New build help needed

[komatias]

Oh dear, I am not the only Greek on here any more. Vaggo, looking forward to seeing your cutting machine too.

[arg123]

Kingcreaky thank you for the files.

Looks really nice. Is it 3100mm in the long axis? Are you bolting the plates to the vertical frame first and then weld the cross members in place or have them made before with the 2 plates attached and then bolt them to the vertical frames? Can I pre-drill plates and side members using a jig in a bench drill then tap then start building the frames or I will be way too off?

Being new to CAD I spend the last 3 days trying o design a preliminary plan of the base. My main concern was to be able to design it parametrically so I can change most of it on the fly without having to redesign it again. So far it works well even though the design structure is like spaghetti code.

The base steel tubing is 60x 60 x 5 and the lower grid is 60 x 40 x 3.
The top right and left tubing would be bolted to the base for adjustment purposes if that is an extra benefit.Then epoxy leveling .
Any suggestions where to source the Hiwin rails? CAD files for them?



Thank you all

[Rufe0]

Any particular reason your using so many cross members? Just out of interest how far are they separated? Its certainly not a bad thing, the more the merrier I would think, however I think it would be significantly stronger in terms of deflection to have fewer cross members that where triangulated to the bottom rails rather than more with no triangulation. Having more would be beneficial though because it would support the sheet more evenly along its length.

[arg123]

They are 311mm apart when the base is 2800 x 1650.I was thinking of having the lower grid of the base free for storing ply .

[komatias]

Argyri,

Looking good!

The best place to get the Hiwin CAD models is http://www.hiwin.de/en/CAD_Configurator.html

Most cost effective way to get the rails and carriages is to go east. I would suggest that you get carriages with preload so they do not have any slop, it adds a bit to the friction but worth the extra effort.

In order to account for distortion etc I would suggest you build, level and then drill. A hand drill with good bits and a drilling jig like you describe is good as long as you make provision to straighten the rails afterwards. Have a look at installation instructions from HIWIN which is similar to this NSK one for ideas on mechanisms to align and adjust for straightness and squareness, if you haven't already done so.

You could have the top sections on bolts but what would be the benefit if you epoxy level and drill afterwards? From our conversation it seemed that you were not thinking of moving the machine around so stripping it down is not needed. I would have thought that, should you crash the machine, you would need to readjust everything including the rails. In a rigid system, you will potentially only need to readjust the rails.

Regards

George

[Rufe0]

Yeah that seems reasonable.

[JAZZCNC]

I see a few things I would change but rather than put into words it's easier to show you. Most Should be obvious but ask if not sure.

The reason for top rail being longer at each is to recover some wasted bed space plus makes machine shorter. Also allows gantry to ride past the end so can use end of machine for standing boards upright or fitting 4th axis across end if required. Long overhang would be rear short would be front.

[arg123]

Dean,
Thank you very much for your help I really appreciated.
Smart way to increase the cutting area and add future use(4th axis)

Few questions and I think I am good to go.

Steel tubing for the whole base 60 x 60 x 5 ? Do you agree on that?

Length of the bed 2600 + 100 short overhang + 300 long overhang = 3000 total would that be o.k? Do the overhangs need to be braced?

What are the spacing of the cross members and the top rail supports in your drawings? No dimensions so I can't calculate.

Has anyone joined hiwin rails lengthwise let's say 1500 + 1500 to achieve 3000mm length. Is it doable for the home builder? ordering from BST automation 3000mm rails will make shipping cost way up.

Hopefully I will be start building in the beginning of January.

[JAZZCNC]

Few questions and I think I am good to go.

Steel tubing for the whole base 60 x 60 x 5 ? Do you agree on that?

Well kind of but only has a minimum. I'd be more inclined to go with 80x80x5 on such large machine but 60x60 will work fine.

Length of the bed 2600 + 100 short overhang + 300 long overhang = 3000 total would that be o.k? Do the overhangs need to be braced?

What are the spacing of the cross members and the top rail supports in your drawings? No dimensions so I can't calculate.

Dimensions will depend on your needs and gantry etc. I only drew this frame to show you and save explaining via text.
That said the dimensions I used where based on previous machines I've designed and are very close to those you mention.
From memory the short overhang was 150mm and the large overhang is the same length has the gantry width. Bracing on large overhang depends on gantry width but if more than 300mm then yes brace it.

Here's a 4x4 machine built using similair frame design but with adjustable height bed. Frame is 60x60x5 box.

Has anyone joined hiwin rails lengthwise let's say 1500 + 1500 to achieve 3000mm length. Is it doable for the home builder? ordering from BST automation 3000mm rails will make shipping cost way up.

Yes it's commonly done on really long machines but does need careful fitting. Thou If possible I'd avoid doing it.