Harbor Freight Mini Mill Motor Swap

[CNC_noob]

Well, I’m new to this forum and to machining, so please try to be understanding when I ask stupid questions... here’s the first one. I just bought an HF mini mill (model 44991) and just happen to have a Shop Fox mortising machine that I no loner use/need. It has a 3/4 hp, 8 amp, 3450 rpm motor that I’d like to put on the mini mill. Whattaya think? Am I crazy, or can this work?

Hey there. I am sure you’ve already finished you modification if you decided to do this, but absolutely you can upgrade the motor. I have changed the drive system twice on my HF mill because the original motor failed and I was dissatisfied with the gear driven transmission. Here are the iterations: replacement motor, replacement motor with belt drive, and upgraded replacement motor with V belt drive pulleys and idler.

 

[CNC_noob]

Hey there. I am sure you’ve already finished you modification if you decided to do this, but absolutely you can upgrade the motor. I have changed the drive system twice on my HF mill because the original motor failed and I was dissatisfied with the gear driven transmission. Here are the iterations: replacement motor, replacement motor with belt drive, and upgraded replacement motor with V belt drive pulleys and idler.

So I took all the gears out and fabricated a new drawbar that directly connected to the pulley. This is a direct drive on the belt system to the draw bar. Works great and cuts at a better feed rate and i can take a bigger bite with good results. I have a varistor for speed control and have ordered a 3 tiered pulley for the motor for gearing ratios (slower speeds).

i definitely recommend the v belt system over the smaller belt as I was out driving the small belt with the small motor where with the V belt i am able to run at full speed without issue. Make sure if you upgrade to secure the mill to your work surface and to use recommend feeds and speeds for the material you are cutting. I moved the power supply and controls external for the bigger motor and have added a tachometer to the old electronics area for monitoring rpm. I will upload pics later.
I am working on building my own metal lathe now, and I am going to build a 40 x 60 inch 3 axis CNC table soon as well (parts ordered). I will post a thread on this conversion and also on the other two later as well.
By the way..., I am no expert and a total noob to CNC, but I love to tinker on these things and building and modding my own stuff is a lot of fun.