Hydraulic Blade Tensioner

[Radar67]

Hello all,
     After seeing Woodbowl's tensioning system on his mill, I have decided to convert my Oscar 28 from manual tensioning to hydraulic. I would like suggestions for parts I could use to manufacture my own. I like the design of the Wood Mizer tensioner and think it would work. I'd like to hear what all the builders out there may have used on their mills.

[flip]

I used a small $30 ram from Northern hydraulics and a $25 single line master cylinder.  Look in my album, very simple and cheeeeap!  Just make sure ya use silicone fluid in it or else the seals will go bad fast.

Flip

[IL Bull]

My Burg Sawmill has a small hydraulic jack to tesion the blade.  The jack is designed to be used in the horizonal position.

[Percy]

Just a thot guys....The hydralic tensioners work great but need constant attention to keep the blade at the correct tension due to blade heating/expansion. If there is any way/room to use an air bag for tensioning, Id recommend it. The tensioning on my LT70 is set and forget and the design is as simple as a stick ;D

[D._Frederick]

I got the ram and pump used in the "Porto-Power" automotive system form northern toolhttps://forestryforum.com/board/index.php?action=position"> Note:Please read the Forestry Forum's postion on this company. You will have to adapt it to your mill and will need hoses and a pressure gage. Works quite well.

[Frank_Pender]

Don, why don't you pick up a set and come down and sho me how to put it on my Oscar 36. ;D

[Radar67]

Flip - I looked through your gallery and think that is a creative idea, seems real easy as well.

Frank and Don - I searched the forum last night and found pictures of a small ram, hose, and guage configuration. The way my Oscar 28 is set up (your set up should be similar Frank) either option should be an easy conversion. My current configuration is a big bolt that is hard to access. I'll try to send some pictures this evening.

Everyone, thanks for the responses, the little wheels in my head are turning a lot faster now.  ;D

[woodbowl]

  The jack is designed to be used in the horizonal position.

I've heard that laying a regular hydraulic jack on it's side is bad for it. What is it that goes bad exactly? Can it be taken apart and repaired?

[Radar67]

Hey Woodbowl,
     My step-father told me laying the jack on it's side caused it to leak at the upper seal. He wasn't sure if it could be repaired. I also read somewhere that it would not have the same amount of power in that position.

Stew

[woodbowl]

I also read somewhere that it would not have the same amount of power in that position.

Well........I know one thing. I've got a bunch of jacks laying around that only pump up for an inch or so and stop! I feel that the fluid is displaced somehow and hopefully would be an easy fix.

[Radar67]

Have you tried adding fluid to them? I have a couple myself and they both have a plug near the top to add fluid to them.

[DanG]

I tried using a bottle jack horizontally before, and all the juice fell out of it.  Just take out the little rubber plug and fill it back up.  It should be fine.

[Radar67]

I found a site that sells repair kits for bottle jacks, so there has to be a way to fix them.

Bottle Jack Repair site

And another site with operating instructions and maintenance tips.

http://www.norcoind.com/norco/download/instruc/BOTTLE%20JACK%20INST.pdf

Here is an animation of the inner workings of a hydraulic bottle jack.

http://www.hyjacks.net/animation.htm

[gmmills]

    I'am with Percy on the air bag system. The air bag acts as a shock absorber for the blade and at the same time keeping the blade tension correct. I feel this system adds significantly longer blade flex life. I"ve owned 2 Lt 40 mills with hyd tension and it does a great job at keeping the correct tension but, I feel it does little to help with shock absorbtion for the blade. If I were going to upgrade I would try to mount an air bag system.

[Tom]

If it's shock absorbing that one is after, why not put hydraulics behind a spring.  then you could measure the pressure from the hydraulic oil and still get some give from the spring.  It would be a lot easier, seems to me, than air.    ???

[JP]

You might take a look at  CHAMPIONSAWMILL. COM THEY USE A HYD. JACK FOR TENSION--MABY THEY WILL SELL YOU ONE? jp

[gmmills]

Tom,

     The hydraulic ram and spring combination is used on Timberking B20 mills. Seems to work well for them. Maybe the Timberking owners can give us more input.

[Fla._Deadheader]

We use air bags, 2 of 'em. Work very well. ;D ;D ;D ;D :D :D

[Radar67]

Anybody got any pictures of the air bag system?

The hydraulic tensioner seems to be the most user friendly, you can adjust it on the fly, it helps you know when the blade is heating up, just some of my thoughts so far.

[gmmills]

     Here's a couple of pic's of my air bag system on my LT70.


                                             


                                             
     
     These are the only two pics I have.  If you need more detailed pics let me know.