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View Full Version : Grizzly Magnetic Motor Brake - Questions.



Allan Speers
05-21-2015, 12:16 AM
A few questions for anyone who happens to have a Grizzly machine (especially a band saw) with their magnetic motor brake:

I am about to pick up a used G0531B band saw. It's the later version with the magnetic brake. (Early ones have a mechanical brake) I am VERY concerned about how well this brake works. (or doesn't)

note: This is a huge, HUGE deal for me, since I don't want a saw without a good & fast brake. Had I bought a vintage saw, I was planning on installing a 3-ph motor plus a VFD with extra braking resistors. That setup will completely stop a motor in just a few seconds.
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Until about an hour ago, I thought this brake used an electro-magnet. However, as I was analyzing the electronics, so as to add a foot-operated E-stop switch, I see no power going to the brake.


### Is this true? Is it purely mechanical? If so, then -


JUST HOW FAST DOES THE BLADE STOP, once you hit the off-button?

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I don't even see any centrifigul contraption, so is the magnetic is always active, meaning the motor is always fighting it? Can this possibly be?

Did Grizzly switch to the magnetic brake because it’s superior to a mechanical one, or because it’s cheaper? I suspect the latter, as it appears to be a LOT cheaper.

I see now that their new top-end saws have a "Lightning fast electronic brake," and the motors on these have an extra (fourth) wire going into them. This sounds like an improvement, so I guess mine isn't "lightning fast," hence this query.

Erik Loza
05-21-2015, 12:24 AM
...and the motors on these have an extra (fourth) wire going into them...

That could imply DC injection braking but the manufacturer would need to answer that.

Did you create that whole complaining thread about a used machine you don't even own yet?

Erik

Allan Speers
05-21-2015, 12:29 AM
Did you create that whole complaining thread about a used machine you don't even own yet?


I'm complaining about tech support for the machine I don't have here yet, if that's what you mean.
Funny, you write "the manufacturer would need to answer that." and then knock me for complaining that the manufacturer wouldn't give me any information.

Once that beast is here, I'm stuck with it. I can't add a mechanical brake to it, and I can't afford to buy a 5 HP 3-ph motor and VFD for it. - This stuff is IMPORTANT.
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"DC injection braking" - yes that's quite possible. I'm reading up on that now, thanks. (Sadly, it applies to the wrong saw, but it's good info to have.)

Ken Fitzgerald
05-21-2015, 1:04 AM
Allen,

If you would take the time to look at the schematic that you provided you will see that a DC voltage is applied to the magnetic brake. Now if you take the time to look at the parts list and drawing you will find that the magnetic brake breaks down into parts including a brake shoe. This tool has a electro-mechanical brake. I would guess, the applied DC voltage pulls the brake shoe away from the disk.

If you look at the manual you will find that brake requires a mechanical adjustment if the blade takes longer than 5 seconds to stop.

All this information without calling anybody names or ranting to anybody.

Allan Speers
05-21-2015, 1:09 AM
Allen,

If you would take the time to look at the schematic that you provided you will see that a DC voltage is applied to the magnetic brake.

I don't know HOW to see that from the schematic. I'm not educated enough in electronics.

Luckily, you are, so thanks !

5 seconds doesn't sound too bad at all.

Rick Fisher
05-21-2015, 1:49 AM
I have a Jointer with an electromagnetic brake, it works when the power is off. I think that's pretty common ... When I hit the power button, it stops the Jointer pretty darn fast.. maybe 3 -4 seconds ?

In order to turn the cutterhead free hand, the power needs to be turned on ..

Matt Day
05-21-2015, 8:53 AM
Erik, could you just give him a MM so we can be spared from all these threads?

Myk Rian
05-21-2015, 8:54 AM
I don't know HOW to see that from the schematic. I'm not educated enough in electronics.

Luckily, you are, so thanks !

5 seconds doesn't sound too bad at all.
Do you often throw a hissie fit over things you know nothing about? I feel sorry for the guy at Grizzly.

john lawson
05-21-2015, 9:13 AM
Allen,

If you would take the time to look at the schematic that you provided you will see that a DC voltage is applied to the magnetic brake. Now if you take the time to look at the parts list and drawing you will find that the magnetic brake breaks down into parts including a brake shoe. This tool has a electro-mechanical brake. I would guess, the applied DC voltage pulls the brake shoe away from the disk.

