Precision Matthews PM-728V-T Mill

[EdK]

Got a start on reassembling the mill. The column bolts to the base from the bottom so if it's out of tram there's no access to the bolts unless you built a stand to accommodate access to them. I almost forgot about the shims, good thing my brother remembered otherwise I'd be tearing it apart again.  

I'll get the saddle on this evening and then we'll put the table on in the morning followed by the head in the afternoon. Getting anxious to make some chips.

Ed

   

[EdK]

Now it's starting to look like a mill. Just have to install the one-shot oil system and go over the mill to make sure everything is as it should be then I can make some chips.
First project will be a work stop for the vise.

Ed

   

[Highpower]

Looking good Ed.

[EdK]

Head is trammed to within .001", vise to .0005". No time today to make chips so tomorrow will be its maiden voyage.  

Ed

   

[EdK]

Yikes! That's one dirty mill.  
Decided to make Tom's stack blocks first. Then I'll make the vise work stop for the mill.

So far I'm pleased with the PM728. It's a much better mill than the PM25. There's one mod I want to make to it to make it even better. I'll document that when I start the project.

Ed

   

[EdK]

Having used the mill for a while now, the motor is definitely under powered. It's curious that PM's cheaper made in China mill has a 2HP DC motor but the PM-728 only has a 1HP DC motor.  

I'm not the only one complaining about the wimpy motor. One guy replaced his with a servo motor, not for CNC purposes but just for the increase in power especially at lower RPMs.

There were a few things that I had to fix in order to get it to run smooth and now, other than the wimpy motor, it's running pretty smooth.

One other thing that I don't like about it is the X and Y handles. They have a revolving handle that's nice and smooth but the revolving handle is so heavy that it causes the whole handle assembly to move when it's at certain angles. I think I'll try to add some weights 180 degrees from the revolving handle to balance the handle assembly so it doesn't do that.  

Ed

[Highpower]

(09-09-2022, 07:41 PM)EdK Wrote: I think I'll try to add some weights 180 degrees from the revolving handle to balance the handle assembly so it doesn't do that.  

Ed

Or remove some material from the back side of the wheel on the handle side...

[EdK]

(09-10-2022, 09:30 AM)Highpower Wrote:

(09-09-2022, 07:41 PM)EdK Wrote: I think I'll try to add some weights 180 degrees from the revolving handle to balance the handle assembly so it doesn't do that.  

Ed

Or remove some material from the back side of the wheel on the handle side...
...

Unfortunately it's not solid, it's hollow on the back side. It has hollow slots on the back side of the rim so I can cut some metal and glue it inside the slots.

Ed

[Highpower]

(09-10-2022, 11:37 AM)EdK Wrote: Unfortunately it's not solid, it's hollow on the back side. It has hollow slots on the back side of the rim so I can cut some metal and glue it inside the slots.

Ed

Oh for Pete's sake! No wonder the weight of the handle is dragging it around.  
Got a spare 12ga. bird-shot shell handy?  
Take the handle off and weigh it. Open up the shell and weigh out the same amount of lead shot. Dump it in the slots and cover with hot glue or epoxy. Bob's your uncle. That is how I adjusted the balance point on my competition rifles. Lead shot inside the butt stocks. Works a treat.

[EdK]

(09-10-2022, 12:42 PM)Highpower Wrote: Oh for Pete's sake! No wonder the weight of the handle is dragging it around.  
Got a spare 12ga. bird-shot shell handy?  
Take the handle off and weigh it. Open up the shell and weigh out the same amount of lead shot. Dump it in the slots and cover with hot glue or epoxy. Bob's your uncle. That is how I adjusted the balance point on my competition rifles. Lead shot inside the butt stocks. Works a treat.

Good idea! Although I don't have any shells. Searching for lead shot it looks like it'll be a lot cheaper to buy a box of shells and gut them than to buy a bag of lead shot.  

Ed