How should I do a spoil board

[timjet]

I’ve got my CNC table built with a 3/4" thick 48" x 52" MDF top for my new MK2 30 x 30. I’ve never used a CNC before so everything is new to me.
So what do you folks recommend for a spoil board. I don’t want to replace the MDF top after each mistake or cut though so I want to put something on top of the MDF.
From my limited research there seem to be a couple of options.
Tracks with 3/4" MDF cut into 3-4" strips with the tracks mounted between the MDF strips.
Another option is to place another 3/4" MDF on top of the existing one and drill threaded inserts or T-nuts every 3-4" into the entire surface.
TIA for any suggestions.

[Bill]

@timjet I started with the t-nut style board, alot of work & hardware for something one typically scars up. You can resurface however just above the height of the t-nuts. I eventually went with 4" strips & aluminum T Tracks and have been pleased, easy to replace if damaged, great hold down options. Time of use and a good digital micrometer make a world of difference plus using the surface to zero rater than material,
.

[_Michael]

I use T-Track as well but mine run from side to side instead of front to back. Has worked well for me, never tried the ‘sea of holes’ because I tried T-Track first and never looked back.

@Bill

plus using the surface to zero rater than material

In the post linked below you will find a link to a short video that will explain what Bill is talking about here. It’s a method to minimize spoil board damage so you don’t have to replace it as often. It might seem strange at first, especially being new, but you do have to learn how to set the origin point or zero your machine so I would suggest that if that video is confusing to watch it again after you have done a job or two with your machine.

Replacing my Spoil board 30X30

@gwilki linked this video awhile back and it helped me to not ruin my spoil board. Basically as the video says if your thickness is 19mm you set the bit so it just touches the spoil board and then in gSender you click on the Z number and enter -19mm and hit enter. Then when you cut through it will either cut all the way through or just leave like a sheet of paper thickness to clean up.

[timjet]

Bill, thanks for that info. I see in your picture you have a corner set presumably at X0, Y0 that is adjustable via your T tracks. I’m wondering why you didn’t permanently fix those corners and allow the CNC to trim them exactly at 0-0. It looks to me that even if those corners are exactly square as you show with the metal square they might not necessarily be square to the CNC machine. I’m a newbie so I might not be making a lot of sense.

Michael, thanks for that video link. I will keep that in mind when cutting out projects.

Also do you guys suggest mounting the MK2 on the table or the spoil board? I see Mike has his on the table.

[norm]

3/4 mdf with t -Track5 inchs on center worked great

[_Michael]

@timjet

Also do you guys suggest mounting the MK2 on the table or the spoil board? I see Mike has his on the table.

@gwilki recently shared his view on this subject and I think he sums up the pros and cons nicely.

Table setup for MK2

@El_Cheapo Welcome back, Neil. There are pros and cons to both installations. I chose to mount the LM feet on slats of 3/4" MDF so that I get the most Z travel possible. The initial big plus for me was squaring my LM. The MDF slats have slots in them. I used 1/4" bolts up from my table base and through those slots. When I was squaring my LM, it was a simple matter to loosen the bolts, nudge the slat a bit and tighten it back down. This made it very easy to move the Y gantries a very small amo…

It hasn’t been a problem for me with the machine mounted to the table but if I was starting over I would do it the way Grant did his, for the reasons that he mentions.

[timjet]

Thanks Michael, I will mount mine on the spoil board.

[Bill]

@timjet Both the X&Y are adjutable and movable, The adjustable boards are great when replicating identical jobs, and reduces the amount of clamps needed. I typically chuck up an old 1/4" end mill and tram the machine to adjust, once set they align perfect with the machine. I also have my longmill mounteed up on strips of 3/4" MDF to zero or compensate for the 3/4" spoilboard setup I have. After recently trying to cut more than 3" I’m adding another strip under the feet.

[Bill]

@timjet I suggest not mounting on the spoil board, if you do and need to change out the spoil board you’ll need to set up and align the machine again. I have the feet on 4" or so strips of mdf.

[timjet]

Thanks Bill, I will do as you suggest.

[gwilki]

@timjet I’ve moved your topic to the Machine Help/Assembly category, Tim. I believe that members with the same question may be able to find it here more easily.

[alaska42]

This is how I did mine. You may want to consider a fence, very handy to have.
Longmill Spoilboard

[Tpoole1988]

Awesome setup, did you build that entire table or modify a top and bottom to an existing piece?