Hi all,
Looking for opinions on how much I should try to fix on my new to me 1989 4020. I have the machine sheet metal off, and mostly apart, so it is a good time to go through everything and get it up to par. I would not be afraid to go at the ways with a grinder, as others have done, to make this machine more accurate, but don't have the tools or experience at the moment. A turcite job would be relatively easy at this point and within the "fixin budget" I have so I think I will probably do that at the least.
I'm not really sure how much I should invest into this old machine, or how fast I would "outgrow" it. My business is mainly engineering but I do love making things and try to keep that at least 25% of my business, I have a small shop with a couple other small cncs and prototyping tools. I have current projects that could absolutely benefit from having a 5 axis table, so I think that may be one motivator to get another machine in the shop in the future.
The current condition of X and Y:
-the number on the table in the last photo were from indicating it prior to leveling, I saw about .001 improvement on both sides of table once level.
Looking for opinions on how much I should try to fix on my new to me 1989 4020. I have the machine sheet metal off, and mostly apart, so it is a good time to go through everything and get it up to par. I would not be afraid to go at the ways with a grinder, as others have done, to make this machine more accurate, but don't have the tools or experience at the moment. A turcite job would be relatively easy at this point and within the "fixin budget" I have so I think I will probably do that at the least.
I'm not really sure how much I should invest into this old machine, or how fast I would "outgrow" it. My business is mainly engineering but I do love making things and try to keep that at least 25% of my business, I have a small shop with a couple other small cncs and prototyping tools. I have current projects that could absolutely benefit from having a 5 axis table, so I think that may be one motivator to get another machine in the shop in the future.
The current condition of X and Y:
- The Y ways look pretty clean, I haven't peeked at the turcite yet. I measure a deviation of .0012" (right side) and .0027" (left) in the box thickness
- X ways look a bit rough, corrosion in the middle, and gouging at the ends and I measure a deviation of .0028" (back side) and .0013" (front) in the box thickness. The turcite I can see isn't great, and one side has a chunk missing, but isn't worn too thin and seems to be still attached. There are embedded chips I can see on one corner.
- Indicating off the table in more than a dozen spots after leveling, I have only .004" difference across x, and .001" in y at worst. The X and Y also ballscrew show very little backlash in the nut. I think this seems to be a good sign that the table had good oil delivery and wore relatively evenly over its life (compared to other people's fadals). The table has some .005"+ deep corrosion pitting under where they had 3 vices on the table so I would not be afraid to resurface it, if that's a good idea...
-the number on the table in the last photo were from indicating it prior to leveling, I saw about .001 improvement on both sides of table once level.
Last edited: