Z axis (knee) power feed recomendations

[alloy]

I have a Kent 4VK mill that's about 3200lbs. About the size of a series II Bridgeport and am looking at a power feed for the knee. Sales have been good lately and I'm tired of cranking that heavy knee up and down all the time. I would rather work smarter than harder any day as I spend a lot of time lately on my mill.

A Servo brand is out of the question at $1200 so that leaves import brands. I've read a lot about them and have seen quotes that they are just as good as the Servo brand feeds. But I don't know the people that posted that and wanted to ask here where I trust people to help me spend my hard earned money.

The knee is pretty heavy and all I've seen are 150lb torque feeds. I'm not sure id there are 200lb ones or not.

I welcome your comments.

Was looking at this one on Ebay.

http://www.ebay.com/itm/Power-Feed-...474773?hash=item1eb3dab915:g:0xQAAOSwCEdYUBzo

 

[Holescreek]

I make my own version of this drill adapter for my mills and use a 1/2" corded hand drill to spin it. If I'm just drilling I leave it set up and raise and lower the table as needed. If I'm milling I slip it off and put the handle on for fine adjustments. I've made the adapters for other style mills for a friend, it's just the concept of using a drill to do the hard work.

http://www.ebay.com/itm/Bridgeport-...754398?hash=item1a23eb049e:g:jHQAAOSwopRYfYSU

 

[Rick_B]

I've got one of the adapters that holescreek showed (not sure if it is his or not). It works great and is a reasonable alternative to a power feed - in my opinin
Rick

 

[Terry Lingle]

I made a power feed for my mill from a 1/2 inch electric drill and a couple of chain sprockets to reduce the speed by a factor of two.
it is hard mounted with the drill back along the "tube that the raise shaft runs in. I made an extension for the hand crank so I could use it for fine adjustments.
Caution if you do this be sure to remove the hand crank from the operating position when you are not using it.
The drill trigger was replaced with a remote forward- off-reverse switch and a dimmer used as a speed control.
Before I started fabricating I tested using the drill to drive the table raise /lower directly and found that it would overload and try to release the magic smoke at low speeds.. The drill is a Milwaukee 1/2 inch 800 rpm model IIRC and with the 2:1 reduction it is not overpowered.

 

[talvare]

I made one for my BP a few years ago. Purchased a gear head motor, sprockets and chain on eBay and fabricated the rest of the pieces. I made it with an adjustable clutch so that it can be set so that nothing gets damaged if I get stupid and run the knee too far in either direction. Also, the clutch can be completely released with about 1/4 turn of the hub (shown in the photo with the handle in one of the holes) and the knee can be operated manually with a 1" socket and ratchet. It works very well and I think I've got less than $100 invested.


Ted

 

[Holescreek]

How do you make fine adjustments for milling with power feed units? I haven't seen one that has an extension shaft for the crank handle.

 

[Terry Lingle]

on mine I machined an extention drive that has the driven sprocket melded onto it the regular crank handle fits onto the extension the same as it used to fit on the knee drive just be sure to remove it before you use the power drive. I have a chain gaurd on mine so it is a little complicated to get a picture of the drive extension but I will take a couple of pictures of it with the original drive handle in place.

 

[Holescreek]

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.



I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.



Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544

 

[alloy]

I picked up one of those adapters. Its for sale cheap now. Only used once.

My Milwaukee fuel 1/2" drill doesn't have enough power to lift the knee.

 

[Kroll]

Like the adapter ideal,if you can find one of those older American made Milwaukee Angle Drills I bet it will have enough torque to raise/lower the knee.Plumbers would use these drills with screw type wood bits to punch holes for pipes.And it being angle drill it would not stick out as far as the other drill.Just another ideal----kroll