1994 VF-2 cleaning/rebuild

Hi guys, first post here. I bought this haas for a 1000 bucks and got it into my tiny shop awhile back. Just got power to it and every thing seems to work except tool changer (have not tried it yet)which was surprising since it sat for 5 years with out power.

Started cleaning it this weekend. pulled the way covers off to find shavings every where under them, especially under the y axis, filled a shopvac. lucky it was all brass, no steel or stainless whatsoever. x axis wire conduit is broken in the usual so i ordered some from mcmaster to replace it. gonna order some new way cover seals tomorrow and do a little rework on the way covers, they are pretty rough. Ball screws seem ok, was getting about .0002 backlash on all axis.

The linear guide bearing block seals on all axis are shot and really need to be replaced. looks like i will need to remove the bearing blocks to do this.
Anybody here ever replaced the seals before?

Also have new oil lines on order from mcmaster.
Ill wait till the oil line and the wire conduit comes in and replace those, then figure out what I can do about the linear rail bearing seals, then rework the way covers.

The last VF I worked on I found every single linear rail bolt needing to be torqued or replaced. Pull those plastic plugs and check those bolts on the rails.

Do the rails have to be realigned if the bolts are loose?

ewlsey said:

Do the rails have to be realigned if the bolts are loose?

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The linear rails have a machined edge that they use for location and the opposite side has a concentric bolt to keep it tight to the machined edge. Shouldn't be an issue especially if you remove and replace one at a time.

Thanks for the tip on the rail bolts being loose, didn't even think to check that.

Anybody see anything wrong with un bolting one linear rail truck at a time and sliding it off the end of the rail to clean and inspect it? Maybe replace seals if i can find some.

ZWelds said:

Thanks for the tip on the rail bolts being loose, didn't even think to check that.

Anybody see anything wrong with un bolting one linear rail truck at a time and sliding it off the end of the rail to clean and inspect it? Maybe replace seals if i can find some.

Click to expand...

If you remove the truck off the rail, 90% of the time all of the roller bearings will fall out of the truck. I would not recommend doing so. unless you order new trucks... It is a manual grease system, it looks like it was over pumped a few times. The MFG of the rails might sell the "seal" or wiper. try to just replace that when the truck is still on the rail.

Good Luck!

Wish I could leave the trucks on but I have to remove at least one truck per rail to get to seals on inside because there are 2 trucks per rail

nice work tearing it down are you also going to rebuild the transmission from hi to low gear, or is that working fine. Im also selling our old haas for 1k. Might just keep it as a hobby machine,Good stuff man

Yeah I do plan on tearing into the gearbox, its pretty loud. Figured I'd save that for last.

So it looks like I have THK HSR 35 rails on X and Y. NSK LY 35 rails on Z.

I will be giving both of them a call tomorrow. Hopefully they can sell me some wiper seals.

When taking the linear bearings off the track you need a short piece of service track butted up the the rail to keep everything together. Slide it off the machine rail and onto the service rail.
Check the spindle bearings first. My VF-1 made noise when I got it. The seal on the end of the cartridge was gone so debris got into the lower bearing. You have to change them as a pair.

Slow down!

You got 0.0002" back lash?? What are you expecting?

Seriously - you want to go through the nightmare of replacing rails and bearings?

What makes you think the seals are bad? From the picture they look typically dirty. I have a '92 VF-0 machine that was road hard and put away wet for years; it had a similar funk I removed with a cut off popsicle stick, WD40 and a tooth brush. The "seal" is nothing more than a thin piece of steel that fits very close to the rail profile. If it was completely gone so what? You want to make parts or spend the next six months and $$ making it perfect, why?

Just get a gallon of WD40 or equal w/spray bottle, popsicle sticks and a case or two of paper towels, 0000 steel wool for the serious gunk. Chisel off gunk with stick, spray, wipe, repeat.

Clean your oil reservoir [NO solvents] manually operate the oil pump over and over while inspecting each bearing, if oil is getting there your good, otherwise back track the line to the problem, unless the line has been damaged or the oil grossly ignored you should have no problems.

Take apart the axis thrust bearings - buy a proper set of hook spanner wrenches first! Clean, inspect and grease. If brush motors remove brushes and vacuum out the housing - or send them out to a specialist with the money saved by not getting new rail bearings.

Clean this puppy and get the tool umbrella and changer working and inspect the gearbox, repair it if needed, yea they are noisy out of the box, straight cut gears at high speed - noise is what they do. Draining the oil can tell you a lot, either no oil or oil that looks like metallic flake paint.. take it off and tear into it, otherwise fill'er up and run it.

Clean up and install the way covers, dry cut slow and careful some shapes such as milled holes, squares and hex. Measure them and if you have issues go through the simplest fixes first like changing the backlash comp parameters.

Seriously, you will have a great machine in no time for little cost and have learned a lot - I sure did.

PS. Everything you need to know is on here and in the manual - Good luck!

Thanks for the advice and Lol, definitely was not complaining about the backlash. I'll have to get a better pic of the linear rail wipers. They are definitely shot and will allow anything that lands on the rails into the rail trucks.

thk has the wipers for $6 apiece which is worth it for me. Those will work on x and y axis. For the z axis I'm still looking. Hopefully Haas can, my hfo is looking into it now, also should be sending out the way cover seals today.

Have some real fun and put some monster rails and bearing in there with some good preload.

Hey guys, got the linear bearing trucks on x and y cleaned and new seals installed. Cleaning was pretty easy. Slid them off one at a time and completely disassembled them. They definitely needed to be cleaned.

Started messing around with the x axis way covers. Some of the covers have deep pitting from corrosion. Decide to try fixing one, and it turned out pretty good. Used a flap disk on a grinder to remove most of the pitting. Then filled in the rest with stainless filler with my tig welder. Hit it with the flap disk again then an orbital sander and looks good as new!

More pics

You're a brave man. Most guys would't take the trucks apart for cleaning.

Just out of curiousity did you mic the balls? Not sure if your trucks are like this, but sometimes slightly smaller balls are in between the correct sized balls for spacers. I've heard of this in ballscrews.

Did THK give you instructions or pointers when you talked to them?

Good luck with the project!

the bearings are easy, just takes time.

Filling the pitting and making the cover beautiful - that is skill!

Good work!

Didn't mic the balls, kinda wish I had now lol.

Thk didn't give me any help with taking them apart. After I purchased the end seals I tried to get the side seals but made the mistake of letting them know it was for a Haas. They refused to sell anything else to me lol.

Thanks for the compliments!

Never mention Haas or the part # on the item for any part you search for outside of the HFO. I made that mistake when trying to get brushes for my shuttle motor. With a bit of effort I was able to figure out the part # for them through an online vendor, got them very reasonable cost. I would have gotten them through my local HFO if they would respond in a timely manner, good thing I have low overhead.