Let the fun begin !!! ???

[PAULRO]

hi Jazz, i'm looking for dimensions for bearing blocks for 20 mm ballscrews, could you point me in the direction? i have been reading that fixed blocks at both ends is the best option, ya? i have a frame sketched and am starting into the y axis gantry design

[JAZZCNC]

Here you go this should help.

[PAULRO]

At last i have an opportunity to get some images of the intended build posted for comment. i have read a lot of material on this forum and tried to include as much advice as possible . i haven't purchased any materials yet even though i'm itching to get started , but taking the advice given to other potential builders from Jazz, Jonathan , among others, i will build the frame first and then once i'm sure of key dims. i will take on the mechanical purchases and build. the gantry images are posted as a reference to my intended build but as always i'm open to suggestions.

the frame size should take a half a standard sheet ( 1220 x 1220 ) built from 80 x 80 box section. 5 mm wall for the top rails and 3 mm for the rest. the adjustable bed ( yellow) will be held in place by graduated 50 mm x 6 mm angle ( green) secured to the frames uprights. the stand alone box section ( blue ) is detachable to allow space for a fourth axis , eventually!!

i have a choice of extrusion for the gantry ( length 1610 mm ) either 100 x 50 , 4.18 kg/m, 120 x 40 , 4.35 kg /m or 120 x 40 , 6.8 kg /m .

the linear slides, 20 mm hiwins , ballscrews 16 mm and aluminum plate for gantry , 20 mm . i haven't any motor specs yet so i didn't finish the z axis assembly . I might use 20 mm linear slides on the z axis ( off cuts from the 2m x rails ) or just purchase 15 mm rails. i will use epoxy to create a plane for both x axis and a permanent bridge for this and the x axis motor to belt drive the twin ball screws, OR use separate motors for each x axis ballscrew. all to be decided with the advice from the experienced builders here, hopefully!!!! i'm also looking for some motor dims, nema 23 , 3nm. they seem to be the weapons of choice for what i'm about to take on , so if any one can point me in a direction for a reputable supplier that has dims i can use to finish the z axis dwgs i would appreciate it. cheers Paulro.

[EddyCurrent]

Maybe you could incorporate into the fourth axis space something to allow this; http://www.mycncuk.com/threads/7688-...9686#post59686

[PAULRO]

ya , that is a great idea. that's what's great about this site , ideas get bounced around and seeds are sown. i've been on this site for the last year getting as much info. as possible and getting cash together at the same time for a router build. can't wait to get stuck in. i'm confident of the mechanical side of the build and have some electrical experience but will need help to get me through the potential pitfalls i think i will find myself in. hopefully i can rely on the experience of the previous builders on this forum.

[EddyCurrent]

The gantry ends look quite substantial but I'm not sure how well the structure will resist twist at the centre, here's some info relating to that subject.
Machine stiffness; http://www.mycncuk.com/threads/7155-...4942#post54942
Stiffness calculator; http://www.mycncuk.com/threads/2214-...5791#post15791

[JAZZCNC]

Hi Paulro,

Got your PM.

Yes the gantry will be fine for your use as a wood router and yes I've built one about same size using same design so know it works. What you doing with the ends of gantry and how you connecting to ballscrews.? Drawing with gantry mated to frame would be good to see.

Regards Y axis ballscrew mount then you'll need to brace the drop bracket more.