Bigblue&Goldie
Well-known member
I enjoy reading quick tool reviews, so I've been trying to remember to post them as I come across tools that I like. A recent purchase that has stuck out to me is the Blair Rotabroach hole cutters. In short, these are excellent tools that have changed how I do things.
I recently built a rolling stand for a JD2 hydraulic tubing bender which required drilling (2) 3/4" holes in 1/4" chromoly stock for mounting the main bender frame. I have a pretty good drill press, yet I wasn't looking forward to this procedure as drilling a hole of that size is better suited to much larger equipment than what I have at my disposal. After doing some reading I decided to break down and buy the Blair Rotabroach hole cutter set #11090 and a tube of their lubricant. The cost was ~$63 (going rate). Included in the kit are 5/16"-3/4" cutters, an arbor, 2 extra pilots, and a punch. Not cheap, but a bargain in the long run.
Manufacturer's Information:
https://www.blairequipment.com/rotabroach-cutters
Lube Stick:
https://shop.blairequipment.com/Cutter-Lubricant-p/11750.htm
1) The way these work is you use the center punch to locate your pilot in your material. This is a standard layout practice with a twist drill, so nothing unusual, Blair just makes it convenient by throwing one into the kit.
2) Thread on the appropriate size cutter to the arbor and align your material into your drill press. The pilot is spring loaded into the arbor, which make it super easy to make sure you have your stock perfectly lined up with your spindle (easier than lining up a twist drill).
3) Apply some Blair stick lube, which is really similar to a chapstick. I really liked this lube as it didn't make a mess and held up for the whole duration of the cuts.
CAUTION: if you are one of those dipshits that doesn't wear eye protection, these are not a tool for you.
4) Set your drill press/drill to the appropriate speed (speed table conveniently provided on lid of case) and feed her down.
Easy.
The Rotabroaches cut extremely smooth and you can be aggressive with your feed rate. These things remove some serious material, so expect a lot of stringy chips. Going back to my above caution, that pilot is spring loaded in order to also eject the slug that would ordinarily get jammed into the hole cutter......they come out like a bullet! I had one shoot across my garage 20' and hit the wall. They are no joke, wear your safety glasses!!! I was incredibly impressed with how fast and easy the Rotabroach made it through the chromoly. My 2 hole pattern was perfectly aligned due to how well the spring loaded pilot locates in the center punch *****.
Note how clean the holes are. I did zero post clean up. The bottom (not pictured) had a small burr, that was quickly buzzed off with a flap wheel or deburring tool.
Pros:
-All inclusive kit
-Cut very clean, nearly burr free hole
-No need to drill pilot hole
-Made in USA (except larger Holcutter sizes)
-Quality blow molded case
-Spare pilots included
-Fit 3/8" and 1/2" chucks
-Cut up to 1/2" thick stock (depending on size of Rotabroach)
-Cheaper than twist drills in equivalent sizes
-Cuts way cleaner and faster than a standard hole saw
-Kits don't overlap sizes
-Cuts thicker material than most step bits (also cuts faster)
-Work in hand drill or drill press
Cons:
-Initial buy in price (really not bad, but $63 is $63)
-Don't drill as deep as a twist drill
-Hard to remove cutters from arbor (requires 2 sets of pliers)
In summary, these are awesome tools for people that don't have access to a large drill press or mill, but need to make large, clean holes. I was so impressed that I bought their Holcutters/arbor to correlate with every size that I dimple die. I can't speak for longevity at this point, but I imagine it will be far better than a hole saw.
I recently built a rolling stand for a JD2 hydraulic tubing bender which required drilling (2) 3/4" holes in 1/4" chromoly stock for mounting the main bender frame. I have a pretty good drill press, yet I wasn't looking forward to this procedure as drilling a hole of that size is better suited to much larger equipment than what I have at my disposal. After doing some reading I decided to break down and buy the Blair Rotabroach hole cutter set #11090 and a tube of their lubricant. The cost was ~$63 (going rate). Included in the kit are 5/16"-3/4" cutters, an arbor, 2 extra pilots, and a punch. Not cheap, but a bargain in the long run.
Manufacturer's Information:
https://www.blairequipment.com/rotabroach-cutters
Lube Stick:
https://shop.blairequipment.com/Cutter-Lubricant-p/11750.htm
1) The way these work is you use the center punch to locate your pilot in your material. This is a standard layout practice with a twist drill, so nothing unusual, Blair just makes it convenient by throwing one into the kit.
2) Thread on the appropriate size cutter to the arbor and align your material into your drill press. The pilot is spring loaded into the arbor, which make it super easy to make sure you have your stock perfectly lined up with your spindle (easier than lining up a twist drill).
3) Apply some Blair stick lube, which is really similar to a chapstick. I really liked this lube as it didn't make a mess and held up for the whole duration of the cuts.
CAUTION: if you are one of those dipshits that doesn't wear eye protection, these are not a tool for you.
4) Set your drill press/drill to the appropriate speed (speed table conveniently provided on lid of case) and feed her down.
Easy.
The Rotabroaches cut extremely smooth and you can be aggressive with your feed rate. These things remove some serious material, so expect a lot of stringy chips. Going back to my above caution, that pilot is spring loaded in order to also eject the slug that would ordinarily get jammed into the hole cutter......they come out like a bullet! I had one shoot across my garage 20' and hit the wall. They are no joke, wear your safety glasses!!! I was incredibly impressed with how fast and easy the Rotabroach made it through the chromoly. My 2 hole pattern was perfectly aligned due to how well the spring loaded pilot locates in the center punch *****.
Note how clean the holes are. I did zero post clean up. The bottom (not pictured) had a small burr, that was quickly buzzed off with a flap wheel or deburring tool.
Pros:
-All inclusive kit
-Cut very clean, nearly burr free hole
-No need to drill pilot hole
-Made in USA (except larger Holcutter sizes)
-Quality blow molded case
-Spare pilots included
-Fit 3/8" and 1/2" chucks
-Cut up to 1/2" thick stock (depending on size of Rotabroach)
-Cheaper than twist drills in equivalent sizes
-Cuts way cleaner and faster than a standard hole saw
-Kits don't overlap sizes
-Cuts thicker material than most step bits (also cuts faster)
-Work in hand drill or drill press
Cons:
-Initial buy in price (really not bad, but $63 is $63)
-Don't drill as deep as a twist drill
-Hard to remove cutters from arbor (requires 2 sets of pliers)
In summary, these are awesome tools for people that don't have access to a large drill press or mill, but need to make large, clean holes. I was so impressed that I bought their Holcutters/arbor to correlate with every size that I dimple die. I can't speak for longevity at this point, but I imagine it will be far better than a hole saw.
Last edited:
out
- maybe, but don't hold yer breath 
