JET JTM-4VS-1 Knee Mill ~ Z-Axis Knee Powerfeed

[Scott(GA)]

I am trying to install a JET 350196 Z-Axis Knee Powerfeed on a JET JTM-4VS-1 Vertical Mill.

The Powerfeed came with a bracket kit for the Limit Switch assembly that seems inadequate. However, it wouldn't be the first time I've looked at something and missed the obvious. I was wondering if anyone had a JET Knee Mill with a Z-Axis Knee Powerfeed. If so, pictures of the Limit Switch Assembly would be appreciated.

Scott

 

[kd4gij]

I don't have a jet. But that power feed is just a rebadged import like Algin or Bestline. Post a picture of what you have and I can help. There isn't much force on the limit switch as it is activated by the spring plungers.

 

[Scott(GA)]

Here's an attempt to show where I think I'd have to put the channel that holds the Limit Switch stops. The machines I have seen Z-Axis installation videos of have a pretty good flat spot right next to the Knee. This machine has a more "organic" transition that makes putting the stops right next to the Knee problematic ...or at least I haven't figured out how to do it so far.

Link to a video of the Z-Axis Powerfeed's controls being exercised.

Scott

 

[Scott(GA)]

Bracket the Limit Switch is supposed to mount on.






An attempt to show how the Limit Switch would mount on the Bracket.






The Bracket included in the kit cannot bring the Limit Switch anywhere close to where the Aluminum Channel will hold the Limit Switches.


Scott

 

[JimDawson]

You could set it up like mine. The limit switch housing/cable is coiled up with a zip-tie around it and it hangs from the powerfeed. If you're a bit careful, you really don't need the limits. I just have a set of marks on my knee and column to tell me where the bottom is, I just stop before I reach bottom, and if I do need to go all the way to the bottom, I hand crank it the last 1/4''or so. The top is really no problem at all, you'll proabaly run into the quill before you run out of threads on the lift screw.

 

[Scott(GA)]

You could set it up like mine. The limit switch housing/cable is coiled up with a zip-tie around it and it hangs from the powerfeed. If you're a bit careful, you really don't need the limits. I just have a set of marks on my knee and column to tell me where the bottom is, I just stop before I reach bottom, and if I do need to go all the way to the bottom, I hand crank it the last 1/4''or so. The top is really no problem at all, you'll proabaly run into the quill before you run out of threads on the lift screw.

Jim,

Your approach does have merit... however, if possible, I try to make my stuff as "Scott-Proof" as possible.
Ha!

Best regards,

Scott

 

[mksj]

This was previously posted, the installs are pretty much the same independent of the mill brand. My mill has the channel raised on two round tubes with a bolt through the center. The switch is mounted on the knee. You should have gotten two sections of channel that are connected together to give you enough travel for the stops. The provided channel was flimsy, so I discarded it for a single piece of 80/20 aluminum channel. It is mounted the same way, the channel and stop bolts were slightly modified to fit the new channel.

Old channel with standoff spacer.


Fabricated new spacers and single piece channel.


Switch mount.

 

[Silverbullet]

I'd have not been smart like you and would have bought new limit switches and wired them top and bottom. Good job using what you had.

 

[Scott(GA)]

Thanks to all who have posted so far...

This JET branded item has a price that reflects some "added value" from the Align Powerfeeds (see LINK - it appears to be identical to the JET). It was one of the reasons I purchase a "JET" Powerfeed. I thought it would be delivered customized for a JET Mill.

I'm confident that JET is using a different Bracket to mount the Powerfeed on the machines that they ship with this option installed. That's one of the reasons I initially asked for a picture from someone that has a JET machine. I'll be giving JET a call today to ask about this.

 

[Scott(GA)]

I had a nice chat with Mary at JET's Metalworking Technical Support this morning. I explained my problem with the Limit Switch mounting hardware and asked if it would be possible to get pictures of how JET mounted this device at their distribution center. I followed up with an email

About an hour ago I got a reply email with 3 images of a JET Mill with the Z-Axis Limit Switch mounted. This confirmed my theory that JET had "special" brackets available for their distribution center's use.









I have sent a reply to Mary thanking her for the images and asking if the Z-Axis Limit Switch hardware would be available to someone (me) who had purchased JET Powerfeeds & a JET Mill.

I am hoping I will get an affirmative reply and this is what I would use to mount the Z-Axis Limit Switch assembly. If not, I am sure that I can replicate it but why reinvent the wheel?

Scott