Greetings, I would like to upgrade my OX Metal CNC Spindle From: Quiet Cut Spidle, 300W 12,000 RPM as stated the my build spec below: To: GMT Air Cooled CNC Spindle 1.5 kW 220 V 24000 RPM R / GMT Air Cooled CNC Spindle 1.5 kW 220 V 24000 RPM R | Air Cooled Spindles GMT Air Cooled CNC Spindle 0.8 kW 220V 24000 RPM R / GMT Air Cooled CNC Spindle 0.8 kW 220V 24000 RPM R | Air Cooled Spindles I wanted to Know if anybody has had experience with: 1.) going to these Spindles on an OX CNC build and 2.) dealing with the weight factor on their existing Z axis assembly. I would like to go from the 12,000 RPM to 24.000 RPM, which I gather is the upper safe limit based on other posts that I have read here, basically: 1.5kW - 24,000 RPM, 2.6kg / 5.7lbs is about as far as you may want to go for any build that uses V-Slot 20x60-80 mm with 1/4 thick aluminum Gantry ... With this in mind I am concerned with the weight factor THE UGRA CNC spindles appear to be pretty decent quality and a bit on the heavy side to address any weight issue associated with the Neama 23’s that I am using I am also thinking of adding a Gas Spring: McMaster-Carr / McMaster-Carr The gas spring does not restrict rapid Z movement…. it should help, I am thinking that the Z axis motor would have less load to lift as the compressed gas spring is offsetting the weight of the moving components and spindle, so the motor lifts much less weight on when beginning to lift the Z up. Comparatively Gas springs are better than extension springs for Z counterbalance, my preference is an air cylinder as it can be adjusted with a regulator and with some fiddling, your Z will be "neutral buoyancy". Meaning… I think.. not sure that that there is the same force required to raise the Z as lower it. I thought about this as I recall a car that I used to own had these Gas cylinders on them … So has anyone had any experience with: 1. Gas Assist installation on the Z Axis? I would like to see how it was installed 2. Installing a spindle with a weight factor of 7 -9 Lbs. on an OX CNC … any known issues? All input appreciated, Regards, Ed Zacly My Build Spec: OX Metal CNC V-Slot 20x60mm, 750mm / 29.5 in long (X axis) Gantry V-Slot 20x60mm, 285.75mm / 11.25 in long (Z axis) V-Slot 20x80mm,1500 mm / 59" Length(Y axis) Bed Spidle Quiet Cut Spidle, 300W PN: 30416-01 Operating Voltage:12- 48VDC S Speed: ~12,000 RPM @ 48VDC Collet: ER11 Spindle Runout: ~0.0006 Collet is an ER11-A Nema 23 Stepper Motors
You can resolve a lot of the Z-axis issues by simply using a milder lead on the screw. Drop back to a TR8*2. Not only does it give the stepper effectively 4 times the lifting strength it also gives you 4 times the vertical resolution. The only issue beyond that is the torsion it puts in the X-axis rail and the adverse effect it will have on cut quality. This can largely be resolved using a parallel rail.
Greetings Rick 2.0, Thank you for responding, Sorry, I should have included that detail in my Build Spec, this is what's installed on the Z Axis, purchased from Maker Parts for my OX Metal CNC 8mm Metric Acme Lead Screw 8mm Metric Acme Lead Screw •Tr8*8-2p (4 starts) •Lead Screw Diameter ∅ 8 (mm) •Pitch 2 (mm) •Lead 8 (mm) •Stainless Steel So basically since I already have Tr8*8-2p installed, I should be able to install either one of UGRA CNC spindles without issue? no gas cylinder assist required, which spindle would you go with? GMT Air Cooled CNC Spindle 1.5 kW 220 V 24000 RPM R / GMT Air Cooled CNC Spindle 1.5 kW 220 V 24000 RPM R | Air Cooled Spindles Weight: 4 kg (9 lbs) GMT Air Cooled CNC Spindle 0.8 kW 220V 24000 RPM R / GMT Air Cooled CNC Spindle 0.8 kW 220V 24000 RPM R | Air Cooled Spindles Weight: 3 kg (7 lbs) Thank you & Regards, Ed Zacly
No, I'm referring to a single start TR8*2. Each turn of the screw is 2mm not 8 as with a TR8*8. This offers several advantages. The two most useful points are noted above but the most important is that should a power failure occur, the weight of the spindle doesn't have near the leverage on the screw and the spindle can't come crashing down. Detent torque of the motor alone is sufficient to keep the motor weight from spinning the screw. But again as noted above the TR8*2 screw gives you (roughly) 4 times the lifting power with the screw and 4 times the vertical resolution on your milling.
