My longmill mk3 30x30 is on order and I can wait for September to arrive
I am debating on the spoilboard and how I want to do itā¦ was thinking just using screws and 2sided tape, then thought about using fence and then ok what corner to use then thought everyone uses t-tracks and well I want to have a spoilboard with the grid engraved on it so I know the exact placement of my materialsā¦ ok now here is the kickerā¦ my enclosure is being built below my workstation due to limited space and watching @BitnerBuilt and his ideas along with others on YouTube, Iāve gone ahead and saved space by building it into the lower part of my workstation, honestly it was the only way I could allocate enough space to purchase a 30x30 cnc and my little desktop isnāt enoughā¦ Thoughts on wasteboard/spoilboards and clamping would be great and last but not leastā¦ I want to mount my cnc on 3/4 inch MDF on top of the Torsion Boxā¦ would you have 3/4 MDF then 3/4 MDF spoilboard on top of that or would you cut the middle out so your spoilboard is replaceable without having to unmount the cnc machine? I am thinking about this as with cutting the middle out of the same 3/4 MDF as machine mounted to, would that take away from the structure and stability of the machineā¦
@Derekh1979 I watched bitnerbuildās video months ago and frankly I thought that he was nuts. I simply could not see myself on my hands and knees on a cement floor sticking my upper body into the CNC enclosure to position material and hold down clamps. Same issue with bit changes. I made sure that I could accommodate my 30 x 30 LM on a 4 x 4 table before I bought it. It takes a lot of space from my small basement shop, but I donāt regret it at all.
I have my rails mounted on two 3/4" mdf slats that, in turn sit on the table top. The spoilboard is completely separate. The last thing that I want to need to do is unfasten the gantry feet to replace my spoilboard. There is no effect at all on the stability of the structure, IMHO. The slats that the rails are mounted to are bolted to the table top with 1/4" bolts running through slots in the slats. That made it very simple to ensure the machine was completely square before I fully tightened the bolts.
All this said, there is no wrong way to do this. You can read the details of many setups here and take bits from each one of them to suit your needs. Be sure to post pics and descriptions of your final setup.
@gwilki Thanks for the feedback truly appreciate it. Yeah going to be a bit of a pain for clamping and bit changes but I donāt feel I will regret the purchase. If worse comes to worse I remove it from the bottom and rebuild the enclosure on the top and figure something else out for a workstation area. The 3/4 inch MDF slates your 30x30 is mounted to how wide are they? Also can you give me some feedback and thoughts on style of spoilboardsā¦ If using T-tracks what are the slat widths in between your t-tracks?
@Derekh1979 The slats that the rails are mounted to are about 4 1/2". There is no magic here. I used what I had. The inside edge of the slats is flush with the inside of the feet.
I use 6 of the Sienci t-tracks as I like the idea that I can use standard 1/4x20 hex head bolts rather than t-bolts. I simply put one track running along each Y rail, just outside of the outer limit of the X travel, then equally spaced the others. Again, your intended use of the machine may well mean that you space them differently.
I use MDF for my spoilboard. I donāt bother to seal it, or muck with it any other way. Itās reasonably stable - note the āreasonablyā - and mills well. For smaller projects, I frequently use a smaller secondary spoilboard clamped to the main one. It helps to limit how often I need to re-surface the main spoilboard. I canāt remember that last time I actually surfaced the main one. Using the smaller ones and correctly setting my cut out toolpaths means that the main one lasts a very long time without re-surfacing. Take a look at what @Spamming_Eddie does for his spoilboard alternative.
To secure my material, I use wooden hold down clamps, blue tape and CA glue, double-sided tape, screws and vacuum pucks - whatever suits the job.
I will repeat, though, that my way is not only not the right or wrong way, nor maybe not even the best way. I do what works for me.
There are many threads on here on how users set up their machines and how they hold down their project material. You can learn something from any and all of them.
Ok folks I was having a torsion box professionally made but this guy has done nothing but delayed the process I am thinking of canceling the project. Is a torsion box needed for a 30x30 longmill or would double 3/4 MDF be enough? I have a very stable and heavy duty cross pattern structure underneath. THOUGHS?
Iāll stick my neck out and say that a torsion box is definitely not needed. Iām not saying that itās a bad idea. My bed is a piece of 3/4" mdf, on top of which I have my 3/4" mdf spoilboard. My table structure is made up of milled 2x4ās. They are flat, straight and square. In the several years that I have owned the LM, I have had no rigidity or sagging issues at all.
@Derekh1979 If you are asking me, it has been for several years. IMHO, the key here is not how thick or how many sheets, or torsion box or no torsion box. The key is how is the table top supported. A torsion box letās you get away with less underneath support since its support is largely built in. I chose not to go that way. Instead, I went with a well supported single sheet of 3/4" MDF. It cannot sag because the supporting structure will not let it sag. One of the benefits of this over a torsion box is that I have been able to cut a piece away to accommodate a vertical clamping fixture. I could not do that as easily with a torsion box. I have also lowered the mounting base for the Vortex to allow me to mount larger pieces. Again, that would have been more difficult with a torsion box.
Since you donāt seem to have the equipment and maybe the ability to construct a torsion box, you may want to stick with a simpler table. I have all the machines and the ability to make torsion box if I want to. So far, I have not seen the need.
I was summoned to this topic and can only say that I do not use a classic spoilboard, but use individual spoil strips that are fast to surface, easy to replace and cheap to reproduce.
@Spamming_Eddie very interesting and interestedā¦ BUT now you have more ideas in my head to choose from lolā¦
So you use these as a fence and can add clamps to the fences if neededā¦ hmmmmm guessing you use thin mdf under the project for those times you cut through the project?
Nope, the strips are the spoil boards, the project rests on them. When I use cut through toolpath, I zero on one of the strips so they donāt get hurt too much. This section is my tiling jig but they integrate with the rest of the strips on the machine for horizontal milling projects too.
I built a torsion box as well. My box serves only the purpose of being a table. On top of that, I have two 3/4 MDF strips and the Y rails are screwed to that (ensures I donāt lose height). The spoil board lives in between those and is made up of 6" wide 3/4 MDF strips separated by T track and with a T track at the foot. There was a plan for treaded inserts. I have them, but havenāt installed any yet. T has been mostly doing the trick. When I do the I may either set them into the spoil board or set them into the underlying table and design my spoil board with holes providing access to them. This would give me more room for surfacing the spoil board before I hit an insert and also makes it less work to replace the spoil board slats because I donāt need to swap inserts.
I added a grid pattern. It serves the dual purpose of aligning things but I also use it to periodically check the squareness of my machine. I carefully calibrated the CNC for squareness before cutting the grid. Then once the grid was cut, I could rely on that to place a v bit at one end of an x-axis line and then at the other to ensure that I was tracking squarely.
I saw a recommendation for āspoil stripsā. I wouldnāt personally use that because I have had projects of v-carving into two-colour plastic and I need my surface to be dead flat. If you really donāt want to spoil a spoil board, Iāve seen others use an additional sheet then attach to the spoil board and then carve on top of that. If I needed dead level, I could surface just that spoil sheet before attaching my material to it.
Thanks so much for your feedback. Greatly appreciate it. Anyway I could see pictures of your setup? I am thinking this is the route I am going to do as well but would like to see it if possible. Visuals are my friend lolā¦ also is your machine a 30x30?
