Kalamazoo 7AD Hydraulic Feed

[donf]

I purchased a 7A bandsaw from an estate a few months ago for $150. I like it better than my Harbor Freight Saw and its a little bigger, but it's in need of some help. It came with a few spare blades, good thing because every once in a while the hydraulic feed just slams down taking the blade teeth with it. I have ruined two blades in three months. The downfeed changes, with the same setting. Sometimes its very slow and other times its almost free fall. It does leak a little out of the bleed hole too. So before I ruin another blade, I better do something about it. I got the free pdf from Clausing and they have parts in stock. My question is there is a new replacement cylinder on ebay that people seem to be buying a lot of, but they only warranty it for 30 days so they can't be too sure of their product. Is it wiser to just start fresh? My cylinder looks like it had some problems and was brazed on. I know nothing about them, this will be my first overhaul if that's what is needed. Maybe there is a third option? I posted here about 7 years ago for my lathe rebuild and got a lot of useful insight.

[duckman]

I would take it apart and see if the check valve attached to the piston has some crap stuck in it , or when they brazed it did they remove the piston and when reinstalling it did they take a piece out of the piston seal so that it only seals some of the time. JM$.02W

[cijuanni]

Fix the Kalamazoo, they are pretty simple and the stock setup works well so long as you don't wrench on the tiny flow valve.

[alsinaj]

I just renovated the same model saw, with the same problem. Great saw except for the so-called "hydraulic feed," which is actually not a "feed" at all. Feed pressure is regulated by the spring at the rear of the saw. Test it by gently lifting the frame off the bed with a fish scale. Regulate the spring to 8 pounds if cutting dry, 10 lbs if cutting wet.

The hydraulic cylinder is there for one purpose only - to prevent the blade from plunging rapidly when cutting through thin wall tubing. I wasted much time and money trying to get the original cylinder to behave properly. New factory parts from Clausing did not fit -- probably because of minor variations over the years. Neither did a new piston and seal I fabricated myself, which revealed that my cylinder was not cylindrical - the ID varied over the stroke, and it was oval in different places. I could never get it to behave consistently. I also tried and failed to find a new hydraulic cylinder that would work, but couldn't find one with dimensions that would not interfere with the motor or the workpiece in certain positions.

The good news is that unless you intend to cut thin wall tubing all day long, there is an easy solution. Throw away the hydraulic cylinder, mount a drawer handle on the front end of the frame, and when you do cut tubing, control the downfeed with your hand. Works for me. Wish I had just junked the old cylinder right away instead of trying to fix it.

[donf]

Thank you for the feedback. I dont cut thin wall all day long, it's a hobby saw for my garage. When I do use the saw, there is a good chance that that is what I am cutting though. eBay does have a new replacement, not oem but searching "Kalamazoo Style Universal Feed Cylinder" will find it. They have sold a lot so I figured others may be having trouble rebuilding their originals too. The 30 day warranty is sort of scary, that's like a used car dealer. No faith in their product I guess. So far its thin wall tube thats ruined both blades. I make several cuts and it behaves fine then I get lazy and don't have my hand on the saw and it plunges taking the blade teeth with it. I will pull mine apart and measure to see if mine is worth rebuilding or out of round.

[Edwin Dirnbeck]

.

The hydraulic cylinder is there for one purpose only - to prevent the blade from plunging rapidly when cutting through thin wall tubing. fix it.