Right...sorry, I should have picked up on that... I will replace the TR8*8 with the TR8*2 When I install the heavier spindle from UGRA CNC. Thank you for the input .. much appreciated... Regards, Ed Zacly
Rick, One final question... you have a technical acumen that I lack, for the sake of maximum benefit, for the Ox Metal CNC that I have, which spec (see below) would you suggest, I know the .8 KW / 1 HP would likely suffice for my current set up, but would the 1.5 be viable in your opinion? from everything that I have red in this forum 1.5 KW would be the max upper end for my set up... and I suspect that it would be underutilised... OX -Metal Gantry Assembly X-Axis V-Slot 20x60mm, 750mm / 29.5 in long (X axis) Gantry V-Slot 20x40mm, 750mm / 29.5 in long (X axis) Gantry Deluxe 2" Taller Gantry Plate Set for the OX CNC Regards, again ...Thank you Ed Zacly,
Sorry, not really in a position to say as I have no experience with either one. Hopefully someone will chime in who does.
Noted, Thank you just the same.. Sorry that information did not stay organized when I posted it - I meant for the comparison to present in two columns
Why do you want a large spindle? What are you cutting? Why is RPM your emphasis? That looks like a 1.5m x 1.5m build. You won't be able to really use what both spindle options offer. You'll be throwing around way more weight than you can handle. For reference, a palm router is usually going to be less than 3.5lbs. That's half the weight of the 800W spindle. Spindle weight isn't a z axis stepper motor issue. It's a complete X-Y-Z issue.
Hi Kevon, Thanks for responding, I appreciate the input... I am routing out wood signs, pine, cedar oak, Maple and machine grade MDF etc.. I am looking to get into the 20,000 RPM range to reduce machine time, I prefer spindles over a router for two reasons: My CNC router is in my basement shop which is in the house, so noise is a bit of the issue I also like to dial down or up on the rpms depending on conditions.. which I do from the GRBL panel The diameter on the .8 kw spindle is .65mm vs . my current spindle 52 mm, so it's within the physical constraints of the spindle mount if modified .. My X axis is double beam, as per the spec below, I agree that I wont be able to use the upper end of the spindles capacity / range but 70% at 20,000 RPM would be sufficient to reduce machine time, admittedly my range of experience is with the 300 watt spindle at 10,000 rpm so my frame of reference is limited, hence my posting, also I plan to convert the OX metal CNC to a laser set up and would move the .8KW spindle to the next heavier build, which I know I need to migrate to so this was an in-between approach... short term.. I was hoping to go to the 1.5 because the .8 KW will be under powered for the next build … Trying to find the happy medium... any suggestions on a spindle would be appreciated Gantry Assembly X-Axis V-Slot 20x60mm, 750mm / 29.5 in long (X axis) Gantry V-Slot 20x40mm, 750mm / 29.5 in long (X axis) Gantry Deluxe 2" Taller Gantry Plate Set for the OX CNC
Are you wanting to go watercooled or air cooled? Air would be a little simpler and can help clear material after being cut, but it does have disadvantages. You shouldn't run below a certain RPM (I've seen 9k minimum) as a result of the fan being mounted to the spindle shaft for cooling. It has the potential to blow dust around. The noise increase is irrelevant due to the fact that the act of cutting is far louder. Finding an air cooled 0.8kw spindle is a little difficult, but they are out there. https://www.amazon.com/0-8KW-Cooled-Spindle-Variable-Frequency/dp/B010S7BNQY
