Gantry plates for avid drive

[Lee Roberts]

The seller dont answer me at all, so i will order new alumium profiles from Tuli and racks and drive from Avid CNC, then i can measure the size i want and where the hole should be located i dont know the fitting for avid drive where the spring hole and the bolt hole should be if someone else dont have it and can see.

Ok so you are going to order the Avid CNC drive system, that's good we can make a CAD of the plates that way ?

I have order http://shop.cncdrive.com/index.php?productID=1098 this control box and 8nm closed loop stepper motors from them, really hope its a good upgrade from my obsolete thing that was with the machine.

Nice :) that should save you allot of time, 8nm should also be good, maybe more than you need (3Nm is quite ok) but ok.

what is best solution for stability to have linear on top of alu profile and use the idea from ebay link on Y and A Axis or is it better to have the linear exactly as Avid CNC solution on the side gantrys togheter with the drive and rack on the alu plate?

Absolutely go with linear rail on top of ali profile, not for stability but for an easy life when you need to make everything on the same plane and aligned perfect to each other, the side mount for linear rail is just harder and more time consuming to get really nicely setup. On top you will find it easier for alignment and more so making the adjustments for this work/ procedure.

You know about linear rail alignment and setting up right?

I would put the rack and drive mech on the side yes, it works well and keeps everything away from the chips and dust ect, you should factor a cover for this stuff maybe.

Then from my attached pictures when i look at it it looks like a stable idea to have linear on top and front instead of both linear attached on only front side, or do i think wrong here?

I will say it doesn't matter greatly, however at some level 1 rail on top and 1 rail on the front is better, again it becomes about alignment and setting up really, my advise is to put the front rail first at the bottom of the front so it is close to the cutting as possible, when you have the rail in place, you can use it to help do the alignment for rail #2 on the top, use the whole Z axis assembly to guide the "lose" rail on top, to the place where it will naturally like to live. After you can then use DTI and spend the time to do the highly accurate alignment of the rail etc.

Really the profiled linear guideway and bearing of this type dose a great job with either rail positioning/location, but generally you should try and keep them as close to the cutting forces as feasibly possible, making sure of course that they will be before the leadscrew or to say it best "the drive mechanism", you must do your best to stop the forces from cutting etc, from reaching the drive mechanism.

but it should be a more stable solution to have it as i have it now and its it on the ebay link?

Again, absolutely go with this ebay design (in the pic below), no design should ever have the gantry sides so that they are like "stilts", its just so obvious to look at, that it is a bad design!...then you see the designers try and make good and overcome the instability/rigidity by now putting extra plates, corner brackets and an effort to "brace" everything together etc...

It is really quite disappointing to see, especially when you also see how popular the said machine becomes with the community...sure it works and you can cut some stuff but that doesn't make it right...



Moving on...

Your English is fine I can understand you, I didnt take ANY Swedish lessons but I do have a google