Smiler's Build

[irving2008]

Thanks Jeff ill add that link to the links database now.

Yea i may just give the pvc a go for the little mini mill i wanted to build, ali costing more money ! maybe once i get my rockcliff up and running maybe then ill use ali and get the rockcliff to machine it.

Nice machine Jeff congrats !

I would do a little more research on PVC v Ally or MDF...

Here's some data (MDF/PVC/Alu):

Tensile strength: 0.3/58/300 MPa
Youngs Modulus: 3.6/3/69 GPa
Density: .73/1.44/2.7 kg/m3

The MDF is half the weight and slightly more rigid against bending than PVC but will delaminate far quicker. MDF is also far cheaper than PVC (about 1/25).

Solid aluminium is 20 times more rigid than either MDF or PVC but weighs more (2 x PVC, 5 x MDF) but then it could be 1/5 the thickness of MDF but still 4 times more rigid.

So PVC's main advantage is in areas where the MDF is likely to delaminate under stress... eg where it has to be end-fixed or there is a strong perpendicular force retained purely by the MDF (not bolted through). Its not an obvious replacement in all areas.

The other main advantage of PVC compared to MDF is that it is available in a range of thicknesses up to 50mm.

I would potentially use PVC for:

• The table, where you want to machine the surface flat and avoid flaking.
• The gantry sides where I could use 40mm thick PVC and get twice the rigidity of MDF (then again I could use 2 pieces MDF bolted/glued together to get the same result at 1/2 the weight and 1/10 the cost)