Vessel Impacta Question

[Mike S.]

So about a year ago I picked up the #2 and the #3 Impacta screwdrivers. I used the #2 for the first time a couple of months ago to remove the strikers for the rear hatch on one of my cars. It took several good hits, but it did the job and I was able to remove the screws without too much trouble.

More recently I got to use the #3 impact driver when I was replacing the rear rotors on my Acura. For some reason, I could not get the screws to budge. I must have struck all 4 screws (2 on each side) 50 times each with a 32 oz. ball peen dead blow hammer. I tried to grip the screwdriver as firmly as I could, and I could feel it compressing with some of the impacts. Puzzled, I pressed the tip of the screwdriver on the ground and pushed down on it. It compresses and springs back, but I couldn't see the tip actually rotating. I understand that it's only ~12° of rotation, so maybe I just didn't notice it?

I eventually gave up on the Impacta and started drilling out one of screws when I remembered that my dad had given me an old impact driver with the replaceable bits. I found a #3 Philips, or maybe it was JIS; either way it fit the head of the screw very securely. I swung the hammer back ready to start pounding away at the screw repeatedly, but I felt it break loose on the first strike. It was the same result for the 3 remaining screws.

I don't know if my #3 Impacta is defective, or if my dads old impact driver was just the better tool for the job?

 

[kb1982]

The old style definitely has some heft to them, but they work great.

 

[rlitman]

...I don't know if my #3 Impacta is defective, or if my dads old impact driver was just the better tool for the job?

The shaft of the Impacta acts like a torque-stick, limiting how much of the twisting impact makes it through. It strikes a near perfect balance with the #2, limiting the torque just enough to prevent the tip from shearing. I'm not sure that makes as much sense with the #3, though if the hole is in a recess, it might be the only good tool for the job.

The old school impact drivers don't have such long shafts that absorb the torque impact.

 

[Steve_P]

The shaft of the Impacta acts like a torque-stick, limiting how much of the twisting impact makes it through. It strikes a near perfect balance with the #2, limiting the torque just enough to prevent the tip from shearing. I'm not sure that makes as much sense with the #3, though if the hole is in a recess, it might be the only good tool for the job.

The old school impact drivers don't have such long shafts that absorb the torque impact.

This. The shaft is a long torsion rod. Neglecting material, torsional deflection is directly proportional to the length and diameter of the shaft. IMO, the impacta drivers are only for when a "proper' impact driver doesn't fit.

 

[pizza]

treat yourself to a new tool like a koken attack driver.

 

[Pexto]

This. The shaft is a long torsion rod. Neglecting material, torsional deflection is directly proportional to the length and diameter of the shaft. IMO, the impacta drivers are only for when a "proper' impact driver doesn't fit.

Minor correction - it's directly proportional to the length, but the stiffness varies as the fourth power of the shaft diameter.

Double the length, and the deflection doubles. Double the diameter, and the deflection will be 1/16 as much.

Like you, I don't view the Impacta as a real impact driver. But it's pretty quick and handy for stuff that's stuck just a little.

 

[Alienbaby17]

I bought the Impacta after reading numerous glowing reviews of it. The main thing I was intending to use it for was removing the “screws” that hold brake rotors in place. I have NEVER been successful with it for that purpose. Honestly, I was pretty disappointed. Perhaps that application isn’t what it’s ideally suited for but the reviews I had read made it seem like it would handle these without difficulty.

 

[steve855]

Minor correction - it's directly proportional to the length, but the stiffness varies as the fourth power of the shaft diameter.

Double the length, and the deflection doubles. Double the diameter, and the deflection will be 1/16 as much.

Like you, I don't view the Impacta as a real impact driver. But it's pretty quick and handy for stuff that's stuck just a little.

"Stuck just a little" is my experience too. I have the #2 Impacta, and also a true impact screwdriver (Craftsman) with short insert bits that I bought back in the 90s for motorcyle case cover screws. If the screw is actually stuck or really tight, impact wins.

 

[Odd-job]

Impactas are definitely lighter duty. Am on the hunt for a #1.

Have a bigger Craftsman/Lisle that takes 5/16 bits that I have adapted to take 1/4 bits. Definitely hits harder and twists more which is nice with expendable/replaceable bits.

After this the 3/8 Shake n break comes out along with penetrating oil and sometimes heat.

 

[JWC86]

They won’t replace an impact driver. They work better than a standard screw driver but they lose to much in the shaft to be very effective.

 

[BlitzcrankJapan]

Just like you would expect of a screwdriver, it is for light duty applications in materials such as wood.
The Vessel Impacta screw drivers work great around the house for old and stubborn screws such as in doors and their hinges.

A rusted in bolt with Phillips head such as on a car hub is too much for it and as you have found out will require a proper impact driver.
Vessel has a great made in Japan impact driver. Personally I have one made by Ko-Ken.