances are of producing anything decent with just a pillar drill and vice? I will obviously have to find a way to face the ends of the channel but first things first I will get some drawings done and see what you guys think.
Also I will have to take a look over Jonathons build to see how he did it.
Lots of questions still and I have been reading lots!

[JAZZCNC]

Narrow and long is the stronger option so if you work on 1/4 -8x4 sheet size then 700 x 1300 is good cutting area and you'll just about get away with using 16mm screws.
The speed you get from 1605 will depend on a few factors, mainly the size of steppers your using and the voltage your running them at. Voltage is key to performance from steppers but everything else like drives etc has to follow suit and match to get best performance.
Now it basicly boils down 2 options you'll have here.? To use drives that take upto 50V or drives that take upto 75-80Vdc. If you used 50Vdc drives then you'll run approx 44Vdc PSU and with 80Vdc drives 70Vdc PSU. These will yield approx 3500mm/min and 5000mm/min of safe usable feeds with 1605. This does depend on other factors so only a very rough guide, in practice you could tweak out more rapid speeds but won't be reliable for cutting.
Now problem with 5mm pitch and soft material like MDf wood etc is that the correct cutting feeds for finsih and tool life are always at your upper limit of speed range or above and this leaves you in funerable position for missed steps and stalls due to how torque drops away as RPM's rise.
So with 10mm pitch you still have the speed but now your motors are spinning at lower RPM for the same cutting feedrate but with much more torque available for when things get sticky etc so no steps get lost or motors stalling.

Resolution is still more than enough for cutting aluminium unless your wanting to cut very high detail, in which case your probably building the wrong design of machine anyway.!
To give an example of the kind of detail 10mm pitch will get you see my aztec calender.

[CharlieRam]

Resolution is still more than enough for cutting aluminium unless your wanting to cut very high detail, in which case your probably building the wrong design of machine anyway.!

What kind of tolerance's would I expect to achieve with hiwin rails and 2010 ballscrews and would it be much worse with supported round rails and what kind of machine should I be building if I want precision?
Cheers, Charlie

[JAZZCNC]

What kind of tolerance's would I expect to achieve with hiwin rails and 2010 ballscrews and would it be much worse with supported round rails and what kind of machine should I be building if I want precision?
Cheers, Charlie

Can't honestly answer that question because there's far more too tolerence than just the screws or rails you use.! Machine Design and build quality all play big part in this. I can tell you cheap chinese round rail is far inferior to profiled linear rail so if your chasing high tolerences then forget round rail.
Also If your on a budget then Chai at linear motion bearings is now selling Profiled linear rail at very good prices which makes using round type pointless. I've used loads now and they are good for the money. Not quite Hiwin quality but much cheaper and not far behind.

If you need high tolerences then you need a very ridged and stiff machine in which case provided the size required isn't huge then a fixed gantry machine is much better design.

[CharlieRam]

Ive had a look on chai's ebay.com shop, Ebay.co.uk shows nothing in his shop for some reason but even on the us site all I can see is supported round rail, no profile rails at all? does he have a shop other than ebay?
Thanks, Charlie

[JAZZCNC]

Ive had a look on chai's ebay.com shop, Ebay.co.uk shows nothing in his shop for some reason but even on the us site all I can see is supported round rail, no profile rails at all? does he have a shop other than ebay?
Thanks, Charlie

I don't deal with him thru ebay I deal direct. Have no fear doing this with Chai he's 100% ok to deal with and trust. I'll PM you is Email address just send him an email for a quote.

[Jonathan]

I see no reason not to post Chai's e-mail address, so to prevent Jazz feeling compelled to PM everyone, it's cyxfred AT alyun DOT com.

To give an example of the kind of detail 10mm pitch will get you see my aztec calender.

Now try one half the size:

[JAZZCNC]

I see no reason not to post Chai's e-mail address, so to prevent Jazz feeling compelled to PM everyone, it's cyxfred AT alyun DOT com.

I don't see any problem either nor do I feel compelled to PM. I do it because I don't mind helping and the Forum rules won't let me post it correctly so what's your problem with that.?

[CharlieRam]

Well I'm back again! After a long Hiatus and pricey divorce I am a free man, not so much spare cash nowadays :) but happy and now have time to pick up my hobby again. I need to read though my thread and check on any advancements in motor drivers and controllers before cracking on but i'm determined to get this thing finished before I'm 6 foot under!

[Lee Roberts]

Welcome back :)