833TV Side projects day.

[Christianstark]

So I am in the midst of making parts for my Phil Vandellay belt grinder, and am at the table. I really want a nice flat table with a great surface finish, so I have decided to confirm tram. Before I did that though I wanted to check my Z-Axis gib as locking the head is spongy feeling. Lowered the head so the spindle nose is gently resting on a chunk of aluminum, and removed the gib. Stoned the back side of the gib to remove the raised areas due to locking bolt ramming into the gib at an angle, and decided to try something better. Ground down a brass rod to a matching angle, and bored out 4mm in the back. Machined the locking bolt to a nice slip fit on the brass grub, and have one more to go. Ill take pics of the second one.

If this does not help with locking feel, I am going to mill 2 landing spots into the gib at right angle to the locking mehanism, or do something with a ball nosed end mill and bearings.

Edit 2 - Scratch the ball nosed end mill Idea. Id lose gib adjust capabilities.

Edit 3 - OR wouldn't I...

 

[Christianstark]

I am really struggling getting the head trammed. There is a nod that I can get to go away by locking the head, however, when I lock the head it throws off side to side tram...especially whin I clamp down on the top locking handle. The head cants counter clockwise when I cinch down on the handle to clamp the gib. but removes the nod. The gib is already in quite a ways so I don't think advancing the gib further would solve this issue, and clamping is still a bit spongy, especially the top locking handle.

The nod is about 7 thou over 6 inches and when I clamp the top to remove the nod, the side tram is off about 10 thou or more over 12 inches.

How can I get this under control?

 

[tq60]

You have something sloppy.

Simply put, you have 2 mating parts that are not a good fit.

Is it rocking on a high spot?

Some photos may help, the locking parts maybe.

When you lock it the tilt changes, imagine to disk brake rotors back to back with a large bolt through the middle holding them together with a couple clamps at the edge to be your lock.

If you put a couple grains of sand between them they can rock or pivot on those grains of sand or high spots.

If the center bolt holding them together is loose they are not really together until you lock them.

Either way it results in movement.

A dial indicator helps.

Look for movement between parts as you apply lock.

Sent from my SM-G781V using Tapatalk

 

[7milesup]

When I had my 833T, the Z-axis gib was not thick enough to actually tighten the head up. Initially, it seemed as if it was doing its job, but after removing the bottom gib adjusting bolt, I discovered that the gib would stick out of the bottom by 1/4" or so. I would recommend taking the bottom gib adjusting bolt out and seeing where you end up with a snug fit. Does the gib tighten up before reaching the bottom gib screw? Or does it protrude past where the bottom gib adjusting bolt would be? That is where I would start. If the gib protrudes past the bottom gib adjusting bolt, some shim material may be required, which would need to be placed between the gib and the z-axis locking levers.
I know that there were a few of us that had this issue.

 

[Lucas E]

When I had my 833T, the Z-axis gib was not thick enough to actually tighten the head up. Initially, it seemed as if it was doing its job, but after removing the bottom gib adjusting bolt, I discovered that the gib would stick out of the bottom by 1/4" or so. I would recommend taking the bottom gib adjusting bolt out and seeing where you end up with a snug fit. Does the gib tighten up before reaching the bottom gib screw? Or does it protrude past where the bottom gib adjusting bolt would be? That is where I would start. If the gib protrudes past the bottom gib adjusting bolt, some shim material may be required, which would need to be placed between the gib and the z-axis locking levers.
I know that there were a few of us that had this issue.

You could also cut the end of the gib off so it will adjust further without making out the stop screw. Or contact PM for a new oversized gib.

 

[7milesup]

You could also cut the end of the gib off so it will adjust further without making out the stop screw. Or contact PM for a new oversized gib.

Yes, I actually did cut my gib off, but after doing so, I received feedback from the H-M membership that it was not the route that I should have taken.
Anyhow, I sold the mill this summer and now have a very large Sharp knee mill in my shop, so this is no longer an issue for me.

