Vertical fixed gantry. Design & build. (Steel/epoxy)

[Greeny]

Well must say That's an ambitious first machine.?

Yes, it has kind of got out of control!
Should be fun though, until it starts going pear shaped.

Thanks for the advice on chip protection/clearing and raising/tilting.I hadn't really given either a great deal of thought.
Will ponder more on those.

With the Gantry raising and lowering in place of a typical Z axis then I'd connect the screws with timing belt rather than using twin motors, you'll keep screw sync much better.

I am definitely thinking about one motor for both screws. It seems both the simplest and best way of syncing the screws.
The gap between the screws is ~1770mm. Is this something to worry about with belts?
Is it possible/feasable to have a central motor driving two pulley wheels (one for each screw) so each belt is half the length.(each belt would need a tensioner)
quick & dirty sketchup

Oh and why are those screws on the bed so far out.?

They are slapped on there as i'm unsure about pulley system & the layout for pulley wheels.
There is quite a bit of wiggle room so i should be able to finalise their position soon.

Thanks for the comments an advice
Cheers
Greeny

[JAZZCNC]

Oh before I forget your not from Yorkshire are you.? My best mate at school was called Paul Green but he moved away.!

I am definitely thinking about one motor for both screws. It seems both the simplest and best way of syncing the screws.
The gap between the screws is ~1770mm. Is this something to worry about with belts?

No except you'll have to have it made for you, it won't be something you find on the shelf. Most decent bearing/belt suppliers will get you one made. If at the time you have trouble drop me an email and I'll put you intouch with someone who will.

Is it possible/feasable to have a central motor driving two pulley wheels (one for each screw) so each belt is half the length.(each belt would need a tensioner)
quick & dirty sketchup

Yes and infact my first effort with belts was done something like that but in a V shape.

[Greeny]

Oh before I forget your not from Yorkshire are you.? My best mate at school was called Paul Green but he moved away.!

Strangely I am!
But Whitby in North Yorkshire. I've never moved, so we must be different people. (I will update me profile)


Regarding the belts, that's exactly what i meant. Cheers.
Which would you recommend?
Single long belt, or two shorter ones as per your picture.
Or is it 6 of one & half dozen of the other?

Cheers
Greeny

[JAZZCNC]

Strangely I am!
But Whitby in North Yorkshire. I've never moved, so we must be different people. (I will update me profile)

Ah was just up road few a weeks ago at friends in RHB.

Regarding the belts, that's exactly what i meant. Cheers.
Which would you recommend?
Single long belt, or two shorter ones as per your picture.
Or is it 6 of one & half dozen of the other?

Well seen has I went with the long version I'd have to say that but really there's nothing in it and I only went with long because it was easier to make covers (Which never got made) . . .Oh there's a tip for you DONT EVEN THINK ABOUT turning machine on until you have finished all you planned to do, you'll never do another thing to it again for least 5yrs if you don't.!!

[Greeny]

Ah was just up road few a weeks ago at friends in RHB.!

A gem of the NE coast. Was in Dolphin for a pint or two just last week!

Thanks for the info on belts, and the warning about finishing before firing up. That definitely applies to me!

I have been thinking about the advice given so far and am now thinking about toning in down a bit.
Here is a new draft, with quite a smaller footprint, that is simpler, and should be a lot easier to build. As well as cheaper for Rails/Screws etc. which i still have to buy.
Have added M20 ball feet so i can adjust the lean angle.

Cheers
Greeny