(https://forestryforum.com/gallery/albums/userpics/45940/20170516_171128.jpg?easyrotate_cache=1494973008)
You would have 2 of these with a pnuematic cylinder inbetween. The center rod pieces stick up into the the slots in the plate that sandwitch the scissor mechanism. Seems it would be semi self adjusting as far as one could move further in than the other side. Of course it would still need the actual clamp pieces figured out But this was just a real rough idea. So to recap , two scissor mechanisms tied together by a spreading acutuator. (pnumatic cylinder or jack or etc etc) Any thoughts? The picture shows a top view then sideview of just one scissor. then at the bottom a top view of how cylinder fits inbetween.
LP, could be made to work but you have everything already to make it hydraulic and that would make it more controllable. The problem with air actuators on a mill is control they move fast slam in and out. You should have hyd. for a turner and feed, might as well use it to clamp also. Frank C.
Quote from: bandmiller2 on May 16, 2017, 08:58:05 PM
LP, could be made to work but you have everything already to make it hydraulic and that would make it more controllable. The problem with air actuators on a mill is control they move fast slam in and out. You should have hyd. for a turner and feed, might as well use it to clamp also. Frank C.
x2 on the hydraulic vs pneumatic.
In this case I think hydraulic would overpower the linkage. Air would provide a built in buffer. You could put a rate limiter in on the air.
Not sure what you are clamping, logs or? My woodmizer is set for air log handeling and clamping. Most of the cylinders use leverage to increase power. I could get you some pictures if you could explain what you are trying to accomplish. The only advantge I can see to air is that the leaks don't require cleanup.
Quote from: lowpull on May 16, 2017, 09:25:59 PM
In this case I think hydraulic would overpower the linkage. Air would provide a built in buffer. You could put a rate limiter in on the air.
i dont think he could slow down the air cyl and the dog still hold at least if he is sawing logs if sawing cants it might work ??? the air cyl depends on the speed to set the dog as it doesnt have the strength of hyd to push the dog into the log so it has to hit it pretty hard to get a good bite :)
assuming you have a bandmill from the drawing ???
low pull your sciccor linkage looks fine but there is easier way that would likely have a longer life :) you can put a pivoting dog directly on the cyl end that is about 4" long that sticks up all time and when the log rolls over it the dog will lay down at then flip back up when the log passes the dog when you hit the button the dog will pull in and hold the log and you dont have any linkage to maintain just the cyl ;) the only problem with air dogs is it takes enough air that it makes it hard to stay portable :-\ i have 2 hyd mills and would love to go to air but i have to stay portable for now at least the hyd works good but is just to slow for me :) i can make a drawing if you want provided one of the girls can figure out how post it for me ::) im better at the mill or in the woods thn at the keyboard :-\ :D :D :D
I like the concept. Great idea. I was actually just thinking about something very similar on my drive home from work yesterday.
Instead of double stacking the framing with the spacer you could single stack it and use ring around the board clamps bar. This will give you the structure and slide nicely. It would effectively make half the work to fabricate.
LP, we are at a disadvantage here as we don't even know what you have for a mill. Its your mill go ahead and build your air dogging, if your not happy you can convert to hydraulic. It will work its just how well that is the question. Frank C.
Right now I am making the drawings and materials list to make my bandsaw mill. I plan on welding all my attachments onto the side pieces before I ever weld in the cross pieces. And cross pieces will have everything welded on before they are welded in. Now I am trying to figure out what attachment points I need to cut out on the plasma table to be welded on now for future improvements. The scissor clamp idea just popped into my head to A. be able to cut out easy on the plasma table and B. get two self adjusting clamps for one cylinder. I am trying to steal the best Ideas off of this site to incorporate into my build. I start bringing steel home in a little over a week.
Thanks LP, now we know where your going. Be sure to incorporate a log turner ether two plane or Piney woods you will pat yourself on the back each time you turn a big-in. Frank C.
Put a flow control valve in the return stroke.
This is similar to an idea I have, I am slowly getting things to do hydraulics, but that will be a while (have to build the mill first).
I have easy access to air, pretty much anywhere I need it, and I understand and work with air a LOT better than I do with hydraulics. I was at a garage sale last week and picked up a 1/2" air impact gun dirt cheap. I have this wild idea of clamping the gun where needed, put a actuator on the forward/reverse or use a solenoid, then I can just run a airline to the gun and control it with a on/off valve wherever. This would let me run, say..a healthy chunk of allthread with a clamp attached. Just one of my wild ideas I get while driving back and forth for a couple hours at a time. Not sure if this helps, or confuses, but its a thought.
My wild idea lastnight consisted of everything being all thread with 3/4" nuts welded to the end. That way I can use either my 1/4" M18 impact driver or my 1/2"
No need for hydraulics with good battery tools.
Quote from: Crusarius on May 18, 2017, 04:10:50 PM
My wild idea lastnight consisted of everything being all thread with 3/4" nuts welded to the end. That way I can use either my 1/4" M18 impact driver or my 1/2"
No need for hydraulics with good battery tools.
Better to go with acme thread... It will last much longer.
but isn't it alot more expensive?
Quote from: Crusarius on May 18, 2017, 06:07:15 PM
but isn't it alot more expensive?
Not bad on E-bay...