King Pdm-30 Mill - Here We Go Again.

Next issue in the PDM-30 saga. I finally decided to use it the way it is and just face a piece of scrap mild steel. I haven't bothered to tram it yet, just want to see how it cuts with the existing vibration.
Now I discover there is 0.030" backlash in the spindle (z axis). Holy crap :eek: that's a lot!! The owners manual has no information about adjusting that. Is this normal for these round column mill drills. I've read a few threads about people creating / having a fix which involves keeping down or up feed pressure on the quill to resolve this but can't find any posts indicating what amount of backlash they started with. If it's normal then I will just have to develop a method to deal with it or implement one of the solutions others have created.
 
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HBilly1022 said:
Next issue in the PDM-30 saga. I finally decided to use it the way it is and just face a piece of scrap mild steel. I haven't bothered to tram it yet, just want to see how it cuts with the existing vibration.
Now I discover there is 0.030" backlash in the spindle (z axis). Holy crap :eek: that's a lot!! The owners manual has no information about adjusting that. Is this normal for these round column mill drills. I've read a few threads about people creating / having a fix which involves keeping down or up feed pressure on the quill to resolve this but can't find any posts indicating what amount of backlash they started with. If it's normal then I will just have to develop a method to deal with it or implement one of the solutions others have created.
Click to expand...
I find with my mill best to keep a little pressure on the quill lock handle as I feed with the fine adjust. Then fully lock when I set doc. I know I can get couple thousand flex (measured from spindle to table) in machine just from grabbing belt cover and push up or down. Still better in my mind than princess auto mini mill. Not sure what your instructions say on howto tram your mill. I think mine can only be trammed with shims under pillar mounted to base.
Jack

Sent from my SGH-I337M using Tapatalk
 
atlas ten said:
I find with my mill best to keep a little pressure on the quill lock handle as I feed with the fine adjust. Then fully lock when I set doc. I know I can get couple thousand flex (measured from spindle to table) in machine just from grabbing belt cover and push up or down. Still better in my mind than princess auto mini mill. Not sure what your instructions say on howto tram your mill. I think mine can only be trammed with shims under pillar mounted to base.
Jack

Sent from my SGH-I337M using Tapatalk
Click to expand...

Thanks, I'll give that a try. My instructions don't say anything about tramming but from what I've read about these round column mills, it is done by shimming the column base mounting bolts, as you noted. I just did a preliminary test with my DTI and it seems ok but I didn't have a long enough indicator arm to get readings very far from the spindle center. Since I don't plan on making anything requiring a high degree of precision I think that will be good enough for now. I took some indicator readings on the vise that came with the mill and it seems to be warped. I will probably try milling it to make it parallel to the table or maybe I'll make one. Buying one is an option too.
 
I just measured mine, .021" backlash on Z axis. In a previous post, I mentioned adding a DRO to the Z axis. IMHO, it is a requirement, not an option, if you want to have any idea of where the quill is. At least with the DRO, you will be able to see when it moves, and adjust accordingly.

Fortunately, an Igauge or digital caliper will work, and is not very expensive.

Another fix that is on my to do list is to add the gas spring that Rick Sparber describes in this link.

http://rick.sparber.org/ZABG.pdf
 
I don't think it has to be very far off center to take tram reading. I know mine is off. I can tell when i use fly cutter only 1 3/4". I'm thinking they sold you cheap vise possibly for drill press. I use clamp kit so far from kms. I want to get a vise and rotory table just not in the budget. Quickly adds up one tool to make another and another. I got ultimate v blocks from busy bee. But they are not made from same plans. I bought them several months apart and same day.
Jack

Sent from my SGH-I337M using Tapatalk
 
Ben Nevis said:
I just measured mine, .021" backlash on Z axis. In a previous post, I mentioned adding a DRO to the Z axis. IMHO, it is a requirement, not an option, if you want to have any idea of where the quill is. At least with the DRO, you will be able to see when it moves, and adjust accordingly.

Fortunately, an Igauge or digital caliper will work, and is not very expensive.

Another fix that is on my to do list is to add the gas spring that Rick Sparber describes in this link.

http://rick.sparber.org/ZABG.pdf
Click to expand...

After only using this mill a couple of times now I have to agree that some other means of reading the z axis is an absolute must. My drill press has a better system for reading the DOC and setting a stop. I'm really beginning to understand why this much more powerful mill was only $200 more than the smaller King model with nicer features but a very small motor. The trade offs are getting more obvious. Anyways, there are a lot of owners of the similar machines that seem to be quite happy, so I guess it can't be all that bad.

I just got back from the shop and finished my first real work on the mill. I used a 5/8" end mill and trued the el cheapo vise to the mill. The vise ways (if that is what they are called) are now parallel to the mill table and I squared up the fixed jaw at the same time. It went well. No chatter and no issues other than trying to set / read the z axis, noted above.

On another note I contacted the closest service center and explained the motor heating issue. I was told that's not normal. So I called the dealer that sold me the mill and asked him to see if he could get me a new motor, rather than me having to drive 3hrs to the service center, drop it off and drive back for 3hrs. Then have to do the same thing all over when the motor was repaired. He is going to see what he can do for me. I'm glad the dealer is helpful. Otherwise this could be a real PITA.
 
Update: Got a call from King Canada's head office today and I explained the situation. The guy I talked to said to send him the original tag from the motor and a brief written explanation of the issue and when he receives the tag he will ship me a new motor and drawbar. Things are looking up.:eagerness:

I've also been using the mill more and I'm starting to get used to the Z axis issue. The mill also seems to be very sturdy and working well. With the comfort of knowing the motor issue will be looked after I can now focus on learning how to use this new machine. I've already read a bunch of the Rick Sparber links and need to do a lot more reading.

In the meantime I'll start with some simple tasks and work my way into more involved projects once I get a better feel for milling. I think my first projects will be to make a carriage stop for the lathe and redo some of the parts I made for the lathe taper attachment. I'm not happy with the way some of the parts turned out and now that I have a mill, I should be able to produce much better and more accurate parts.
 
Ben Nevis said:
Here's a video on adding DROs to the mill.

Click to expand...

Ben, I watched that video and I really like that set up. I think I will do something similar. I already checked out some sources for the DRO and the best price I could find was pretty decent. Unfortunately they are currently out of stock. I guess I'll wait until they get another shipment in.
 
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