I heard the same thing regarding noise level. It made me think twice about changing out the gear box gears to metal ones. But I figured what the hell, my hearing is already shot from years of shooting and driving blown alcohol dragsters, back before we knew any better.
I know what you mean about the 4" grinder, that thing is obnoxiously loud even with my somewhat impaired hearing. lol
I have the LMS belt drive. I don't remember what the gears sounded like, but I don't remember any particular change in noise level. It sounds like a jet engine preparing for take-off.
Most of the noise comes from the motor, best as I can tell. I've had the spindle apart; it's just a shaft in two ball bearings, I can't see where there'd be anything there to make much noise.
Mill was delivered on wednesday. I immediately tore it down to go through it and add upgrades. Good thing too. Of the 4 bolts that hold the motor to the mounting plate, two had all ready fallen out and the other two were about to.
Originally Posted by TRX
As soon as I started disassembly I discovered that the motor was loose, when I separated the motor from the plate, two screws fell out into my lap. If not for the fact that they are held captive by the mounting plate, the screws would have been gone completely. I also found several other screws that were loose. Pretty clean inside though compared to some reports I've seen, no swarf to speak of.
Today I am changing out the gears in the gearbox for the metal ones, adding the air spring and the column support. I also have received the DROs for all 3 axis, they will go on next.
Keep an eye on your mounting screws for the DRO's. Mine loosened up over time.
Had used lock washers when I installed the DRO's, but they still loosened up. Used a dab of blue Loctite to hold them in place.
7.62x39 what method are you going with for the column support? Did you have to machine supports/mounting brackets to attach the DRO's?
For me, it will become a chicken or egg issue if I need to make mounting brackets. Got my machine on Wednesday also. Trying to decide if I want to mount it to a 4 drawer rolling tool cabinet or a fixed bench.
I got the column support pieces made.
Now it's time to build a mill. I've received AK kits that were closer to being a rifle than this is to being a mill. LOL And this is after I got the gear box all reassembled.
The biggest knock on these mills is the inability to achieve and maintain a perfect Z axis alignment. The main reason is because of the tilt "feature". In order to be able to tilt the column, the column is secured by just one big nut. This is the weak point. I see no reason for a tilting head/column so I eliminated it.
With this set up I can tweak the column in all four directions and lock it up rock solid. The L brackets on the sides allow me to adjust left to right and the clamping fixture at the base allows me to adjust front to back.
The larger bolts in the middle of the bar just pass right through it. The plate itself is tapped to 7/16-20, tightening of the bolts applies pressure to the base tilting the column forward. The two outer bolts thread into the base, tightening these, moves the column rearward.
Now I can tram it perfectly and lock it up solid.
Next up is installing DROs on all 3 axis.
I got it finished up over the weekend.
I was able to make all the brackets required by reshaping the universal brackets that came with the DROs
All that's left to do is to make a mount for the display units.
Pics of X & Y axis DROs
Pic of he Z mount and an 80% blank ready to go.