Table Resurfacing???

[mniadna]

I just purchased a 4020 HT. The machine is in good condition except the table is worn. Is there any way to resurface the table while it is on the machine? If I can't find a resonable solution, I think, I am just going to mount an aluminum sub plate to it.

Thanks,

[Delw]

How bad is bad? is it just lots of crash marks and people not paying attention marks?
or is it from a rebuild and the table is not flat?
Your machine should have a resurfacing program in it. I have it on my machine if you need it I can send it to you.
I never used it but have seen it in the program list along with a host of other sub programs. it makes those coining marks that are on the table.

if your running parts and using your table for location its best to use a sub plate, however if your just gong to use vise's you dont need to.

when I used a subplate I used 2. the 1st one was 1.250 thick alum plate and then I used a 1" one on top of that as a throw away, ( one that I could actually drill holes cut into when running flat plates and such) this way I didnt damage the main one.
you can get away with using 1/2 or even 3/4 but on a 36"-30" plate its better to use a thicker one for the throw away plate.

if the jobs I am doing is small, I use smaller sub plates on top of the main one as its much cheaper.

the main sub plate could have a few pin holes and screw holes in the plate for location of fixtures which will make it much eaiser to set up and your able to fin position extreaml quick as those locations wont change.

Delw


Delw

[denmar]

Check under the table for loose or worn out TUCITE.

[gsrmmeza]

The shop where I work had a machine table recut and it takes 2 special tools. The first is a 8 inch fly cutter and the second is the tool for putting in the scales. The fly cutter has 1 round insert and is 8 inches so that it can cut all the way to the edges of the table. The scaling tool has 2 scrapers but only one was used at a time. The program scraped everything but a narrow area then the second scraper was used to finish.

[gsrmmeza]

I hope this works. Here are the videos of the table being cut and the table being scraped/scollaped.

YouTube - Fadal Table Facing

YouTube - Fadal Table Facing

YouTube - Fadal Table Scraping

YouTube - Fadal Table Scraping

[mniadna]

Thanks gsrmmeza! I'm assuming those are home made tools. MSC sells large twin cutter fly cutters. Maybe I will give that a try... I'm going to check my spindle perpendicularity first, though.

[mniadna]

Table isn't that bad. It is crowned maybe .002. The table has a decent amount of wear and its fair share of drill marks. It came out of a sprint car shop. It looks to have low hours, but a lot of steel parts slid on and off the table.

[HuFlungDung]

I wouldn't bother machining 'use marks' off the table. It just makes you paranoid and leads to a lot of frustration when you put your own 'use marks' on the table

The only reason to remachine the table is because somebody tried to remachine the table and botched it slightly because they didn't have the necessary experience.

[gsrmmeza]

The tools belong to Fadal. They were doing a PM on the machine and the table needed to be recut so they did it. The back center of the table was Z0, the front right was Z-.0055, the front left was Z-.0057, and front center was Z-.003. The table sagged towards the ends and to the front. This machine was built back in 1989 so it's had alot of use.

[Delw]

gsrmmeza

Thanks alot for posting that, I was alway curious how they did the tables and got that finish.

Delw

[Konstrukter1]

Great post!

I was always wondering how they do that.

What is on the botom? HM?

[ThatguyDave]

This post definately answered the questions that a bunch of us try not to dwell on.

As far as turcite wear under the table goes, it'll be real interesting to see just how worn my machine is in comparison to this one. I'm guessing that when I get my machine under power and leveled it'll show that the front of my table dips down as well. I see more pronounced wear on the front turcite but since I have no frame of reference its kind of hard to tell if the wear is normal or significant. Fortunately the turcite isn't peeling so the table is going right back on the machine once everything is cleaned up and the oil regulators work to my satisfaction.

My work table looks pristine so any wear is probably 99 percent from turcite loss. The ways are pitted but in otherwise good condition as well.