Optimum MH 50V mods and accessories

[Unlogic]

I replaced the Noctua fans with Panasonic ASFP80391 fans that have 50% more airflow. I can now do continual milling for several hours without the spindle servo going above 40°C and without the casting of the head going over 45°C.



The machine is now in a state where it works great and I can make parts all day.



However the spindle is a limiting factor. It goes out of balance which causes vibrations if I go above 3000 rpm. Given that this machine was originally designed with a max rpm of about 3200 that's probably to be expected.

The way forward here is probably to buy a completely new spindle (without a quill) designed for higher rpm's. There seems to be a lot of BT30 spindles available online. However spindles for the larger BT40 taper which this machine uses seems a bit harder to find. I've sent out a few inquiries for pricing to see if I can buy a spindle from a known brand for a decent price.

 

[Unlogic]

I'm getting a bit braver with rigid tapping now and doing the threads to full depth.

I can see on the spindle load meter in Probe Basic (the LinuxCNC GUI I'm using) how much tougher the higher grade 7075/7050 aluminium alloys are to tap compared to the more common 6061/6082 alloys.

Tapping fine thread M10 (1.25 mm pitch) in 70XX series aluminum is probably close to the limit of what my 2kw Delta B3 servo is capable of in direct drive with a 1:1 pulley ratio according to the spindle load meter.

I think thread milling is gonna be the way to go for larger threads unless I upgrade to a beefier spindle servo.

 

[Unlogic]

I had planned to mill an aluminum purge block today but when I turned on the mill and pulled on the handle of the lubrication pump I was greeted by a cracking sound. A few seconds later parts came flying out of the bottom of the pump followed shortly thereafter by all the oil in the reservoir leaking out...



Upon closer inspection I found that the cast Chinesium part holding the handle had snapped allowing the internal plunger to shoot out along with the rest of the internals.



These pumps cost next to nothing new on Amazon/eBay however I needed to do some milling this weekend so a quicker fix was needed.

I designed this replacement in Fusion based on some stock I had laying around in order to reduce the time it would take to mill given that I would be unable to properly lubricate the mill during the operation. To shorten the milling time I didn't use any finishing passes, just milled everything to final size as fast as I could which can be seen on the finish.








All assembled with a temporary pin for the handle.




The part that broke had probably been flexing for quite some time because the pump has never operated as smoothly as it does now.

 

[Unlogic]

I attached a camera to the mill yesterday and made this little video clip.

I'm gonna weld some exhaust tubing with v-band flanges so I needed a way to cool them down while and align everything.