Review: Griot's Garage Boss 21 Long Throw Polisher - Comparison To Rupes 21ES

[Marc08EX]

Best review I've ever seen. Seriously.

Thanks a lot for the compliments, Mark!!! Just trying to help.

However, ALL of the 21mm polishers struggle with concave surfaces. With that said, I think I'm going to try the BOSS 15 instead of the 21. May not have quite the cutting power(still good), but more versatile.

Well it really depends on how concave the surface is. If the surface has a very loose radius then you just make the pad follow the curvature of the surface. If it's a tight radius like the ones I have in the video then there's nothing you can do. But some 3401 owners would argue that the Flex will continue to spin in situations like this. Yeah the 3401 is spinning but are you really correcting? I'm sure the 6.5" pad isn't making full contact with the surface. So this is a flawed argument.

When the user encounters any surface that makes the spinning stop, you just have to adjust your technique to keep the pad spinning. And if the surface has an concave surface with a tight radius then maybe it's best to use a 3" polisher.

I do agree with you that the 15mm throw will deal with curves better than the 21. The shorter throw combined with the smaller pad will make it spin more freely on tight radius curves.

Great review!

Did you measure the current draw? One more can be more efficient than another yet deliver the same results.

Thanks a lot, Bunky! No I didn't measure current draw. I don't have any equipment to do so.

Awesome review Marc!!!!!!
Very detailed and I know a lot of time and thought went into it, which I can appreciate deeply!

Keep up the great work!

Thanks you.

Thank you so much for the kind words, Tim!!! Hope you're doing well.

[ski2]

[QUOTE=Marc08EX;1274675]
When the user encounters any surface that makes the spinning stop, you just have to adjust your technique to keep the pad spinning. And if the surface has an concave surface with a tight radius then maybe it's best to use a 3" polisher.

I do agree with you that the 15mm throw will deal with curves better than the 21. The shorter throw combined with the smaller pad will make it spin more freely on tight radius curves.QUOTE]

When polishing with my G15 on speed 5 it seemed second nature to bump it up to speed 6 when I encountered small radius curves but it was no better on speed 6. However, I seemed to get better rotation leaving it on speed 5 and adding a little pressure. It's like the G15 went into overdrive.

[Loach]

Thank you for this great review and comparison!

[davey g-force]

Yeah the 3401 is spinning but are you really correcting? I'm sure the 6.5" pad isn't making full contact with the surface. So this is a flawed argument

Fair point Marc, but can't you get a smaller BP / pad for the Flex?

[Djmagnum]

Gentleman, I would like to challenge the power ratings on the griots garage 21 boss. This is just my 2 cents, but both machines weigh 6.2 pounds correct?

The materials used are almost identical, plastic housing, rubber cord, gear head etc.

If the griots garage claims they have 40% more power, where is the extra weight from the motor? You need an increase of iron in the stator, and bigger magnets. Which we all know isn't light, and the motor would have to weigh closer to 40% more to have that figure be accurate.

I'm not sure if I can post links from other pages on here, but here is some information I found:

To speak to the "wattage" of a motor is a misnomer...
The wattage is USALLY set by the controller that runs the motor..
(i.e. This is no difference between a 500w and a 1000w "motor", it's the controller that provides more power (amps) and is the controlling factor..) the more power you feed, the more heat builds up.

And also I noticed in the 2 YouTube videos that compared the griots vs the Rupes on the 15 pound weight test (load test) the griots slowed down, while the Rupes didn't slow its rotation.

Also, when you start the griots it doesn't have the "smart start" the Rupes has. Doing research, this is called a DOL controller. The most basic controller for motors.

The Rupes however has a reduced voltage starter, softer starts.
It also has an intelligent controller, meaning it adjust the input current to the load. Ie when you push down on the pad (increasing the load) it puts in more current (power) to maintain the speed of the polisher. And also when you lighten up on the pad, it doesn't spin faster and faster (because of less load) it maintains the same speed, reduces voltage which in turn reduces motor heat, run under light load for a large part of the time, resulting In also less noise, and vibrations generated by the motor.

I'm not sure about this, but when seeing mechanical resistance graphs correlated to the load, (in this case pressure on the pad, weight) motors show up to 1.5 to 3 times the average current needed to operate at the same rpms due to the heavier load the motor is operating under. Again I'm not sure, but if Rupes can maintain its speed on level 5 or 6, and the griots bogs down, which is really more powerful?

