How to Measure your Excavator for a Thumb Attachment February 17 2016, 29 Comments
Measuring Instructions for Thumb Attachment
At www.MiniExcavatorThumbs.com the most common question we get asked is, what size thumb do I need for my machine?
Operating weight is a great indicator but for those who aren't certain our advice is; "If your purchasing a thumb attachment for an excavator or backhoe the smartest thing to do is to measure the machine to get the exact length thumb your machine requires." It's a simple process and only takes five minutes to ensure you get the best fit.
Before Measuring Consider this
Weld on or Pin on - Before measuring your machine you should consider the style thumb attachment your looking for. The Digram above is for a Weld on Mounting Excavator Thumb. If your looking for a Pin on Style the instruction will change. Keep in mind if you choose the pin on style you'll need to take off the thumb each time you swap the bucket out.
Length of Arm - Another thing to take into consideration is the length of your arm . Sometimes machines of certain types can have shorter than normal arms. This can impact the required size for Hydraulic Thumb attachments due to the cylinder and two mounting brackets. If this is the case a shorter length thumb may be a better fit.
Quick Attach - If you have a quick attach (quick coupler) that allows you to easily swap out your buckets on your excavator this can extend your bucket out further and a longer thumb will work better than what the operating weight of the machine calls for.
Now that you've given it some thought the measuring process is very simple. It's as easy as 1.2.3. Reference the diagrams provided for help, note the digram1. below is for the Weld On Excavator Thumb and the diagram2. is for the Pin On Excavator Thumb.
Three Steps ( Weld on Style Mounting)
Step 1. Position Arm - You'll want the Arm ( Or "Boom" or "Sitck or Whatever other name you call it) of your machine to be Straight up and down. Vertical with the ground.
Step 2. Position Bucket - Your machines bucket should then be positioned at a 90 degree angel with the arm. Parallel with the ground to form an "L" Shape with the Arm of the machine.
Step 3. Measure - Standing in front of the bucket ( between the machine and the arm) measure from the flat front of the arm right above the top of the bucket, across the bucket to the edge of the teeth.
Pin On Style - Pin on thumbs require 3 different measurements. Standing on the Side of the bucket you want to measure from the center of the pin ( the pin that attaches the bucket to the arm )to the teeth on the edge of the bucket. You'll also want to measure the outside width of the Dog Ears ( On the bucket ) and finally you'll need the diameter of the pin.
Better Safe than sorry
This is exactly how long the excavator thumb should be at least. If in doubt its better to get something longer than necessary. You do not want to get something shorter this could cause the bucket and thumb to bind up or debris will get caught in between the to attachments and bind up. Better safe than sorry.
When purchasing any attachment its always best to take the time to get the exact measurements. It's like the old saying goes measure twice cut once. In this case measure twice purchase once and get exactly what you need haha.
Once you know what size thumb you need give us a shout and we'll get you the perfect excavator thumb for your machine in no time.