The "thumb"
- Thread starter WinterDeere
- Start date
Gordon Gould
Super Member
- Joined
- Apr 1, 2007
- Messages
- 6,235
- Location
- NorthEastern, VT
- Tractor
- Kubota L3010DT, Kubota M5640SUD, Dresser TD7G Dozer
In my mind if you need to load logs with any degree of fine control you will want something short. Working with forks DOWN IN a trailer or out 3 or 4 feet from your point of rotation is not easy. I realize you already have the forks but this may be a bigger trade-off than you think.
Just my two cents.
gg
Just my two cents.
gg
Smokeydog
Elite Member
Sage advise.
Sawyer Rob
Super Member
In my mind, one of the advantages of pallet forks for working logs is that they are longer.
I don't consider myself some kind of a super operator, and I don't have any problem at all with the forks being long, as long as the grapple matches the forks that's the important part!
I can dig the log out I want of the bottom of a pile of logs and all kinds of other things that use the advantage of longer forks.
Plus, the longer forks make the tool useful for many other operations like moving boxes of firewood or picking up piles of brush or picking up multiples of logs and letting them roll off into place one by one.
These are things I do all the time working with firewood and saw logs.
SR
I don't consider myself some kind of a super operator, and I don't have any problem at all with the forks being long, as long as the grapple matches the forks that's the important part!
I can dig the log out I want of the bottom of a pile of logs and all kinds of other things that use the advantage of longer forks.
Plus, the longer forks make the tool useful for many other operations like moving boxes of firewood or picking up piles of brush or picking up multiples of logs and letting them roll off into place one by one.
These are things I do all the time working with firewood and saw logs.
SR
OP
WinterDeere
Elite Member
First, on grease fittings, bushings, etc. Nothing is decided yet, as I see both sides of the argument. This is a homeowner (non-commercial) application, so wear will be limited by hours, and I don't think "in short order" is really applicable here. But, if I'm going to build it, I'd like it to last a good 20 years and be sellable when I'm done with it, so this is not a point I'm completely ignoring, either.
I will aim to use bushings drilled for zerks if possible, but even if not, simply pulling the pin out and greasing it before any long weekend of use might also be acceptable, in this application.
This project may have to go on hold for awhile, I just got notification that some new work is coming in that will have me working a lot of overtime the next few months. But as I continue to toy with the idea in my spare time, I'll be doing it with a mind toward making this thumb work on both the current forks (52") and potential future shorter forks.
edit: SR's last post came in simultaneously to this, while I was typing. Good advice to consider!
I will aim to use bushings drilled for zerks if possible, but even if not, simply pulling the pin out and greasing it before any long weekend of use might also be acceptable, in this application.
My thoughts exactly. In fact I think I mentioned this earlier, although the thread has gotten so long I won't go hunting for it. I'm thinking I might make a spare set of short forks to slide onto this frame, for this purpose. This will let me optimize them for holding logs, if that ends up being their only purpose, such as adding some curvature to the lower "short forks".
This project may have to go on hold for awhile, I just got notification that some new work is coming in that will have me working a lot of overtime the next few months. But as I continue to toy with the idea in my spare time, I'll be doing it with a mind toward making this thumb work on both the current forks (52") and potential future shorter forks.
edit: SR's last post came in simultaneously to this, while I was typing. Good advice to consider!
OP
WinterDeere
Elite Member
One thing that bothers me with my design posted above is the short distance between the thumb pivot and where the my piston attaches to the top link of the 3-point pins already present on the fork set. The effect is that the ~7000 lb. exerted from the piston translates to very low force out at the end of the thumb.
But I see now that your thumb pivot appears to be very close to the point where the piston attaches to the back of the thumb. Is that section of square tubing to which the thumb attaches fixed solid, or does it also pivot down at the fork frame?
I drew an arrow to the piece I'm talking about, in your photo:
ptsg
Super Member
I'll share some pictures of similar style of thumb and forks setup we have here for brainstorming purposes.
When I'm doing DIY projects, I usually look at lots of pictures and absorb as much as possible.
When I'm doing DIY projects, I usually look at lots of pictures and absorb as much as possible.
Sawyer Rob
Super Member
It's solid and it has amazing amount of clamping force, obviously it has a very good cylinder on it.
BTW, it's not square tubing, it's heavy channel iron and super strong.
SR
BTW, it's not square tubing, it's heavy channel iron and super strong.
SR
OP
WinterDeere
Elite Member
Thanks, @ptsg and Rob! Those photos are super helpful @ptsg, as I never even considered mounting the cylinder that way. I will definitely play with that idea.
Thanks for the info on your setup too, @Sawyer Rob. It looks like a I have some time to play with ideas, a new project that came in is going to keep me away from doing much personal fab work the next few weeks.
Thanks for the info on your setup too, @Sawyer Rob. It looks like a I have some time to play with ideas, a new project that came in is going to keep me away from doing much personal fab work the next few weeks.