Power specs aren't really helpful, it's all about the type of controller used that feeds the motor. And seeing there is no weight difference in the 2, I would say if the griots did indeed have a bigger motor, it would heat up faster, resulting in insulation damage of the motor faster, since it also doesn't have smart controllers and just basic made in China DOLs, it cannot keep that power under heavier loads like the Rupes can, and would waste power on lighter loads and have more heat.

This is a lot to take in, but after some research I would definitely take the Rupes over the boss 21. Especially if they are the same price, Italian craftsmanship made by hand it's a no brainier.

Thoughts?

[RaskyR1]

Gentleman, I would like to challenge the power ratings on the griots garage 21 boss. This is just my 2 cents, but both machines weigh 6.2 pounds correct?

The materials used are almost identical, plastic housing, rubber cord, gear head etc.

If the griots garage claims they have 40% more power, where is the extra weight from the motor? You need an increase of iron in the stator, and bigger magnets. Which we all know isn't light, and the motor would have to weigh closer to 40% more to have that figure be accurate.

I'm not sure if I can post links from other pages on here, but here is some information I found:

To speak to the "wattage" of a motor is a misnomer...
The wattage is USALLY set by the controller that runs the motor..
(i.e. This is no difference between a 500w and a 1000w "motor", it's the controller that provides more power (amps) and is the controlling factor..) the more power you feed, the more heat builds up.

And also I noticed in the 2 YouTube videos that compared the griots vs the Rupes on the 15 pound weight test (load test) the griots slowed down, while the Rupes didn't slow its rotation.

Also, when you start the griots it doesn't have the "smart start" the Rupes has. Doing research, this is called a DOL controller. The most basic controller for motors.

The Rupes however has a reduced voltage starter, softer starts.
It also has an intelligent controller, meaning it adjust the input current to the load. Ie when you push down on the pad (increasing the load) it puts in more current (power) to maintain the speed of the polisher. And also when you lighten up on the pad, it doesn't spin faster and faster (because of less load) it maintains the same speed, reduces voltage which in turn reduces motor heat, run under light load for a large part of the time, resulting In also less noise, and vibrations generated by the motor.

I'm not sure about this, but when seeing mechanical resistance graphs correlated to the load, (in this case pressure on the pad, weight) motors show up to 1.5 to 3 times the average current needed to operate at the same rpms due to the heavier load the motor is operating under. Again I'm not sure, but if Rupes can maintain its speed on level 5 or 6, and the griots bogs down, which is really more powerful?

Power specs aren't really helpful, it's all about the type of controller used that feeds the motor. And seeing there is no weight difference in the 2, I would say if the griots did indeed have a bigger motor, it would heat up faster, resulting in insulation damage of the motor faster, since it also doesn't have smart controllers and just basic made in China DOLs, it cannot keep that power under heavier loads like the Rupes can, and would waste power on lighter loads and have more heat.

This is a lot to take in, but after some research I would definitely take the Rupes over the boss 21. Especially if they are the same price, Italian craftsmanship made by hand it's a no brainier.

Thoughts?

I'm not an electrical engineer so I can't comment on any of that. I can say that anyone I've talked too or that has posted who's used both machine side by side will tell you the BOSS has a little more power, simple as that. The head does get warmer than the Rupes, but never uncomfortable and it's still cooler than tools like the Flex run.

Here's a thermal of the BOSS after 36hrs straight on speed 6.



Here is the Rupes motor next to the BOSS

[Djmagnum]

I'm not an electrical engineer so I can't comment on any of that. I can say that anyone I've talked too or that has posted who's used both machine side by side will tell you the BOSS has a little more power, simple as that. The head does get warmer than the Rupes, but never uncomfortable and it's still cooler than tools like the Flex run.

Here's a thermal of the BOSS after 36hrs straight on speed 6.



Here is the Rupes motor next to the BOSS

Thank you for that image. And the flex, is it worth it to have if you have a rotary and rupes already?

[RaskyR1]

Thank you for that image. And the flex, is it worth it to have if you have a rotary and rupes already?

Now that will depend on who you ask!

[Djmagnum]

Very true ^

Rupes first, then flex because I have a detailing problem.

[Bunky]

G
To speak to the "wattage" of a motor is a misnomer...
The wattage is USALLY set by the controller that runs the motor..
(i.e. This is no difference between a 500w and a 1000w "motor", it's the controller that provides more power (amps) and is the controlling factor..) the more power you feed, the more heat builds up.

I think your point is the same motor can be rated at two different wattages only due to how they drive it. All things being equal the high wattage version would like fail sooner due to the heat.