Bench-top or welded frame

[Doddy]

Hi doddy,

What work area are you aiming for?

Bigger than my StarMill (160x100!). Height isn't a massive issue for me (at least not as yet), but 200mm would be an aim. X/Y = around 600x400 was my goal.

Did you concidder going vertical?
This might solve some of your space problems.
And you could move through doors more easy.

Only the crazy people go vertical! Actually, it's something I had just started to think about - I know Dean here has done this in the past. That might be the next machine.

Will there be a rigid fixed connection between your gantry sides?
How do you prevent gantry going out of square?
Your design does not look like it has a rigid gantry now.

(assuming you mean square across the Y-Axis) Yes, a beam across the top, with gusset plates to hold square (sorry, the design is obviously incomplete - more to get the concept right in my mind before burning hours on Fusion 360).

Is it made out of 3 separate moving parts?
I think it will be very hard to get a rigid end result that way.

Yes, more steel to be added yet. As above, this is just a basic geometry sanity check.

Also the spindle is not in between the linear bearings, this also does not help for rigidity.

Now for me i am no expert. So please have the more experienced guys here point you in the right direction.
I started my cnc design reading at cncroutersource then came here :-) Still on a steep learning curve.

My 2cts worth,
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That's exactly why I posted this. Placing the spindle where I did I'm very conscious that it's putting a large force on the rails. Having said that, better and brighter people than me have suggested that the rails are more than strong enough for anything a small machine like this is likely to throw at them, and Dean's earlier comment re. most mills - yeah - they'll place a similar cantilever load on the rails as well.

[driftspin]

Bigger than my StarMill (160x100!). Height isn't a massive issue for me (at least not as yet), but 200mm would be an aim. X/Y = around 600x400 was my goal.




Only the crazy people go vertical! Actually, it's something I had just started to think about - I know Dean here has done this in the past. That might be the next machine.



(assuming you mean square across the Y-Axis) Yes, a beam across the top, with gusset plates to hold square (sorry, the design is obviously incomplete - more to get the concept right in my mind before burning hours on Fusion 360).



Yes, more steel to be added yet. As above, this is just a basic geometry sanity check.



That's exactly why I posted this. Placing the spindle where I did I'm very conscious that it's putting a large force on the rails. Having said that, better and brighter people than me have suggested that the rails are more than strong enough for anything a small machine like this is likely to throw at them, and Dean's earlier comment re. most mills - yeah - they'll place a similar cantilever load on the rails as well.

Hi doddy,

What is your main problem with exiting 6040 designs?

I feel like the " lean back " gantry design is most space saving.

Do you think 20 mm alu gantry sides will cover your rigidity needs?

http://www.mycncuk.com/showthread.php?t=11610

like that one... but a bit smaller.


Grtz Bert.


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[Doddy]

Hi doddy,
What is your main problem with exiting 6040 designs?

Significantly - I want to do as much of the build myself, and (to an extent) I can work with steel. Having said that there's a recent threads that show some very enterprising use of hand tools (though throwing a woodworking hand held router through 20mm of alu would certainly be different to what I'd normally use it for). The design (once I understand it!) is something that I can build with the equipment that I have. To some extent there's a certain curiosity value as well.

[driftspin]

Significantly - I want to do as much of the build myself, and (to an extent) I can work with steel. Having said that there's a recent threads that show some very enterprising use of hand tools (though throwing a woodworking hand held router through 20mm of alu would certainly be different to what I'd normally use it for). The design (once I understand it!) is something that I can build with the equipment that I have. To some extent there's a certain curiosity value as well.

For cost... steel is the cheaper way to build.. there is a catch though.. steel is not easy to get straight/flat enough to mount linear rail directly.

Did you decide on square or supported rail?


Do you have access to tools to get the steel flat level and straight ?

If not.. epoxy is a solution... but not very easy to do.. and not cheap.



Grtz Bert.

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[driftspin]

For cost... steel is the cheaper way to build.. there is a catch though.. steel is not easy to get straight/flat enough to mount linear rail directly.

Did you decide on square or supported rail?


Do you have access to tools to get the steel flat level and straight ?

If not.. epoxy is a solution... but not very easy to do.. and not cheap.



Grtz Bert.

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what about this one?

http://www.mycncuk.com/showthread.php?t=11152

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