Not sure about Delrin for this.
+1 
IMO direct drive is the only way to go when thereâs an investment like this.
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Can the rail plate be >1/4"? That seems to be a weak point with others.
I agree that direct drive is a better choice even at the cost of having to move center weight towards the router a bit. On top of that I donât believe flexible coupling belongs on CNC and rigid type should be used.
And I also believe people should be cautious with the travel distance they wish for, half of the reasons mentioned here call for raising entire X axis or even Y plates like many have done to gain clearance. You have to remember reach is also limited by size of spindle and necessity to grip to X gantry and Inventables while nice and solid takes lot of space on the spindle/router.
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Hi, Iâm new here, I will buy a used X-Carve from a buddy but it need a more rigid z axis.
I can be interested if you can use linear bearings like this one: http://www.ebay.com/itm/Z-AXIS-5-034-travel-ANTI-WEAR-NUT-slider-linear-actuator-X-CARVE-CNC-router-plasma-/152497735200?
Hope you can ship to Canada because the one in link canât:(
On the friction/wear element, Delrin is regularly used as the material for the blow-back bolts in paintball markers.
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You have mentioned a longer Z Axis in other threads, like 5.11" or 5.45" with your gantry lift plates in placeâŚ
where did you get this Zaxis? or did you make it?
I just did some testing with more aggressive aluminum cuts. Previously with the wheeled z-axis I found that the sweet spot was about 1 square mm (1mm depth x 1mm width of cut) before the machine would start to chatter. I use Fusion 360 for CAD / CAM so I would typically avoid slotting and plunging by using adaptive clearing and pre-drilling for bored holes. I just cut an aluminum part manually and was able to do 6.35mm deep (full thickness of the stock) by 2mm width of cut. This was with a fairly beat up HSS end mill. I did tried to do some very aggressive slotting tests (8mm deep by 4mm wide) but the spindle overcame the torque of the X-axis stepper and pulled it aside. I am running a 269 oz. in. NEMA 23 stepper on my X, and using a TB5650 driver board with linuxCNC for reference.
I think based on these results the 1/2" rods should be fine for stiffness, as well as the 1/4" thick backing plates for the brackets. I will design the âextended versionâ around probably 5/16 or 3/8 plate for a little more stiffness.
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I want this so bad! haha
I would be interested in a 7" version
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I am planning to make an extended version. It will take more testing on my part since I will have to make a custom acme screw for it, so it will probably come a little after the base version and/or have a slightly longer lead time to produce.
For those who want a longer version, I am curious if 6.6" (12" rod length) would suffice? The linear rods are available in increments of 2" so the next step up would be 8.6" (14" rod length) or custom cutting the rod though I am not too keen on the latter since they are hardened steel. The standard version (10" rod length) will have a little over 4.6" of travel.
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I would be happy with that. Actually⌠I would be very happy with that if the price were right.
Itâs not really a matter of whether Delrin has high wear resistance (it does) itâs more a matter of which grade of Delrin is used. They make gears out of Delrin, and use it on conveyor belts. One reason it lasts longer is because of its high heat resistance.
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I like IGUS stuff and have used it in robotics applications. Great for harsh dirty abusive applications. Cheap over seas linear ball bearing do not last in 3d printers. The stresses in routers are higher. Pay now or replace many times latter. Good bearing are expensive. Good rods are expensive. That said there are some high quality Chinese stuff. Itâs just that you never know what your getting.
Their full technical library can be found here;
Right now the approach I am taking is to make my own bearings on a lathe from Delrin stock. I got some Igus-style bearings (not sure if it was Igus but it had the same color) from McMaster and the ID was oversized far too much (0.3 mm). I may try ordering from an alternate source in case it wasnât actually Igus and/or they sent me 13mm instead of 1/2". Making them myself should be fairly quick and cheap though. I am testing with DuPont Delrin (homopolymer) brand stock â I may try the Teflon-embedded stuff but itâs a lot more expensive. I think since we arenât using this for a high-speed application (< 50mm/s on the Z axis typically?) wear resistance is probably the critical factor.
I did try Teflon (PTFE) but I think itâs too soft.
Oilite bronze is another option but Iâm not sure if thereâs a compelling reason to use it instead of Delrin.
Keep in mind these are simple sleeve bearings â proper linear bearings would be ideal but they come at a cost. Itâs the same reason X-Carve isnât built with ballscrews and linear slide assemblies from the factory. A set of âgoodâ linear bearings could easily exceed $100.
Sorry to jump off topic slightly, but what spindle and mount are you using here? Do I see a spacer on the spindle as well? I am totally for this z-axis upgrade as well⌠The 611 will be short lived.
It is an 800w water cooled spindle, came as a kit along with a 1.5kw 220v VFD.
Yes, Teflon is softer than Delrin. Making them yourself should save you money
I was also thinking about picking one of these up. How long have you had yours? Do you recommend it?
I got the spindle kit about a little over a year ago. Iâve been very satisfied with the spindle and VFD. I am running my machine on a LinuxCNC box and I have it set up with RS245 control of the VFD so it automatically changes speed to match the G code. It is a water cooled unit and for cooling I am using a PC 120mm radiator / fan. Even a quiet low-speed fan is adequate to keep it cool, no need for big noisy fans or double / triple wide radiators. Itâs a lot quieter than the DeWalt router and has a much wider range of speeds (down to just a few hundred RPM while still getting enough torque to cut softer materials)
Another big advantage is that it uses standard ER11 collets and collet nuts which are cheap and easy to find (Amazon etc.) I find myself using a lot of 6mm shank HSS bits as well as 4mm carbide and various black oxide stub-length twist drills for doing work on aluminum.
I wanted to provide an update since I havenât posted news on this project in a while. I am getting very close to the point where I will be able to start producing and selling these â hopefully within the next 2 weeks or so 
A few key points:
- Main item will be the âstandardâ kit with 4.6" of travel. This will utilize the acme screw, nut, and Z motor mount / drive components from the base X-Carve machine
- âExtendedâ kit with same features except 2" longer travel will be offered on a limited basis. This will include a new custom-made acme screw to accommodate the extended travel distance.
Two additional developments:
- Anti-backlash delrin acme nut. Can be used with standard v-wheel axis or slide axis. I have designed this but I need to make and test some units.
- Direct-drive motor mount. Will utilize thrust and radial bearings to unload stress from the motorâs shaft and bearings. I need to work on this â I donât have the bearings yet
As far as selling etc. goes my plan is to use Fulfillment by Amazon which will allow for Amazon Prime fast shipping etc.
The feedback Iâd be interested in:
Any thoughts on using Amazon? Other sales channels?
Would the users who wanted the âextendedâ version mind using the belt drive until I am able to finish developing the direct-drive assembly? Like most of the parts Iâm developing, the direct drive would be a drop-in replacement and could even be used with the v-wheel axis.
Any feedback is appreciated!
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