I disagree,The cylinder is there to smo0th out the downward movement. It is helpful on every cut. I allways turn the blade on about 1/4 inch or so above the stock and let the cylinder smoothly engage the work.The cylinder also keeps the blade from grabbing when the last bit of cut is about done. I would buy a replacement cylinder and don't worry about 30 dyt guarantee. ,its only a simple cylinder,it should last forever. I have fixed a few kalamazoo saws . None were worn out. All were damaged by some incompetent swine. Edwin Dirnbeck

[Edwin Dirnbeck]

I would take my time and fix it right you won’t regret it here is mine


Sent from my iPhone using Tapatalk

[wdtom44]

I got mine to work, I don't remember if I made a new piston or modified the old one. Possibly I modified the old one as I think I remember having to drill bypass holes to make it into a check valve. Seems like the one from Clausing was expensive, as much as you and probably I paid for the saw. I would take it apart and see if there is a worn out O ring. If you decide to go with a new cylinder you might try an air cylincer. They work the same except they aren't made for as much pressure as a hydraulic cylinder however the pressure in this "system" probably isn't over air system pressures. Air cylinders are available in a wide variety of sizes and styles, look in McMaster. And you can get a flow control from them too that will screw right on, you want one that regulates the flow in only one direction. Using a cylinder a little larger in dia. will reduce the pressure, and because you are flowing more oil for the same movement it will not be as sensitive to to the flow control settings. If you used or ended up with a longer overall length cylinder you could always lower the lower mount, a new lower mount from a frame extension on each side of the saw frame would be simple. I have always been going to use the 1 1/4" bore (I think) air cylinder I have for this but my repaired one works most of the time and I have other things I want done more. One thing some may not realize about this saw is that they had a leg you could put in the saw frame extending out the back so that after you disconnected the hydraulic cylinder you could raise the saw up to vertical and use it as an upright like the 4x6" imports. The manual shows this option and there is nothing one couldn't make if you wanted to.

[Mike Amick]

Heck .. my HF 7x12 has that, and it works amazingly well. I only wish the control valve was in a handier place because i like
to get the saw close to the work before engaging it and I have to lean way in to activate it.

[donf]

I took it apart. It is simple. The leather seal actually doesn't look too bad. The saw came from a community college and it looks like someone took it apart and left out the spring seating the check valve in the piston. Without that, the ball can just fall with gravity. I think that's why sometimes it works and sometimes it just falls. The shaft has some score marks on it and the cylinder is goobered with braze outside top and bottom. So I will ask about cost from Clausing before deciding on what to do. I do see what someone said about the main piston seal not fitting. It looks like they revised the drawing at sometime. I will ask if they have a seal that works for my saw, otherwise the simplest thing is to buy the new replacement.

[mickeyf]

when you do cut tubing, control the downfeed with your hand

I do this with my 4x6 HF as needed, but it does mean you can't just walk away and let the saw do its work.

[bandsawguy]

Clausing is very proud of their parts. I mean very proud. I would look for cheaper off the shelf parts that can be retro fitted.

[donf]

I was able to repair the original cylinder for about 28 dollars in parts and shipping from Clausing. The piston seal and head they show is not what mine had and would be very expensive as a lot of parts had to be changed to later versions. Lucky my leather seal seems to be OK. I replaced the upper seal that was leaking and the missing bypass spring. It works smoothly and no sudden drops. Thank you to all who commented.

[wmgeorge]

This is a old, old Thread I know but does anybody have a download link for the manual? I would like to use as a vertical saw, anyone tried that attachment???

[mickeyf]

I am 87% through fixing up an 8A, and the manual I have also seems to cover the 7A. I don't recall where I downloaded it from, but if I can't find the URI I could email you a copy of the PDF I have. However, I don't recall any mention of using any in the manual as vertical saws.

I recently got rid of my 4x6 and replaced it with a like-new 7x12: https://www.kmstools.com/magnum-indu...t-drive-147412

The hydraulic feed on this one really does control the down-feed, and is much more adjustable than the original cylinder on the Kalamazoo. I'm even toying with the idea of replacing the one on the Kalamazoo with one of these : https://www.amazon.ca/Hydraulic-Cyli...PS/ref=sr_1_15

If I do that I'd run tubing up to the control end of the saw so that the adjustment knob was handy to the other controls, no longer attached to the cylinder itself.

The manual I have is not quite the same as this one: http://vintagemachinery.org/pubs/detail.aspx?id=15218

You might want this one: http://vintagemachinery.org/pubs/detail.aspx?id=4934