B21 Backhoe Thumb

[joea99]

My homemade hyd thumb on my backhoe attachment is only about as wide as the dipper stick, about 4". My homemade hyd thumb on my mini-X is much wider, about 10".

Why the diff? My wide thumb is often used to hold dirt in the bucket when digging. The reach of the mini-X is not great, and dirt can fall out w/o a thumb. The downside of this wider thumb is that you have to be careful not to twist it when grabbing something off-center. The B21 and my 2 units all use 25mm pins and can deliver some very powerful forces.

I grab a lot of heavy rocks and logs with my hoe, and often sandstone with shatter. I really wanted the narrow thumb to avoid damage to the thumb.

That is about all I do with the thumb is grab logs and rocks. No sandstone around here. Some shale but a lot of bluestone and what gets passed off as bluestone. I've not found the width to be a problem so far.

Might have to demolish some sheetmetal sheds in the spring. If and when the garage/shop ever gets built. On the agenda for that is to clear out some trees and move rocks. As you know it gets old using a manual thumb while digging and finding big rocks.

BTW, I found a reasonably priced cylinder that might work a Magister WTG 2x10. Not sure about this exact item, being uncertain about the needed stroke and length, but the ports are in the preferred orientation. The stroke is the main issue I guess. $1200 for a Kubota cylinder ain't gonna happen.

 

[dfkrug]

Open length, closed length, and stroke all important. Do a mockup to be sure. I have always modified the cyls to be optimal in all 3 criteria. Sometimes I just cut off and re-weld the cross-tube on the rod end.