Any idea how we can improve the weakness in how the spindle and z-slider is mounted? I don’t see the point of a stiffy if the weakest point comes way before it.
2 Likes
I agree ! The mechanical link between the spindle and the Z-slider is kinda weak compared to the rest of the machine:/
Something definitely needs to be done about it. All the engineering that went into designing this CNC is such a waste if this is not addressed.
I built my own z out of 19mm. New rails and ball screw. 350mm travel. Attaches with the stock m5 bolts and also attached to the top stiffy rail. $250 in parts.
I still have full range of motion on x.
I cut the aluminium using a small stock z and 2.2 kw spindle.
2 Likes
+1 here on that! I’m pretty happy with my machine so far but will admit that the whole Z assembly is disappointing. With all the beef the rest of this machine has, and the Z slider is held on by four puny little m5 screws! Furthermore there is no mass left in the block in the event you might need to do a thread repair. The stiffy is not adding as much rigidity as it could. And the mount ring for the spindle is hilariously inadequate. I realize the intention is usually for a trim router, but the 80mm version should be much more substantial.
I’m in the process of building a MUCH beefier 1 pc block that will fully incorporate the stiffy, have more clearance, better connection for the Z slider, easier access for maintenance and cleaning, as well as having a lot more mass to bolt on accessories (hose boom, lights, etc). I’ll be happy to share when it’s done.
And lastly I must say, in order to get my machine to flex as much as the guy in the video, I have to use a lot more force than the machine would be subject to while cutting. Could rigidity be better on the 1F? Sure it could, but any real deficiencies can be overcome with just better tooling and smarter toolpaths.
2 Likes
Have you actually tested for deflection forces and break points? I feel like looks may be deceiving and sure it may not look over built but for how the forces are exerted on it is it good enough? The stuffy would still stop twist or racking either way. Are we making an issue that isn’t real or is there truly data to show the problem
3 Likes
I agree. I did such testing before and after adding the X50 3rd rail, and again after I built my own Z axis assembly - similar to that described by Ryan B. above.
I would have to search the forum to find it but there were incremental differences with each successive modification - tens to hundreds of micron differences however.
I think like all machines, we as owners/users need to over time and machining hours understand the limitations of these hobby level CNC routers. Then we can choose appropriate and effective machining parameters to match our machine’s level of rigidity.
It reminds me of experienced manual lathe and CNC operators using sturdy old machines with a lot of backlash. They still make exceptional parts, but using years of experience learning how to compensate for the backlash.
5 Likes
After adding the stiffy to my X50 I made a piece of aluminum that mounts behind the stepper and ties it into the stiffy rail. I never bothered to check how much deflection there was after adding it but I do know that the amount of chattering did drop when pushing bits hard. That being said I have my 1F on 2 1/2" aluminum blocks (under the 4 feet) and have the slider mounted as high as it can go to maximize the Z axis travel. If you want I can take a picture of it.
2 Likes
Yes, Please do. I would like to see how you did it.
1 Like
Personally, I would pay for a beefier option that prevents this deflection. My worry is that Onefinity is too busy processing orders and no longer has time for improvements.
Worry free, @deafgoose.
Onefinity never sleeps, and never stops innovating.
7 Likes
Did you see any noticeable improvements in your cuts?
1 Like
Would love to see what you put together - can you share pictures and or plans?
This design uses hgh15 and a 1610 ball screw. It allows full x travel.
Running the small stepper until the new one arrives
3 Likes
man that looks beefy. are yu selling or do you have plans for sale?
That was v1, v2 has the top plate on the stiffy connected to the back of the z plate, added elite sensors, other holes for stuff.
I like to cut aluminium; this has made a noticeable improvement. A wider z plate and hgh20 would have a better aluminium finish, but lose X travel
I would like to put some more hours on it before made it available.
I used hiwin hgh15 x 350mm & 1610 ball screw
2 Likes
I basically installed it at the same time I installed the stiffy. I did see an improvement but I can’t say how much was the stiffy and how much was the bracket. If I’m using a sharp 1/2" flat endmill I really have to push the DoC and speed now to get any sort of chattering. Even then it’s only when cutting end grain. If your handy and don’t mind drilling and tapping holes it really wasn’t hard to make. Anything that helps make it stiffer can’t hurt.