Thread: '91 Haas VF-1 Rebuild

So finally, my work schedule cooperated with the weather and I was able to get in the garage to work on this project. Two weeks ago I replaced the X-axis cable. Turns out that was a HUGE PITA! The factory cable is made as the machine is being assembled. The original cable has a nice 90° angle fitting that is first bolted onto the Y-axis gantry (I have no clue if this is the correct term). Then, the conduit and cable is ran as the machine is being assembled. This allows the connectors to be crimped on after all the wires are run. This issues with replacing this cable is that the hole in the Y-axis gantry is not large enough to pass the connectors on the X-axis cable. Also, the Haas replacement cable is one piece and does not feature the nice 90° angle to keep the cable from getting rubbed by the X-axis servo as it transverses past it.

First off, it was a pain to get the X-axis cable out. I ended up having to cut the cable just to get access from the extra large nut that hold the 90° fitting. Next, I quickly realized that the connectors would not fit through the Y-axis gantry. I had to cut a larger hole with a 1-1/2" hole saw....without the pilot drill bit. It was fun to say the least! Next the cable was run, and I electrical taped the crap out of the area that contacted the newly drilled hole, so it didn't cut or gouge the new cable. Next, I had to drill and tap a hole to add a hold down since I didn't have the factory 90° fitting that kept the cable from touching the X-axis servo.

After that debacle, I started rebuilding the way covers. I started with the rear Z-axis cover. It didn't need much, but it did need a cleaning. I tried to grind most of the deep scratches out of the covers that needed it. Next was the Y-axis cover. I cleaned the cover with a 180 grit flap disc and a angle grinder. After installing it, I quickly realized that rear rollers were not adjusted correctly. When I got looking, I saw that they were just bent to sh$!t! I bent them back into the original shape and installed the cover as well as a new wiper.

I them focused my attention on the tool changed. I had purchased new pie plates, covers, and springs. I assembled it and reinstalled the finished tool changer.

Next it was onto the X-axis way covers. Again, I cleaned them up with the same flap disc. I also pounded out any dents and straightened the covers as best I could. Last, I installed the new way wipers and tray that surrounded the table.


Pictures of progress:

I removed the rear steel panels to power wash them. They were sealed with some STRONG sealer. Does anyone know what this is and where to get it? I'll need some to assemble everything in a couple weeks.

Originally Posted by moparmuscl

I removed the rear steel panels to power wash them. They were sealed with some STRONG sealer. Does anyone know what this is and where to get it? I'll need some to assemble everything in a couple weeks.

Looking great!
I asked Haas about the sealer not long ago and their techs are using SikaFlex 1A. I also had the suggestion from BGL to use some 1/2 thick neoprene to fill in some of the gap in the back rather than fill it all with new sealer.

Steve

Originally Posted by BGL

I used only four tubes. Used lots of nitrile gloves though.
I Installed the base first and filled the big gap at the back with a scrap piece of closed cell neoprene. You will need to be creative at the sides of the Y axis, shape it so you do not cause a dam effect of the collant off the cover to the tray.

I believe they use Sikaflex1A to seal all enclosure panels. Really does the job, but it can be messy and does not wash out of clothes.

Missed it by that much!!

Looking good, keep it up!

I ordered the Silkaflex last week, but it hasn't come in. I think all I have left to do it finish the front way y-axis way cover. I got 75% it done today. I figured I'd detail the process since I had a PM regarding the process of replacing the wipers.

I start by using a 120 grit flap disc on an angle grinder and lightly clean up the top surface. This gets the old wiper rubber hot, so I then use a pick and dig it out. From there I use an expanding snap ring pliers to expand the metal holder for the rubber. After it is opened up, I use a wire wheel to clean the grove out. The new wiper gets cut to length and installed in the groove. Next, using a punch and hammer, I hold the wiper securely in place and hammer the existing dimples where the old wiper was secured with. Then, I hammer down the entire length of the metal. After that, I use the punch and make some extra dimples to help fasten the wiper. The rest of the way cover gets the 120 grit treatment followed by a surface finish using a Scotch-Brite pad.

I've also been slowly adding machining tools to my collection for when I get started. I picked up a used Tapmatic Syncroflex rigid tapper today for ~$80 shipped to my door. I was pretty stoked considering that costs $600-650+ brand new.

I'd like to change the transmission gear oil. Since this is made prior to Jan of '92, it does not have a gear pump; it's an oil bath and specs Mobil SHC 600 or equivalent oil. The Mobile SHC 600 series come in several different weights. What weight is correct?

Also, for a small home DIY guy like me, where is the best place to source coolant and way lube? Thanks guys!

So, I started another thread about Haas 'lifetime' gear oil on the pre January 1992 VF1/2 machines (maybe more). The thread is below:

'91 VF-1 Lifetime Gearbox Oil???


I have NEVER believe in lifetime oil in ANY application, so I decided to try and find a way to change it. I pulled the drive motor off to have a look. I was not able to disconnect all the wires because two were soldered on, so I set it on top of the tool changer arm and secured it using a strap. This left the transmission directly exposed....and I was SHOCKED!!! The transmission is almost BONE DRY. The orange film in the pictures is oil (Mobil SHC 600 series is orange), but it is a 1/32" film at best. I don't know how this thing stayed together!!! I have to guess that it has a bad seal somewhere, so my plan is to drill and tap a fill and drain port in the side of the transmission. This will allow me to periodically replace or just add as needed. This will also allow me to buy some cheap oil and flush the gearbox to remove anything that is in it. I will probably run a couple gallons of cheap oil through it to be safe.

