Air or Hydraulic?

[countrysaw]

ok guys i need some input

I am making a somewhat automatic circle mill when i get home, and have had some questions about the carraige, first of them being what is better air or hydraulic carraiges?  ???

I have never had the experience to work around a automatic mill, other than bandmills, but have spent some time operating a handset frick.  I have a fair amount of knowledge with fluid power trains (hyd.) and have no working knowledge of pneumatics other than air tools. :(

I was just thinking that hyd. would be more consitent and powerful than air, and i have heard about problems with moisture, seal problems and cold with air systems.  My roommate (working on mechanichal eng. degree 8)) also agrees with this, but most of the time you hear about air carraiges and occasionaly hyd., and i wondered if some of you can list the benifits of air.

also, we have been wondering about using hyd. rams to advance the knees, using the programs that you control a robotic welder with, but i was thinking that those welders operate under a consistent load, and the knees would work under a varying load, such as the weight of logs.  so should i just stick with a handset style driven by hyd.  ???? 

well sorry for being so long winded, i have more questions, but i do not want to wear you guys out, and i have plenty of time to work on the design before the miller even gets hot :-[

[tnlogger]

 countrysaw if you want to go auto check out sawmillexchange.com
the price of all circle mills is down the tubes right now so it's a buyers market
When i get home i'll send you a few links to surf  . what am i saying you are surfing ( in the sand) :D

[twostroke_blood]

Countrysaw, Im saposing "get Home" means your in Iraq ? I cant answer your question, but I'd like to thank you for your service. Semper fi from an old 0331 60 gunner.

[DragonsBane]

countrysaw,

If you have knowledge of hydraulics then stick with that. IMHO hydraulics are bettre than hydraulics for more reasons than I can list here. The biggest problem is the initial cost. Good luck in whatever you decide to do. I'm working on a somewhat automated swing blade powered by hydraulics myself right now. I hope to get some pics up soon.

Later all.....

[thedeeredude]

First off, thanks for what you and your buddies are doing in the War on Terror.  Second off, I often thought about using a handset mill with a hydraulic or pneumatic dealy to advance and retract the knees.  Something like a cylinder mounted at the setworks so you just push a button and it advances it.  But I just like the idea cuz I don't have to think as hard initially 8)   

[countrysaw]

hi everyone, thanks for your support of all of us over here, we all appreciate it, and thank you to all of the vets and everyone else at home who supports us and makes the US keep on going.

tnlogger- thanks for the link, some good stuff in there i had not discovered that site yet.

DB, good luck with the swingblade, it will be kinda tricky, but with enough enginuity anything is a can do.

deere dude, i am thinking about cutting out manual setworks alltogether, and using a hyd. cylinder on each knee, actually thinking about iti have 4 matching cylinders sitting in the shop that came off of 4400 turbo combines (head lift cyl.) i dont know if the stroke on them will be long enough but we will see.  the scematic that we thought up for the control of the cylinders is a closed center electronic valve on the carraige with equal lengths of line runnig to each cyl. and the valve would be controlled by my laptop with software for programming electronic-hyd. welders, although this plan is still in the brainstorm phase.  i was thinking that i could set up the sofware to advance the log to preset distances, such as 4/4 6/4 8/4 etc., just so all i would have to do every time i bring the carraige back for the next cut would be press enter and run the carraige by again, not really having to mess with setworks.

zach

[stumpy]

I also can't answer your question, but I wanted to thank you as well. It's too bad there are many people (especialy the media) who don't appreciate what you all are doing for us and the rest of the world. The majority of people do however and we will never be able to repay you all. I hope you and all the other fine soldiers come home safe.

[gary]

Sorry I can't help . Just wanted to say thanks  for what your doing.

[DragonsBane]

forgot to thank you guys for what your doing over there. been there done that. anyway stay safe and keep your head down. and most of all when in doubt shoot to kill.  if you have any doubts about me read then bottom of my sig.

later all......

[Ron Wenrich]

Hydraulic is the best way to go.  Just the noise factor on the air would be enough of a factor for me.   Air is quicker than hydraulics, but you can feather the hydraulics beter than you can air. 

The automatics are pretty good if you want production.  The cylinders that you are talking aboutare already being used on carriages that have linear positioners.  Farily high tech and are always associated with a computer setworks.  It wouldn't be my choice for a setworks.

Most run with a chains to advance the knees.  They run from a common shaft so each knee will advance the same amount.  Very important.  With the cylinders, you would have to get the same amount of oil to each cylinder so they advance evenly.  That means more oil to be carried by the pantograph.  I have seen some carriages that have a hydraulic system on the carriage.  The cylinders would make for an awful wide carriage. 

As stated, circle mills are pretty cheap.  You can have an automatic for less money than you can build one.  No need to reinvent the wheel.  Use the extra money to buy logs and the extra time to go fishing.  Troubleshooting new equipment takes a lot of time.

[karl]

Don't have a clue- just want to say THANKS!

Keep you chin up and your head down.

May you all be home safe and soon.

You are appreciated.

[Sawyerfortyish]

My first 18 years I spent on a manuel mill so when I got a Frick mill with a air over electric carrige I thought I had died and went to heaven. Don't know exactly how each thing does what it does but push a button things move.If it leaks someplace I take it apart and fix it then I know how it works. Never seen an all hydraulic mill so I can't compare them. But if I have learned anything it's that if you want something buy it so you can get right to work. Like Ron said don't spend your time reinventing something. Allready to use and working mills can be bought for less than what your time is worth to try and make one. Just went to an auction the HMC mill complete with live deck log turner lazer lights saw cab with a lot of bells and whisels sold for 5G How could you go wrong?

[Sawyerfortyish]

In my rambling on about mills I forgot to say thanks for Defending the rights and freedoms we all sometimes take for granted.

[countrysaw]

hi guys, i understand what you said about reinventing the wheel, i guess i just have a hard time buying something that i have a lot of the stuff to build it already, and loading up the semi to go pick it up.  and where i am from all i have ever seen for sale are old handset mills.

this plan has been in the back of my mind ever since i was working with an old frick, and having been working on farm equipment for work and cutting up scrap when there was not any work,  and well you know how some people are, when i saw something i could use it got thrown in the bed of the truck instead of on the gooseneck.

i have been looking at other automatic mills online, and the prices are decent, but i was just thinking that i could build something that was specific to my needs, when i am home on leave i will have to go looking for some automatic mills.

and ron, i have been thinking about what you said about the width of the carraige, i looked at the rough BP's and i realized that rams would make the carraige too wide, this making it heavier and using more steel to make it, and using up more power to move it.  so i was thinking that chains and a common shaft would really make things easier. 

one last thought, i made two log turners that are made out of gathering chains off of combines and hyd. motors off of conveyor belts from an old quarry, and they are raised by 10" stroke 2 1/2" bore cyl., i was just wondring if anyone out there would think that there would be any weak points in these and if the chains will hold up.

zach

   

[Sawyerfortyish]

Zach I have a chain type log turner and I can't think of any chain on a combine that would hold up for the logs I saw. The only chain that I will say could work to build a turner would be off of a trencher. The chain on a log turner has to be hardened and strong to be able to pick up on a log with one tooth that sometimes can weigh a ton or more. Picking up on a log that big with one small part of a chain can put a lot of stress all in one area and if it isn't strong it will break. Just another thought maybe you could use two of them cylinders to make a bar type turner instead of a chain turner.

[countrysaw]

yes sawyerfortyish, i think that the combine chains also may be a little weak, so when i get home i will have to go back to the boneyard and find an old trencher, and those combine chain turners will get the hyd. rams taken off and go back on the forks of the tractor. ???