New Build Log ... 2440 X 1220 X 300

**JAZZCNC** · 16-10-2014

No very difficult to build that way and too weak in key areas. Not enough bracing at bottom and the top rails will be very hard to get on same plane.
Look at this and Work along the same lines as this with regards bracing etc but without the adjustable bed if not required with slightly lower sides and you won't go far wrong.

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This machine is in progress and will have 4th axis on the end when it's finished.

Also Why 350mm Z axis travel.? That is quite a lot and if your planning on cutting anything hard you'll get lots of flex and resonance giving a poor finish.

Edit: Opp's Eddy beat me too it.!!. . . or like Eddy's done. . Lol

**Wobblybootie** · 16-10-2014

Why 350mm? Because the whole idea of building the machine is it to perform two tasks, firstly to cut forms from 18mm Birch Ply and then when the forms are assembled by stacking one on top of the other to mill to the final shape. If I cannot have 350 mm of cutting depth I am throwing money away.

I was hoping to be able to store ply sheets ( I buy 10 at a time) under the bed. However with all the triangular bracing everywhere that also appears to be a No No ... Oh well back to the drawing board.

**EddyCurrent** · 16-10-2014

For some reason, after reading you're other thread, I had it in my mind you were laminating at 90 deg. to that shown in the photo.
It's okay milling to 350mm depth but what length cutting tool do you envisage using ? you don't want the spindle crashing into the job.

**JAZZCNC** · 16-10-2014

Ok well in this case then you'll be ok to some degree because the roughing of the forms doesn't require any decent finish and the 3D tool paths will be small step overs so very little tool pressure. Just build the Z axis strong with a good design and you'll be ok.

Regards the Bracing then it will still be possible to store sheets under with a few tweaks here and there so not a big deal.

**Wobblybootie** · 16-10-2014

I'm sure I said fore and aft ... nose to tail anyway now you see the size of the profiles that are cut.

Typical Forums ... lol ... Half say no need for Epoxy on a machine cutting wood ... the other half say it's absolutely necessary.

The Legs didn't come through the tops!! 'capped' they would have been flush ... I hadn't planned running the rails across them anyway. Thinking about it they could have been raised at the back to provide hard stops and mounting limit switches.

**EddyCurrent** · 16-10-2014

Originally Posted by Wobblybootie

Typical Forums ... lol ... Half say no need for Epoxy on a machine cutting wood ... the other half say it's absolutely necessary.

This is for you to decide.

**Wobblybootie** · 16-10-2014

you poured your epoxy in small sections ... how did you get them any more level than the posts they were poured on already were?

**EddyCurrent** · 16-10-2014

Originally Posted by Wobblybootie

you poured your epoxy in small sections ... how did you get them any more level than the posts they were poured on already were?

Sorry I don't understand this, I poured all at the same time in one big section i.e. two rail beams and two bridges.

**JAZZCNC** · 16-10-2014

Originally Posted by Wobblybootie

Typical Forums ... lol ... Half say no need for Epoxy on a machine cutting wood ... the other half say it's absolutely necessary.

Ye because the half that say you do haven't built one before. . .Lol

No doubt you'll read in various threads that I say build in has much adjustabilty as possible. There's a reason for this and I'm sure eddy and those that have built larger machines will agree being able to tweak any error out is a big help when setting up.
Your design with top rail having no adjustabilty is restrictive and rely's completlely on you making sure both rails are on the same plane when welding up or using the Epoxy method and completly relying on it working. This is fine for someone like me with plenty of experience and some nice long accurate straight edges etc but if your tool limited with little experience then believe me you'll be grateful for that adjustabilty.!

**Wobblybootie** · 16-10-2014

Eddy, I saw the little square pours and the 'joints' between the uprights and the rail beams and thought that was where you had laid the epoxy, then I read backwards ...

Okay so epoxy will correct minor differences in the rails and the beams, where else can I build in adjustability I don't include basic adjustment in the feet (they were there to take up floor unevenness)

I can get the rail carrying beams milled top and bottom to give me a sporting chance and have a the lip milled in for the datum edge of the rails.