The Haas repair manual calls for Mobil SHC 600 gear oil. My problem is that Mobil makes a SHC 600 series oil, that varies in viscosity. Haas has no clue what exactly was put in it from the factory. The SHC 600 oils can be found in the link below:

Mobil SHC 600 Series


The Haas mills after Jan of 1992 use a larger capacity cooling system with a sump and a pump. This uses Mobil DTE 25 hydraulic oil which is a ISO 46 grade. I'd think I need to go heavier than that due to the gears needing splash lubrication and gear 'cling' to lube the transmission. Anyone agree or disagree? Any comments or concerns? I need some help figuring out which Mobil SHC 600 series oil is right.

I decided to pull the tool changer piston off and look at the belt. Looks like I found out where the .999 quarts of oil went...

I guess I'll call Haas tomorrow and see if they have the seal available. If they do, I'll pull the tranny and do it right. That will also allow me to clean the belt area and easily replace the belt.

Unfortunately, all that oil and sludge in the area of the spindle belt is somewhat normal. It is produced because of the coolant mist that is created during the machining process. This vapor goes everywhere (and I mean everywhere), the water from the mist evaporates and leaves an oily film. Over time this film becomes more and more and you get what you now see.

Not saying you don't have a leak, but a lot of oil in this area is common. The spindle fan tries to exhaust hot air out of the head covers, but in doing so also sucks contaminated air in. Some people will reverse the direction of the spindle fan and say it keeps the items behind the head covers cleaner and still cools the motor just fine; your call though.

Good idea for a fill and drain plug. I don't believe in lifetime oils either.

Originally Posted by haastec

Unfortunately, all that oil and sludge in the area of the spindle belt is somewhat normal. It is produced because of the coolant mist that is created during the machining process. This vapor goes everywhere (and I mean everywhere), the water from the mist evaporates and leaves an oily film. Over time this film becomes more and more and you get what you now see.

Not saying you don't have a leak, but a lot of oil in this area is common. The spindle fan tries to exhaust hot air out of the head covers, but in doing so also sucks contaminated air in. Some people will reverse the direction of the spindle fan and say it keeps the items behind the head covers cleaner and still cools the motor just fine; your call though.

Good idea for a fill and drain plug. I don't believe in lifetime oils either.

Maybe a tall, vented fill tube?

Mike

So I called Hass this morning. They don't offer just the seal....go figure. I guess I'm going to have to take the transmission out and measure the shaft OD as well as the ID of where the seal gets pressed into. Hopefully I will be able to find a seal vendor that can sell me one. I don't think I have an option on this, because since was run dry, I'm sure the seal is extra crispy do to heat.

I'm tearing apart the gearbox and I'm running into troubles, so I need some recommendations. I can't get the top pressed on piece of the gearbox. I have tried to use a standard puller that pushed against the shaft and I flared it out about .010". I rigged up another system where I am pushing against the top plate, but no luck there either. I have heated it with applied force and nothing. Anyone know of some slick tools or tricks to help? It HAS to come apart because the lower bearing that supports the low gear load is shot due to lack of oil.

Finally figured out the trick. It's a tapered fit that compresses the inner sleeve to create more of an interference fit. I had to make longer bolts to screw in, but after I did that, I was able to press the two apart, then use the lower shoulder to press the upper piece off. I think I found the reason the transmission started leaking bad. It looks like air piston's (that shifts the transmission) seals got old and dried out. This let the oil leak by and out the bottom. The piston actually had an ounce or so of oil in it as well as the lines to the solenoids. The shaft that has the sliding gear on it had the snap ring that supports the weight of the shaft onto the lower bearing. When this came loose, the upper bearing that sits in the top cover slid down about 3/4"-1". That meant to only bearing to take all the loads was the lower bearing. Also, the main shaft that drives the lower belt has a lot of wear on it from the inner bearing race. There are two issues. One, the shoulder is worn about 1/6"-3/32" and the OD of the shaft is worn so the bearing fits slightly loose. I'm not sure how I'm going to rebuild that. I guess I'll have to look into tig welding new material onto it and have it machined back down to the original dimensions. A couple of the gears show some wear, but I think they will be just fine once it is back together with new tight bearings.


For anyone that wants to tackle this project, here are the numbers I got of the bearings and seals:

Main output shaft
Bottom bearing --> Nachi - 6306NSC
Bottom Seal --> Repco - PR9193
Top bearing --> MGM Radax - 6204 RSR
Shifting shaft
Bottom bearing --> Fafnir 303PP
Center bearing --> Fafnir 9105PP
Locking nut --> Bearhug - BH-05
Top bearing --> Fafnir 303PP

Upper groove's snap ring was popped out








Shift shaft oil sealing o-rings that hardened and started leaking








Snap ring that popped out





















Wear on main output shaft

That's a strange wear pattern on the shaft.It almost looks like someone knurled it to restore the fit(which usually doesn't last).

Originally Posted by ratbldr427

That's a strange wear pattern on the shaft.It almost looks like someone knurled it to restore the fit(which usually doesn't last).

Great call!!! I thought it was weird, but I couldn't put my finger on it. That makes prefect sense! If someone was in the gearbox, that would also explain the snap ring out of place.