JBEC router system UNDER THE BONNET

[StoneyCNC]

Further to the post on the new JBEC CNC router system availabe in the UK
http://www.mycncuk.com/forums/manufa...ilable-uk.html

The following is some information for those interested in under the bonnet inspections. Apologies this has taken longer than expected. Not enough hours in the day and I wanted to do it right and be as comprehesive as possible in the hope that on day in the next decade we get the JAZZCNC seal of approval :)

Right - here goes...

So the pictures are all from our JBEC 604012 model shown below in Figure 1.


Figure 1. - JBEC 604012

Figure 2. shows the main components of the main drive system used to traverse the main gantry. The design is based on two rails mounted on the opposing faces of the main machine bed frame. Two slide rails, each consisting of two rolling element bearings (discussed further below) sit on the two rails and provide the required stiffness in all directions except the direction of motion where the slide moves freely with minimal friction.


Figure 2. Gantry structure design overview


Figure 3 shows the top slide rail mounted and bolted to the main side aluminium panel. A second inside panel covers the assembly shown and increased the torsional stiffness of the frame as it is shown. Shown also is the ballscrew encapsulation at the opposite side to the motor.


Figure 3. View of the slide rail mounted on the bed.

Figure 4, shows the mechanism used to transfer the drive from the ballscrew carriage to the bottom slide rail. Note the 5 bolts in the mouing system connected to the slide rail. The 4 outside bolts fasten the aluminium panel to the slide for the drive transfer. The middle bolt is used to tune the gantry position - and is discussed further below.


Figure 4. Bottom rail and drive system assembly

Further to Figures 3 and 4, Figure 5 shows the linear slide disconnected from the slide rail. Shown are the rolling elements used to interface with the slide rail. Note also the tuning block connected with the tuning bolt shown in Figure 4.


Figure 5. Image shows the exposed rolling elements

Figures 6(a) and (b) show the linear slides composition with the rolling element shown. The rolling elements are supported on both sides and have two internal bearings. Not also the trough in the rolling element that allows some leeway for swarf and other possible contamination getting into the drive system.


Figure 6 (a). Top linear slide rolling elements

Figure 6 (b). Showing how the slide system assembles together.


Figure 7(b) shows the gantry side aluminium panel and shows the two bolts fastened to the tuning block as shown in Figure 5 and Figure 7(a). The 4 other holes shown are slotted to allow the tuning bolt to be used to adjust the slide setup. Once tuned and adjusted the holes are fastened and the gantry is ready for final assembly. The system is modular and therefore easy to change, service and tune long term. The result is a very stiff structure that provides excellent support in all directions apart from the direction of motion where linear almost frictionless travel can occur


Figure 7 (a). Bottom slide assembly setup

Figure 7 (b). Side panel for drive tuning

Figure 8 shows the extra aluminium side brace installed to provide extra stiffness through from the ball-screws into the gantry tower.


Figure 8. Stiffening plate

Figure 9 shows the two ballscrews used to drive the gantry structure. Both the side pillars therefore have their own drive mechanism from each of the two ballscrew carriages. Figure 10 shows the cable management under the machine bed used to transfer the drive motors and spindle cables up into the gantry tower structure. Figure 11 shows the drive distribution from the stepper motors to the two ballscrew pulleys driving the two Y axis ballscrews.


Figure 9. Dual ballscrew drive

Figure 10. Cable management under machine bed

Figure 11. Belt drive to the two ballscrew pulleys.

Figure 12 shows an overall view of the Z axis slide and drive mechanism. As shown the upper and lower z axis guides are spaced apart such that they are located in the same locations on the gantry as where the X axis slide mechanism mounts on the main X axis slide rails. This is further illustrated in Figures 13 and 14. Figure 14 shows how the ballscrew drive will transfer force directly at the same location as the main X axis carriage system, and from there directly into the X axis guide system.


Figure 12. View of the X axis mechanism fully assembled

Figure 13. Close up of the left hand side upper prismatic guide

Figure 14. shows how the process forces are translated into the gantry tower structure.

If ever you are put in front of a CNC router system you are about to part cash with. I would ask every customer to look at this aspect of a machine as it plays a core role in the machine performance. If you grab the spindle structure (not too hard in case you break it before you've bought it :) ) and put some pressure on the structure in all directions and see how it performs. What your doing essentially is simulating a cutting process where you are putting forces on the machine. The level of "play and delfection" will dictate the performance.

You will pull the machine off the table before you bend and flex the gantry structure with any significance on this platform.


Figures 15 and 16 shows the control electronics. She runs on a 48V PSU matched to the oriental motors specs running each of the three axes. There is a BOB for the LPT logic distribution from the PC side and there is a 12V relay board for the user interface buttons on the machine control panel. Figure 17 shows the innerds of the machine control panel. The latched start, stop, Estop and spindle on/off override switch are all operating safely on 24V running back to the relay card. 230V AC comes in and up through the machine for the spindle only and does not come through the control panel.


Figure 15. System electronics

Figure 16. AC in and LPT connection and 4th axis connection.

Figure 17. Control panel work


Figure 18 shows our USB controller that we have adopted as standard thanks to CNC drive electronics. We now offer a range of CNC drive electronics with more information coming soon.

Figure 18. USB machine control

High res image link here JBE CNC router design - a set on Flickr


JAZZ - that okay? Not to much waffle I hope. I've tried to keep it clear and concise?