If you look at the manual you will find that brake requires a mechanical adjustment if the blade takes longer than 5 seconds to stop.

All this information without calling anybody names or ranting to anybody.

Yeah, what do you think this is, a place where you can come on and ask questions and get help for things you don't understand? What were you thinking?

Erik Loza
05-21-2015, 10:27 AM
Erik, could you just give him a MM so we can be spared from all these threads?

LOL, Matt....


I have a Jointer with an electromagnetic brake, it works when the power is off. I think that's pretty common ... When I hit the power button, it stops the Jointer pretty darn fast.. maybe 3 -4 seconds?

This is a very good point ^^^.... Not trying to be cute by saying this but it's a hobby-level (as are the MM16/MM20/MM24...) vertical bandsaw we're talking about, not a shaper with a 5lb tool spinning at 5,000rpm or a table saw with a 16" blade. If you have a decent mechanical footbrake that has an interlock switch, do you really need an electric or magnetic motor brake? It's a bandsaw, a machine with three moving parts. Speaking only for myself, in 11+ years of using bandsaws of this level, I cannot recall a time where I needed to be able to stop the machine "better" (however one might define that). How complicated does it need to be in order to do its job? Do you really need to turn a Honda Civic into the space shuttle to resaw some wood? On the list of things you could ask for on a bandsaw that would make it cut better, there is lots of other stuff that would come to mind before this. Just my 2-cents as always.

Erik

Peter Aeschliman
05-21-2015, 10:30 AM
Do you often throw a hissie fit over things you know nothing about? I feel sorry for the guy at Grizzly.

Agreed. Pretty lame, I must say.

David Kumm
05-21-2015, 11:10 AM
I have all types of brakes on my machines and electro mechanical are the least favorite. Mine are a pain to adjust and lots to go wrong. Depends on how easy the access is. DC injection are great for direct drive machines like jointers and planers but not so much for shapers and table saws because the weight of the head changes. Injection brakes also need to be sized properly if you do multiple starts and stops in an hour and many are undersized for non production use. For bandsaws I really prefer a foot brake with a good pad as I'd much rather spend extra for more saw and less brake. Dave

John Lanciani
05-21-2015, 11:24 AM
LOL, Matt....



This is a very good point ^^^.... Not trying to be cute by saying this but it's a hobby-level (as are the MM16/MM20/MM24...) vertical bandsaw we're talking about, not a shaper with a 5lb tool spinning at 5,000rpm or a table saw with a 16" blade. If you have a decent mechanical footbrake that has an interlock switch, do you really need an electric or magnetic motor brake? It's a bandsaw, a machine with three moving parts. Speaking only for myself, in 11+ years of using bandsaws of this level, I cannot recall a time where I needed to be able to stop the machine "better" (however one might define that). How complicated does it need to be in order to do its job? Do you really need to turn a Honda Civic into the space shuttle to resaw some wood? On the list of things you could ask for on a bandsaw that would make it cut better, there is lots of other stuff that would come to mind before this. Just my 2-cents as always.

Erik

+1. The foot brake on my MM20 will stop it in about a second if I really feel the need to jump on it. I have 3 other euro machines with electro-mechanical brakes (J/P, shaper, tablesaw) and the only one that I really care about is the shaper. The J/P is nice to have I guess, and the brake on the table saw is of no value to me. The biggest downside to the E-M brake is the need to have the saw powered to release the brake to service the machine.

As I said in the removed thread though, at this point it's all academic.

Scott T Smith
05-22-2015, 12:43 AM
I have a Grizzly G0513XB2 bandsaw, and the electrical brake works extremely fast and extremely well. The stopping time is 1 -2 seconds. It is much superior to my previous bandsaw that had a foot brake.

No problems with it whatsoever in 6 years.

Allan Speers
05-22-2015, 12:59 AM
Erik, could you just give him a MM so we can be spared from all these threads?


I'll gladly take the MM, but here's an idea: If these threads bother you, don't read them.

Genius, I know.

Jerry Wright
05-22-2015, 6:49 AM
So Alan, you don't mind trashing the perceived quality of a vendor's customer service effort. However, when the quality of your posts are challenged, you are indignant??? Wheeee!