Aluminum profile and alu plate 1500mm x 600mm x 150mm working area, first cnc.

[pierantoine]

i will take the steel frame route.
there is a useful post where i've seen nice frames from Dean and Boyan... i've made a mix :-)



I've seen a post where Dean suggest 2 fixed ends for the ball screw
http://www.mycncuk.com/threads/8490-...x750x200/page3
"To give you an idea I recently built a Slaved axis 4x4 router with 20mm Dia 10mm pitch screws 1700mm length Fixed/Fixed ends with 2 x 3.1Nm steppers"..

the 2 beams supporting the rails can be slightly not parralels so an adjustment for fixed ends must be adjustable.
if you have made something like this i'm really interested.. thanks

[pierantoine]

Thanks to every one after many hours of reading here is what I will make.
Here is the final version before starting the build and ordering the parts...

the green frame could be made on a bench before the red / yellow...

adjustable mounting of the ends...



the green plate is 15mm ground plate maybe. i'have found 20mm but is not ground...




between collet and frame (without bed)
218mm Z up an 68 mm Z Down.

For the plates 40, 50, 51 supporting the carriage would it be better to have 20mm not ground or 15mm ground ?


Do you have any comments before I start the build ?
Many thanks..

[Lee Roberts]

For the plates 40, 50, 51 supporting the carriage would it be better to have 20mm not ground or 15mm ground ?


Do you have any comments before I start the build ?
Many thanks..

15 Ground, if you can't machine the mating surfaces.

Orange plate not needed, punch down from plate 51 to the nut (see pic example).



Or, if you really want to create a box, punch down from plate 51 to plate XX but make orange plate an X shape, locate nut in the center of the X (less material than current orange plate).



.Me

[pierantoine]

last version with 80x120 aluminium profile.


I have shorten the long axis to improve acceleration / whipping

i've read the forum and it seems that for 1500mm rm1610 could be a better choice than 2010 for acceleration reasons. do you agree ?

[JAZZCNC]

i've read the forum and it seems that for 1500mm rm1610 could be a better choice than 2010 for acceleration reasons. do you agree ?

Yes for acceleration reasons but at that length your still high chance of whip with 16mm screw. And why would you need Higher acceleration than 20mm could provide.?
At this length 20mm is better suited and to improve things more go with 20mm pitch and use 2:1 ratio on the pulleys. Also have Fixed bearings at both ends.
This gives the advantage of lower screw speed and higher torque. The Fixed bearings make everything that little bit stiffer.

[pierantoine]

Hello Dean ! thanks for your answer, yes both fixed and 2:1 with htd5 15mm was planned with ali pulleys 2 grubscrews and i've seen that you also advises that using Angular Contact Bearing from Fred worth the price so i'll do like that..

[JAZZCNC]

Hello Dean ! thanks for your answer, yes both fixed and 2:1 with htd5 15mm was planned with ali pulleys 2 grubscrews and i've seen that you also advises that using Angular Contact Bearing from Fred worth the price so i'll do like that..

Would only use 2:1 ratio with 20mm pitch. If done with 10mm pitch the speed will be too low for router.