Hello

[m.marino]

If I understand the drawing correctly, you are looking at this being 2m by 800mm in overall dimensions. That might be a little wide for a single central ballscrew, as racking of the gantry can start to be a problem there. I see a good bit of reinforcement built in, but you might want to look at adding some along the Y axis direction as well to help decrease racking of the frame possibilities. I don't know that seller on ebay as I dealt with Chai of linearmotionbearings also out of China. That is about all I feel able to mention on and I am sure those with more knowledge will pipe up shortly.

Michael

[JoeHarris]

If I understand the drawing correctly, you are looking at this being 2m by 800mm in overall dimensions.
Michael

Thanks for the reply m.marino, the overall dimentions will be about 1500 x 800 - I want to be able to cut quarter sheets of ply - 1220 x 603. Do you think I'm still over-egging it?

[JAZZCNC]

Thanks for the reply m.marino, the overall dimentions will be about 1500 x 800 - I want to be able to cut quarter sheets of ply - 1220 x 603. Do you think I'm still over-egging it?

Joe Micheals correct your on the very edge of being to long and too wide.?

I have built a few very similair machines in the past and actually still have one half built see pic (It's still sat in that same place and has been for over a year, just can't find the time or inclination to finish it.!!)


Your potential problems will be 2 fold.! Potential Racking (In some materials) because of single screw and Whip from length of ballscrew.
To do justice for this kind of machine you will need 10mm pitch screws and the only financially credible option is 16mm Dia and at 1400-1500mm your on the edge of being troubled with whip at high feeds and seen has your mainly going to cut ply wood then you'll want high feeds for best finish, short job times.

If the gantry is built strong then I can tell you from experience that racking isn't an issue at this width in materials like ply wood,MDF with sensible depth of cut(DOC) but can be in harder materials like Aluminium or really hard woods unless low DOC are taken.! . . That said twin screws are far far better in all materials because it really allows you to ramp up the DOC and feedrates and give a much more robust machine. . . They are my prefered choice every time if budget allows.

If your needs are just ply wood then I'm confident you'll be ok on the racking front so long has your not expecting to cut 19mm in 1 pass. .!!


Regards Ballscrews etc then I'd recommend Chai at Linearmotionbearings on Ebay you won't find a better guy and 110% trust worthy, certainly worth paying a few quid more just for peace of mind your stuff will arrive(usually within 10days) and if wrong or bust it will get sorted.!!

[Chris J]

(It's still sat in that same place and has been for over a year, just can't find the time or inclination to finish it.!!)

Looks great

[Chris J]

If anybody is replying specifically to me I have started a build thread here so maybe a reply there might be best - cheers