Re: Which is the best election for...?

Thanks for you time, experts!

Another questions:

To begin with the start:

Of that size the structures of the table/frame? (Section)
What profile type?
Of what material?
Are the reinforcements convenient?
Screwed or welded?

Thanks a lot.

Thunder2kal


--- In CAD_CAM_EDM_DRO@yahoogroups.com, hannu venermo <hvenermo@...>
wrote:

>
> I ll be glad to help, as far as I can.
> Now finalising (Makeing) a mill ! of almost same size

(1400x2400x400 mm).

> My project has taken over 1000 hours, and 3 years, and 3.000 $.
>
> You should have some basics and well be able to help better -
> How much can you spend ?
>
> How much is your time worth ? - How much speed do you need ?
> How much can you build ? Whats skills/tools do you have ?
> How much time /work can you put in this ?
>
> The best option if you can decide on whether you wish to build the

machine

> or use the machine, and how much you want to build yourself.
>
> If you build most of it,
> can get slides cheaply (Thats a BIG if ?),
> you may get by with about 1000 $.
>
> 0,5 mm is very easy, if you buy slides.
> Look for hiwin (cheapest, good), about 25 mm thickness.
> Theyll cost you over 1000 $ alone.
> (2 blocks on each slide, 2 slides on each axis).
>
> Is this too much ?
>
> Rack/pinion for driving the gantry is about 3-600$, depending.
>
> Pulleys, 100$. You should bore them for your steppers shaft size,

can

> you do this or get it done ?
> Otherwise, add accurate couplers, about 150 $. Look for something

like

> e.g. oldham couplers.
>
> PSU; Can you build this ? It's not very difficult, if you have done

some

> eletronics work/hobby.
> You need about 60-80V DC, 1500 VA.
> There are several schema/drawing available.
>
>
> Linear slides; hiwin, thk, or possibly bishop visecarver rollers

and

> slides.
> I would recommend that you buy them, unless you have acces to and

skills

> in precision metalworking.
> Milling large, accurate slides may be too involved.
> Having said that, I am building my own slides - commercial slides

would

> cost me over 2-3000 $- can't afford it.
>
> Some recommendations follow; no commercial interest.
> Some consensus figures and good providers for your project;
> Dan Mauch, steppers and servos; get steppers, about 400-600 oz-in.
>
> If your budget allows, you may wish to get servos for faster speeds.
> It will make it (slightly) more complex. Maybe 500 $ more overall.
>
> Get/make a PSU of about 60-80 volts, about 20 times your steppers

max

> voltage.
> You max voltage is 80 V with gecko.
>
> Get gecko drives from www.geckodrive.com
>
> Get two optoisolated breakout boards from, e.g. cnc4pc.
>
> Ge some big red emergency stop buttons, some relays to turn off

your

> stuff in an emergency,
> mach3 sw to drive the hw from art fenetry of artfcnc.com,
> rhino3d to design the parts/work, maybe meshcam for 2.5 d stuff.
>
> Gear down about 2:1 or 3:1.
> Use timing belts and pulleys, about 10 mm wide belt.
>
> Get a gas spring to support the head. On a big router like yours,

the

> head will be heavy.
>
> You can make the structure /frame from almost anything.
> I would recommend a welded steel structure. Even wood would work,

and

> some people have used it.
> I am using a mixture of welded, pre-loaded steel structure, with

torsion

> boxes, and concrete for ballast/balance/mass/stiffener.
> My structure weighs over 800 kg.
>
> Aluminium thermal expansion will be greater than you think, and I

would

> recommend against extruded aluminium.
> It will affect your accuracy, over 2800 mm.
>
> Good luck, and welcome to the group.
> Best Hannu
>
> thunder2kal wrote:
> >
> > Hi to all,
> >
> > Can somebody help me?
> >
> > I am to begin the design and the construction of a workshop-made
> > cutting-milling machine of the following dimensions: 2800 x 2000 x
> > 100 mm (9' x 6.5' x .3'), for wood (MDF), with a precision of, at
> > least, 0.5 mm (0.02").
> >
> > I don't have experience in the matter, for what I appeal you so

that

> > suggest me the best alternatives from the point of view of the
> > relationship cost-benefit in the following aspects:
> >
> > In other words: That you would use in each one of the aspects of

the

> > machine?
> >
> > 1) Table/bases/supports
> > 2) Lineal movements/joinings
> > 3) Motors
> > 4) Electronic drivers
> > 5) Software
> > 6) Other aspects that consider important
> >
> > Any advice is very important for me!
> >
> > Thank you in advance.
> >
>