Researching the 4x4 machine and need a little information around the max Z axis travel. I need to cut the heel section of an acoustic guitar neck which is 3.75”. To do that, I’ll likely use a 1/2” diameter, 4” long, ball nose bit. I understand the gantry clearance to be 5.5”, which is good. What I don’t know is, with that long of a router bit, will I have enough clearance in Z axis travel for the bit to clear the top of the part.
Appreciate any feedback you can provide.
@tjpilson Welcome to the group, Tim.
According to the Altmill specs on the Sienci site, the max Z travel is 6.35". Others with Altmills will, no doubt, join this conversation, but I don’t see how you can run a 4" bit over a piece of material that is 3.75" on an AltMill. By my way of thinking, you would need a minimum of 4+3.75 = 7.75". That’s almost 1.5" more than the max Z travel.
That’s an interesting project Tim. As said above the clearance may not be possible with 4 inches of bit. But you may not need that long of a bit. Here is a video of one being carved straight up and one video of the heel being carved on its side. Its not an Altmill but you get the idea.
Not sure if this helps but it looks like a fun adventure.
The “carve up” example is exactly what I’m looking to do. That looks to be a 3”-4” bit from what I can tell. Based on the earlier comment, it sounds like that would need more travel than the AltMill is capable of.
I have considered the side cutting option but if I’m making the CNC investment (currently have a smaller machine), I’d like to upgrade to something capable of that.
Thanks for the info.
I thought I would try a set up for you. Here I put a 3.75 inch block on the frame below my spoilboard. I maxed out my spindle to its limit. Then I pushed the spindle a far up on the clamp that I felt was safe and strong. I then placed a dowel in the spindle and left 4” exposed. Here was the results:
Looks like it would work if you made a jig that attached to the frame instead of a spoilboard.
@tjpilson You could always lower your table in between two cross rails. That’s what I did in order to be able to surface the edge on 6" stock. It’s at the back, so the cutout doesn’t interfere with most of my projects
@Karver_One With that set up, with the dowel still reach the spoilboard at the bottom of the travel? If the AltMill specs are correct, it shouldn’t.
@gwilki I see what your saying, but I wonder if they were basing those numbers on a specific setup. Since I have seen some of the Sienci staff put their spindles very low on their videos. Of course they are being very safe because if I was cutting hard steel I would like my spindle to be a little lower so as to have spindle clamp give more “bite” to the spindle. Or possibly they were basing their numbers on a Makita router setup. But I must admit I found that it does actually reach the distances Tim was looking for and funny enough….with room to spare. Wild, I learn something new about this machine everyday =)
@Karver_One That’s odd, because where the spindle is in the clamp has no bearing at all on the amount of Z travel available. If Z will travel, say 6", it will travel 6" with the spindle low in the clamp, high in the clamp, or not on the machine at all.
Anyway, as long as @tjpilson can do what he wants, it doesn’t matter. It would seem that the Sienci documentation should be amended to reflect the actual amount of Z travel though.
Really appreciate you going through the effort to test/demonstrate on your system. Extremely helpful!
