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Hi Bart, welcome to the forum mate and don't stress over hijacking the thread, someone needed to bring it back to life.
Jim, honestly everything is as it was few months back, i.e. in pieces. Once I've got the control panel built and I'm happy the way it works, I'll make a schematic and post it for you. It will be quite tricky though coz' it uses a few linked relays.
Jazz, nice to see your back and in full swing.
Hi,
Thank you for your interest in my design
I guess I should have started with some spec of the design.
Frame dimensions
W x L: 1400mm x 1800mm
Red and Blue is steel
Yellow is aluminium 10mm thick
Linear rails
X: 1800mm x 25mm
Y: 1350mm x 20mm
Z: 380mm x 20mm
Motors:Four Sanyo Denki 103H7823-1730@$80 each - 4A, 2,2 mH, 0,65R, ~2 Nm up to 600 RPM
http://www.plccenter.com/en-US/Buy/
any suggestion of better value for the money?
Driver :TB6600
Gantry
Steel square profile 80x200x (4 or 5)mm
Z axis aluminium plate is all 10 mm
That's what I'm hoping for but almost every seller has a picture of slightly different design so I was wondering if any of them is better or more reliable then other.Quote:
Originally Posted by JAZZCNC
I've just google wire/drum and it's called cable drive and it's not as easy and cheap as it seams - if it is to be precise.Quote:
#2: Honestly there is no solution to match driving from both sides whether twin ballscrews, R&P or belt drive it's by far the best and easiest way to get accurate stiff machine. The wire/drum is just a bodge and best doing it correctly first time.?. . You'll only end back there in the end.!!
Unless your machine is narrow format, which it doesn't look, then single screw just won't work good. Making gantry wide helps but there's a limit before it gets unusable or feasible.
Belt drive is ok but it has a disadvantage of not reducing the moment of inertia of ballscrews. Right now, one ballscrew
has an equivalent mass of 60 kg, that is as mach as moving mass for X axis and same moment of inertia as motor.
Yes, I've seen the spec for the linear rails and linear guideways and bot of them are pretty strong for the size.Quote:
#3 Can't answer that question without knowing which make and what size linear rails. What I can tell you is even the lower quality units are capable of handling forces far beyond what you throw at them or what your machine design will handle, so it will fail long before they do.!!
So for the X axis, moving mass is 60 kg and max force when cutting would probably be around 500N which gives (simplifying) 125N per linear bearing.
However, when i asked about flexing of open bearing, what I had in mind was an order of magnitude. Is it 1 um, 10 um or 100 um of flex.
Homemade PCB milling machine - YouTubeQuote:
#5: Show us and will comment but until then not sure what you mean.?
start watching at around 1:35
Absolutely right :) - I've noticed it some time ago but i was too lazy to change all the constraints :)Quote:
Now your design.?? . . . You have a problem Houston (several actually).!!! . . . . but this one Is a common mistake easily missed.!
The linear bearings on the Y axis can't possibly be fastened like you have them drawn.? Chicken and egg problem.!! Fasten plate on one set and you can't access the bolts for the other bearings.!!
here is an updated photo
Attachment 9364
It's 10 mm aluminium plate - what do you think it should be?Quote:
I'd also consider using different thickness material for the Z axis.? Those thin plates, even with the bracing will resonate while cutting which will affect quality of finish.
I was thinking about making a sandwich of wood and aluminium to dampen vibrations. What do you think?
Sorry for slow replay but i was too busy to write a post
Best regards
Bart
Adil, what's occurring mate, still building this thing ??!Quote:
Originally Posted by Iwant1
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