MDF Question

[studysession]

I put my big DYI machine back together. It's been sitting in parts ever since I moved at the beginning of the year. I put a MDF table top and then planed it using a 3/4 inch bit on my router / spindle. Now I have a few questions for the pro's.

How do I mount my work to the table?
I have seen some posts about gluing your work to the table. Does that make the table uneven with the glue residue over time or does it build up inj any way?
Should I put a cote of polyurethane over the MDF at all? Will that warp it after spending all that time planing it?
Or should I paint it with white kilz or something like that?

Anyway - I am at the part where I can actually cut something and need some advice before I screw things up. Many thanks in advance.

SS

[danmst3k]

I've built a MDF CNC router as well but I haven't even moved anything yet (still waiting for my PC from ebay to arrive). My table top is 3/4" MDF and it's 21 x 36 inches. I purchased some t-track from grizzly.com (actually through amazon.com) and got 4 lengths of 3 foot track. It's the typical 3/4" wide and 3/8" deep and they are only about 8 bucks each. You have to drill your own holes and there's no screws but that's alright. Also, rockler.com is having a sale on 4' t-track and it comes with t-bolts and knobs for only 15 bucks. Don't know about sealing MDF though, I think I might paint mine at some point. The way I designed my mill is I built a sturdy (torsion box type) table and then put another layer of MDF over that as a sacrificial surface. If I have to change it at some point I just have to unscrew the t-track and route slots in a new piece and slap it back on top. Hope this helps.

Dan

P.S. what endmills are you using. This is an area I'm having a hard time figuring out. I'm using a lamenet trimmer with a 1/4" collet and I was wondering if there is a set of endmills with a 1/4" shank. Maybe an assortment of ball, flat etc.?

[studysession]

I am using a Porter Cable trim router with 1/4 inch collet as well. Right now I have quite a number of wood router bits. Not decided on end mills yet.

Thanks

[studysession]

Right or wrong this is what I did.

Bolts down in 4 corners 1 3/4 inch MDF 2' x 4'. Glues another right on top of it.
Planed it with my 3/4 bit.
Then put a 1/2 thick 2' x 4' MDF on top of that and bolted it down to the bottom 2 pieces. Then put quick drying polyurethane over it to protect the top.

Now see what happens.

[studysession]

I want to scream. I had some problems with my machine on the X axis. So took it apart and put it back together - had to redistribute the weight more. Anyway now with that fixed -

The cutting area which took FOREVER to plane off and make even with the router is no longer even with the router and now have to do it again. AAAUUGGHH!@

Attached is a picture of my machine.