 

[Christianstark]

When I had my 833T, the Z-axis gib was not thick enough to actually tighten the head up. Initially, it seemed as if it was doing its job, but after removing the bottom gib adjusting bolt, I discovered that the gib would stick out of the bottom by 1/4" or so. I would recommend taking the bottom gib adjusting bolt out and seeing where you end up with a snug fit. Does the gib tighten up before reaching the bottom gib screw? Or does it protrude past where the bottom gib adjusting bolt would be? That is where I would start. If the gib protrudes past the bottom gib adjusting bolt, some shim material may be required, which would need to be placed between the gib and the z-axis locking levers.
I know that there were a few of us that had this issue.

My gib will protrude out the bottom about half an inch, it does not just drop into place though. If I lower the head and rest the spindle nose on aluminum in my vise, I can move the Z knob back and forth a quarter turn and the gib will continue to drop into place. It was sticking out a full half inch by the time the top gib adjust bolt started to hit tension.

 

[7milesup]

My gib will protrude out the bottom about half an inch, it does not just drop into place though. If I lower the head and rest the spindle nose on aluminum in my vise, I can move the Z knob back and forth a quarter turn and the gib will continue to drop into place. It was sticking out a full half inch by the time the top gib adjust bolt started to hit tension.

I believe that may be your problem or at least one factor in the issues with getting your mill trammed in. It certainly is not the way it should be. There should be some adjustment force placed upon the gib with the adjusting screws otherwise, you're not getting a snug fit. This is especially true on the z-axis because it naturally wants to nod because of the head's weight.
When I did call PM about this issue, I was essentially given the run-around. I believe I talked to John there, and he said that every gib is fit to a particular machine and blah, blah, blah. Obviously, this is complete BS because if that was the case, I wouldn't have my gib hanging out of the bottom of the way. They wanted $50+ for a new gib, but I decided to shim mine, which seemed to work.

EDIT: You are not the first nor the only person to have gib issues on the 833. I believe there might be a thread on here about this issue.

 

[Christianstark]

I believe that may be your problem or at least one factor in the issues with getting your mill trammed in. It certainly is not the way it should be. There should be some adjustment force placed upon the gib with the adjusting screws otherwise, you're not getting a snug fit. This is especially true on the z-axis because it naturally wants to nod because of the head's weight.
When I did call PM about this issue, I was essentially given the run-around. I believe I talked to John there, and he said that every gib is fit to a particular machine and blah, blah, blah. Obviously, this is complete BS because if that was the case, I wouldn't have my gib hanging out of the bottom of the way. They wanted $50+ for a new gib, but I decided to shim mine, which seemed to work.

EDIT: You are not the first nor the only person to have gib issues on the 833. I believe there might be a thread on here about this issue.

I got a similar response with my call yesterday. Not bashing here, but when the product page talks about the machines quality over its competitors, and then I get told on a call that I need to temper my expectations with the machine, it kinda ticks me off a bit. Maybe I am wrong. I am about as low experience as they come, but I don't feel like I should have to lock the head to solve for 7-8 thou nod, and then IF I indeed do, and that is indeed normal, I shouldn't be introducing 7-8 thou of counterclockwise tram error to X when I do. PERIOD.

I'll put this out there now as a challenge to whomever reads this at PM. There is a WORLD of difference dealing with Matt on something, and dealing with someone else at the company. This gap should not exist. I am not saying I have not gotten annoyed by something when dealing with Matt, but I will say I never felt like he just threw his hands up in the air, and told me things are what they are.

Ill look online today for some shim material. Would you recommend brass, or something a bit harder so it does not get galled by the locking screws as easily?

 

[Lucas E]

You shouldn't have to pay for an I'll fitting gib on a machine that is under warranty. PM sent me a new gib for my Y axis that didn't fit properly without charge. Although I agree, they don't come right out and offer to make things right immediately, you have to press the issue.