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+--- Thread: Setting Up My PM935 Mill (/thread-2981.html)
RE: Setting Up My PM935 Mill - Mayhem - 01-23-2016
I would remove the screw as a last resort Ed. If your mill is constructed like mine, which I am sure it will be, the bearing is going to want to come out with the screw. If there is a bearing retainer in place, you may be able to carefully tap the elevation screw out. Each blow of the hammer is going to move the inner race down, whilst keeping the outer race stationary. Thus, the force is going to be placed on the balls. If the actual bearing comes out, it can be a pain in the arse to put it back in.
As I was replacing the bearings, I wasn't really worried by hammering on the screw (copper hammer) to drive it out. Additionally, there was no option for me to protect the bearing whilst doing this, as the diameter of the screw is larger than that of the inner race. You should always apply the force to the bearing face when installing/removing (if you are going to reuse them), as this prevents damage to the bearing.
When fitting a new bearing I had to make up a tool to install it into the knee by driving it only on the face of the outer race. Here is the tool - put together out of scrap I had on hand. It doesn't need to be pretty, only functional and with some luck, will never have to be used again!
[attachment=12627][attachment=12628]
You are working with new bearings, which is why I suggested tipping the knee so that you could lay it down on its back. I'm pretty sure I used a couple of pallets, so that I could lower the knee down and have the bottom sit on the edge, with enough height in the pallets to ensure that the bottom of the screw was above the ground. I then stood behind the pallets, facing the engine hoist and pulled the engine hoist towards me. Doing this allowed the knee to pivot on the bottom-rear edge and I could then bring it to rest on its rear face. Unfortunately, I don't have any pics of the process I have just outlined but it is quite easy if you think ahead, plan carefully and take your time.
When you come to reinstall the knee to the mill, I would screw the nut back on first (I'd unbolt the pedestal and leave the nut attached). The reason that I say this is because the damage that was done to the nut on my mill was most likely due to someone lifting the knee to high and then trying too lower it again.
RE: Setting Up My PM935 Mill - EdK - 01-23-2016
I'll have to read your post a few times before it sinks in but now you've got me paranoid.
Ed
RE: Setting Up My PM935 Mill - Mayhem - 01-24-2016
Sorry Ed - which part isn't clear? I don't mean to make you paranoid but I'd hate to see you damage the knee elevation screw bearing. If need be I can try and draw a picture.
RE: Setting Up My PM935 Mill - EdK - 01-24-2016
(01-24-2016, 09:10 AM)Mayhem Wrote: Sorry Ed - which part isn't clear? I don't mean to make you paranoid but I'd hate to see you damage the knee elevation screw bearing. If need be I can try and draw a picture.
No worries Darren. It's me, not you. After rereading your post with a clearer mind, it all makes sense now so I've decided not to remove the lead screw.
Thanks for the post.
Ed
RE: Setting Up My PM935 Mill - EdK - 01-24-2016
Got the knee safely tucked away on its sled.
I came in from the garage for some lunch and had a message from Arvid volunteering to come and help me with the knee. He's probably a little over an hour away from me so a huge thanks for the offer Arvid.
Ed
[attachment=12629] [attachment=12630]
RE: Setting Up My PM935 Mill - Mayhem - 01-24-2016
Well done Ed, you have saved yourself a lot of unnecessary work and your bearings will love you for it.
Its nice to see that Arvid came to help. I would have offered but I'm a little further away
RE: Setting Up My PM935 Mill - EdK - 01-24-2016
(01-24-2016, 05:24 PM)Mayhem Wrote: ...
Its nice to see that Arvid came to help. I would have offered but I'm a little further away
Arvid didn't come. I missed his call and didn't listen to it until after I had the knee on the sled. The fact that he offered to come and help is greatly appreciated.
Ed
RE: Setting Up My PM935 Mill - PixMan - 01-24-2016
Great offer from Arvid even if you weren't able to connect!
I see progress, and a new milling machine running in your shop soon. Keep at it, best of luck. I appreciate that you are doing it the safest way possible rather than the fastest or cheapest.
RE: Setting Up My PM935 Mill - EdK - 01-29-2016
The platform is ready except for the legs. I need to go get some more lumber for those. Hopefully I'll start the process of getting the pieces down into the basement tomorrow afternoon.
Ed
[attachment=12633]
RE: Setting Up My PM935 Mill - Highpower - 01-29-2016
So.... what's the tolerance on that platform Ed? +/- .005"
Ho-Lee!