I was trying to cut out a shape in 0.85 inch deep wood but the cutter finishes the job about 0.1 inches short. In other words, the cut is not deep enough. In the toolpath window I set the lower end to be “bottom of stock”. I wondered if I had inserted the end mill too far into the chuck. Is there a correct way to insert a tool? How much of the shank should be inserted, or is it just a trial and error process?
I ran an “Initialise the machine” process without any stock loaded and tried to locate the z axis on the top of the spoilboard, but it ended up about 0.1 inch short of the spoilboard top.
Are you able to jog down so it touches the surface?
Did you measure your stock thickness accurately?
Is the tool secured so that it won’t push in?
Is the machine deflecting anywhere? Power up, jog to the center of each axis and load a probing pin and grab the tip of it and try to shift — does anything move?
Post the file and photos of the cut part (ideally still clamped in place w/ the machine at the origin or a specified offset), the overall machine, and upload the file?
The ‘most’ correct answer would be as long as the collet. You can cheat a little if you need some extra length, but I would not go much shorter than the length of the slots in the collet. You can go further in, but don’t bottom the tool out in the top of the spindle collet pocket. Push it in until it stops & pull it back out a smidge before tightening.
If you need to go 0.85 deep & the collet is 1" long, you want at least a 1.9" tool
If the collet nut is rubbing on the top of the stock, you definitely need a longer tool.
If the tool is long enough, but stopping before it gets to the spoilboard you may need to lower the spindle in the spindle mount.
In order of questions:
Don’t know. Can’t access machine until tomorrow.
Can jog but tool ends up short.
Yes
Tool properly secured.
No deflection. Don’t know what probing pin is, but everything tight about machine movements.
Not sure I know how to post files. Machine is Shapeoko 3.
Most of the C3D cutters have a maximum cutting depth. If you exceed that depth you start rubbing on the top of your design with the side of the bit. Additionally the bit can only stick out so far because every bit you put in the collet should be inserted at least to the top of the collet. With the bit inserted to the top of the collet you get the best grip on your bit. So overall length of the bit and the cutting depth is important to consider for deep cuts. An .85" depth of cut would require a longer overall length. The issues you can run into with longer bits is run out. As mentioned before the bit must be inserted at least to the top of the collet but the bit can be inserted farther but never all the way until the bit cannot be inserted further. The reason is when the collet nut is tightened the bit and collet are pushed up the inclined plane inside the router shaft. If the bit cannot be moved up it could be loose in the collet causing the bit to come loose and the top of the router shaft could be rough and induce router bit run out.
Here are a few specs for common C3D router bits.
#102 1/8" upcut has a maximum cutting depth of .5" #102E 1/8" maximum cutting depth of .5" #201 1/4" upcut has a maximum cutting depth of .75" #205E 1/4" has maximum cutting depth of 1.0" #251 1/4" down cut has a maximum cutting depth of .75" #122 1/32" .0625" maximum cutting depth #112 1/16" .25" maximum cutting depth.
So the only bit above that is capable of cutting .85" is the #205E. There are other manufacturers that make longer cutting depth bits. Cadance Manufacturing makes a 1/4" bit that can cut up to 2". There are others but the longer the bit the more the runout is exaggerated. When using long bits start up the router with the bit properly mounted and look and listen. If the router is making excessive noise or you see the bit vibrating excessively stop the router and remount the bit and repeat until the sound and vibration is normal.
Hello again…after a bit of an absence I am still trying to understand why my 1/8 inch end mill bit will not reach the top surface of my spoil board. I noticed on the Carbide cutter that there is a silver spindle which projects about 3 cm from near the base of the cutting assembly. There is a hole in this spindle through which I believe the z axis worm drive should pass, but on our cutter, the bottom of the worm drive ends up just short of the hole in this projecting spindle, in other words, just above it. Is this correct? Do you think the machine has been set up incorrectly. If I were to summon my DIY skills, I might be able to lower the z axis worm drive but I am not sure if this is “do-able” or even advisable.
The lead screw, or ball screw should be supported at the bottom end. Although, technically it should still work if it’s not. The axis is positioned by the linear bearings, the ball screw just drives the motion. Can you snap a picture of what you’re talking about?
The Z axis, as well as the X & Y, have physical limits. If the Z axis is all the way down & the tool will not touch the table, then the spindle/router needs to be moved down, or the tool needs to be extended a bit more. Ideally the tool should be inserted at least the depth of the collet. You can get away with pulling it out a little bit, but too much and it won’t spin true and you’ll get terrible cuts or break the tool. If the spindle/router is as low as it will go, then your only option left is to raise the table. Use a secondary spoilboard to get the extra height you need.
I’ve had another look at the router and noticed that its barrel was held in place by a substantial clamp adjusted by a couple of Allen bolts. I loosened these two bolts which were keeping the router in place by a pinching force / action. I’m not sure that I’m making myself clearly understandable here, but in short, as soon as the second bolt was loosened the router slid down inside the holder about two cm which was more than enough to get it closer to the spoilboard. I retightened everything and now my Z axis is fully adjustable right down to the top of the spoilboard.
On the matter of the worm drive (is this what you refer to as the lead screw?), I hope to enclose a photograph which shows the gap in question in my original query. This may be a fault in the set-up of the router, but better minds than mine will tell me if this is the case or not, and whether it can be rectified.
My preference for adjusting the height/position of the spindle is to insert the smallest tool I plan to use and then to lower the Z-axis as low as it will go, then adust the vertical position until the tool can cut as deeply as needed.
The height of a router is preference of the user. Most people tend to have it as far down as possible.
The picture of your Z-Plus with the stud with a hole is normal. The lead screw never goes into that hole and that is a stop of the Z-Plus. So the lead screw never actually goes into that hole in the stud. Looking at you would think that the lead screw would but it never goes in the hole.
The Z-Plus that screw is called a lead screw. On the HDZ it is called a ball screw. I think the technical definition is about their geometry. The actual shape of each. I found this on a google search.
Ball screws excel in applications where efficiency, precision and high-speed, smooth motion are preferred. Lead screws can be a suitable solution for simple applications where smooth or quiet motion is of more value than rigidity, precision, accuracy, and speed.
