Design help etc required with DIY CNC Router Design / Build

[MikeyC38]

I got the order changed . Am ordering the bits from linearmotionbearings2008, which many have spoken of well. I'll get a drawing done so the more experienced on the forum can critique. The long axis design should be ok with the vertical loads on the rails, but on the short axis with supported rails not too sure here - as there are torque and vertical loads from the z-axis carriage and router to account for - the top bearing carries vertical and torque and the bottom bearing carries the torque loading only. I'm sure you guys will steer me appropriately

Thanks
Mike

[Jonathan]

on the short axis with supported rails not too sure here - as there are torque and vertical loads from the z-axis carriage and router to account for - the top bearing carries vertical and torque and the bottom bearing carries the torque loading only

You can resolve the forces and moments on the bearings, I did it here:

http://www.mycncuk.com/forums/showth...inear-bearings-...

But it doesn't really achieve much except for deriving the obvious (space the bearings out as far as you can afford to, and minimise overhang) and showing what I said in my previous post.

I got the order changed

Excellent - what did you change it to?

[John S]

Excellent - what did you change it to?

Two bacon butties, dill pickles and a side order of chips..............

[MikeyC38]

Two bacon butties, dill pickles and a side order of chips..............

Hi John S - If only! only allowed 1 bacon butty a week on my diet!! -:)

[MikeyC38]

You can resolve the forces and moments on the bearings, I did it here:

http://www.mycncuk.com/forums/showth...inear-bearings-...

But it doesn't really achieve much except for deriving the obvious (space the bearings out as far as you can afford to, and minimise overhang) and showing what I said in my previous post.



Excellent - what did you change it to?

Changed to 20mm supported rails on the long axis - 1100mm, shorter axis (700) 16mm , Z (300) 16mm. Chai seems to be a good guy and altered the order on my request. The primary use for the machine is to cut hardwoods for guitar bodies and the secondary use is for carbon/glass fibre and light (6060) alloy. Aiming for a cut area of the machine of approx 900 x 600. My initial calcs for the maximum static deflection on the long axis, assuming a 30kg carriage of 0.12mm. The supported rail should stiffen this - but I could be wrong.

Thanks for the link - I'll examine this in more detail tonight