The Forestry Forum

Hi guys.

Well, if i was to make a grapple skidder arm.

A bit like this one.

(https://forestryforum.com/gallery/albums/userpics/19153/8208516.jpg?easyrotate_cache=1529587319)

A big vertical fairlead with a log basket. With the arm on top. How would you go about making the pivot point?

I have many pillow blocks. Two huge ones, that i would rather keep for the back blade. And two, for a one inch shaft i think.  Would those be suficient? Or should i use babett bearings? Or, steel against steel with grease?

What's your take?

Thanks.

I double checked. I have 32mm pillow blocks, and 38mm ones. Thats 1 1/4 and 1 1/2. 

I would not count on a cast pillow block component at all in that application.  If pillow blocks were up to the task every excavator would have several in the stick but they dont.  Theyre all welded, bushed and reamed to fit. 

I would use 1.5 to 2" steel shaft for pins and come up with a replaceable bushing inside a steel housing of some sort.  The bushing doesnt have to be fancy, it just has to be softer than the piece you dont want worn out. i have made pins from mild steel, chromoly, stainless, 4140, titanium and so forth.  I have made bushings from bronze, sched 40 pipe, brass, aluminum, copper pipe.. It all depends on load, and frequency of using that pivot point. For brute strength stuff steel and oil impregnated bronze seem to be the standard.

Sometimes i make a pivot out of steel on steel and say i will decide on the bushing after i see the wear pattern on version 1.  In this case i will start with a smaller pin, say 1" or so and leave plenty of room for reaming up a size and welding on a collar or pin locking tab, etc etc

Thanks a lot Mike. Well, i already have the stuff for the arm. I think. A chairlift frame. I have a few chairlift bogie pins. One is about 2 good inches. May be 2 ft long. 

I gonna hunt for brass.