Hello, I am in the process of designing a new CNC. I will be using this for wood, plastics and aluminum. I am hoping to build something that is strong/rigid, durable and accurate that I do not need to fuss with too much. I have built a 4'x4' torsion box bench for it. I am planning on building the unit slightly larger than 4'x4' so that I can cut something that is up to 4' long. I plan on attaching extensions on the sides of the bench to attach the CNC to. I would love to purchase a kit but there are no kits in the size and price range I am looking at that meet my criteria. Here are some pics of my design ideas. There are some areas I need some help with. My X-axis is a 4080 C-beam with a 4040 extrusion attached to the top. Most likely I will also add some type of plate on the back side to tie them together more and give it even more strength. I also am trying to design the gantry sides using extrusions as well. Currently I have two 2080 extrusions side by side (500mm long) with a 2040 (380mm long) in between. Then I added a 2080 (380mm long) on the outside to help lock them all together (I have not added the brackets yet). The 40x120mm long opening in the gantry sides is where the X-axis comes through. I have the X-axis come through 20mm so that I can lock it on both sides with L Brackets. I will also add brackets/plates on the top and the bottom as well. I am also planning to use HIWIN linear rails and blocks on all axis'. Currently I have the Y-axis linear rails mounted on top and bottom of the C-Beams. I feel that this is a more secure/strong design than putting the rails on the outside edge of the C-Beams. I think either way will be plenty strong but I like this design better. BUT I am having troubles finding a way to attach/space the nut block to the inside of the gantry sides and have it perfectly aligned with the lead screw. Based on this design I would need a spacer that is .5354" thick. I know this is not a big deal but I would really like be able to purchase most/all of my parts (off the shelf) and not have to have something custom made. Also I am having some trouble with finding a mounting plate for linear rails that are mounted in this way (top and bottom). I have seen plates out there for linear rails that are mounted on the outside of the C-Beams. Because of this I may consider changing my design in order to make it easier to build. My solution so far in my design is to use 1/4" aluminum angle (2"'x3") top and bottom. I can make this work but would love to find a solution that is made for this. If I went with this solution I will still need to figure out the best way to attach all the pieces to each other. This is as far as I have got so far. Before I wrap this up I wanted to mention another feature to this design that I like is that the Z-axis capacity is not limited by the Z-axis assembly (200-250mm). This design allows me to move the entire gantry up and down for times when I need that extra space. Most of the time I will have the gantry assembly down close to the workspace and where the Z-axis assembly is up high with just a couple/few inches of movement so that there is little leverage during operation. I know that it would be a chore to make these adjustments but I think I can come up with a way to make it easier. I have considered purchasing a plate set from [someone who shall not be mentioned on this forum] and then build my unit around those plates. BUT I don't feel that the X-axis would be as strong because it only uses the 1 C-Beam. Also I am then limited in gantry height, which is not deal breaker I guess. The plates are 10mm which is quite thick so I think they would be fairly strong/rigid. AND I don't have to try and figure out solutions for the things I do with my design so far. Ugh Does anyone have any thoughts or advice? Or maybe you have seen some solutions/parts out there that would be helpful? Thanks, Shawn
As an official Openbuilds re-seller hopefully these can be mentioned here, unlike some others I definitely won't name. Rat Rig KillerBee CNC - Full Steel Plate Set Alex.
Shawn, are you looking for a plate to replace the two 2"x3" aluminum angle? If so, I guess, going by your pictures, the plate has to be 6". Could this be a solution?
Thanks for the info. I will look into that to see how they are designed. The link did not show any pics or info on the product. I have seen the Rat Rig's before. I actually am looking at a plate set from Blue OX Solutions. I may end up going that route. Thanks for the link. Yeah if I go with this design then I will need to figure out a good solution for attaching the gantry sides to the blocks. I doubt I will be able to find something that is the perfect size without having it made. But I will look into this aluminum channel. Might be able to make this work with some shimming. Thanks for the info.
Blue Ox is potentially a good solution. If you have Fusion 360 there is a cad model of the Killerbee here; Fusion if you haven't got Fusion you can still view it. I assume you have looked through the Openbuilds parts to see if there is anything suitable? Alex.
I really like the KillerBee because they use steel plates but the link to the plate set you linked gives me no information about what comes in the set. Plus I cannot find that set listed in any of their categories. I have a hard time forking out $350 on a blank product page. I will contact them and try to get more info. Oh and thanks for the link to the Fusion file. I like to build all my projects in Fusion. I was disappointed that Blue OX does not have their plates available in a STEP file.
I used aluminum angles to attach mine. I used the hole pattern of a cbeam gantry plate. This plate is attached to the the upright extrusion. By doing it this way the spacer block I need for the nut block is a little over 12 mm. Lucky for me my 1/4" aluminum plate is just a little over 6 mm so I will need to just skim a bit off the top of one spacer plate.
Thanks for the info. I am still trying to figure out which way I want to go. Having trouble finding mounting plates for the HG series HIWIN linear guides. Thinking I may have to manually create the plates I need to get the machine built and then machine the parts after it is up and running.
I manually made all my plates with a drill press, chop saw, and table saw on my first build. I am currently upgrading that machine to be similar to the LEAD High Z but with linear rails. I have cut all the plates and started some assembly, but got side tracked by building a CNC lathe.
Dang It! Why did I have to check my post. Now I am rethinking some things after seeing your build. Ugh! I have a few questions for you. What size extrusions are you using for your XYZ axis'? Have you used it to cut aluminum? If so, how did it go? Any issues with flex or accuracy? Is that v-slot or t-slot? Is your angle steel or aluminum? What thickness? Thanks for the info!
I have not completed these modifications yet. It is basically a Lead 1510 with a high z modification using the c beams for all axis. The difference is I am using linear rails and I made custom plates for the router mount and plates to mount the two x axis beams to that will keep them secured parallel. My plan is rather than slide the z gantry c- beams up and down like the high z mod, my entire x axis will have two positions. One high up for doing thicker 3d relief carves out of wood and a lower position resting on stop blocks for a majority of the work I do like cutting plates from aluminum and other thinner materials. I cut aluminum now with my older design using just one 850 mm long doubled up 8020 v slot x axis and v wheels with no real issues. I figured having 2 cbeams like the high z mod should be more than adequate.
