Makita announced a new 5″ paddle switch angle grinder with AC/DC switch, 9558HP, but it’s not exactly what it sounds like.
New angle grinder offers high power with low weight and multiple power options
Multiple power options?! Does that mean… no, it doesn’t.
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To me, AC/DC power suggests corded + cordless, but that’s not the case here.
Makita USA says:
The user has the option of using a simple slide switch to allow the 5” Angle Grinder to operate off of either AC or DC power (with a generator), depending on which power source is available at a job site.
I asked Makita USA’s communications manager to elaborate upon the “DC power with a generator” part but they never responded.
Does that mean it can be used with inverter and non-inverter generators? How often are non-inverter DC-output generators used at jobsites where a 5″ angle grinder might be used?
Makita also says the grinder is:
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idea [sic] for users in the electrical, mechanical, and plumbing trades. It is also ideal for users in fabrication shops allowing users to perform a wide variety of metal grinding applications
It features “labyrinth construction” to protect the drive gear and bearing from contamination, as well as “zig-zag varnish on both sides of the armature coil.”
They add:
The 5″ Paddle Switch Angle Grinder gives the user 7.5 AMPs plus 10,000 RMP [sic] in a 4.5 lb grinder
- 5″ wheel size
- 7.5A motor
- 5/8″-11 spindle
- Paddle switch
- 10,000 RPM
- Weighs 4.6 lbs
Price: $114
Discussion
I don’t know if it’s because power tool brands rarely launch new corded handheld tools anymore, or I just haven’t been exposed to non-inverting generators very much, but the AC/DC switch isn’t very clear to me.
The new Makita angle grinder looks a lot like the Makita 9557PB, a similarly-sized and featured 4-1/2″ grinder. The new model has lower RPMs, which makes sense as it takes larger wheels.
The 9557PB also has an AC/DC switch for “use with alternative power sources.”
Looking across Makita’s broader corded angle grinder lineup, they ALL look to have an AC/DC switch.
If you need more power than the 9558HP, Makita also has a 4-1/2″ and 5″ paddle switch angle grinder (GA5052) with AC/DC switch and 11A motor at the same price point.
The AC/DC switch is beyond my familiarity – which is probably why I initially thought “multiple power options” meant this was a corded/cordless model, but seems similar to Makita’s other grinders.
I’m guessing Makita’s goal was to be consistent with the rest of their lineup.
Is an AC/DC switch something you’d look for in a corded angle grinder?
Matthew Wootten
Most welder/generators only put out 110v DC. So someone who does pipeline work or on site welding would need a tool that runs on DC power. I believe Dewalt and Metabo both offer a DC grinder.
John
Any universal motor will run off that though, which is what welders have been using. And any regular corded grinder has a universal motor.
Richard
Older style DC generator welders like the Lincoln Electric SA-200 used a DC exciter and only produced 115V DC auxiliary output. This grinder would work with the auxiliary output of these types of welders.
JMJR
They probably just mean that the grinder is powered by a universal motor, which can run off AC or DC power. IIRC, this is nothing special, most regular grinders use universal motors.
I can’t think of any practical application for DC power though, it’s not like someone is going to wire up ten 12V car batteries in series to power this grinder if they don’t have access to regular 120V AC power.
https://en.wikipedia.org/wiki/Universal_motor
Stuart
I’ve used many corded power tools, but none with a sliding switch for AC/DC power selection.
Saulac
Like many had said, it is universal motor on 115 VDC. But no idea why the switch, or what would happen if the switch is in the wrong position.
Stuart
Are other brands’ corded grinders *not* engineered with universal motors?
MM
It is likely a universal motor. Those are actually fairly common for angle grinders, it’s just not that well advertised/known outside the welding trade. The reason is so you can run the grinder off a gas-engine powered welder for use in the field where there is no AC power.
Dave
Milwaukee has a corded bandsaw that operates on the same principle. Though I don’t think it has the slide switch.
D3t
I think they(at least used to) make 7 or 9 inch grinders the same.
MM
It is a common feature for corded die grinders as well. Basically if you can imagine a welder needing it then it can probably can run on DC. I’ve seen the feature on portabands, drills, bandfiles, abrasive chop saws, all manner of grinders, and even some circular saws.
Chris
In the world of battery powered tools this seems almost useless for electricians and plumbers. I’m not sure what use cases they foresee, but they must be very few and far between considering any job site I’ve been on.
Welding is the only trade where this seems like a plausible use.
Jim Felt
Stuart.
Is it just me or is Makita North America literally lost at sea? Too many layoffs after years of apparent management discombobulation? (I just love getting to use that word. Thanks to Makita).
Stuart
I would more describe them as a sinking ship.
They’ve got new leadership, and that might help them patch the hole and bail out water.
Jaotman
Variable speed
Stuart
Fixed speed.
Kentucky fan
It’s meant to work on older welding machines that only output dc.
Adam
Maybe not just North America. Have just seen what should be a high torque reviewed on T.T.C, a bit taken aback. Cannot believe they released such a tool. at such a price, with such a mangled designation. Add this to the lack of LXT battery development along with their apparent disregard of what is the most profitable market and you are left with a feeling that Makita is being ruined from the top
Eliot Truelove
Makita never said that Impact wrench was a high torque, and the model doesnt even come up when you search for “high torque” on their site.
There is plenty of room in that tools clamshell for a beefier motor and hammer mechanism, and there are patents for a new high torque, so there may be one on the way that will end up in the same clamshell with different overmold.
It may look like a high torque, but the reduced weight, size, and power but increased RPM from previous versions is for all day industrial installation work like bridge building, metal girder fastening, gas mains, etc, particularly overhead. The increased RPM but lower torque is likely to torque to spec quicker without overshooting.
They even have an electrically insulated Linemans “Utility” model, again, lineman are often working on power lines, transformers, junction boxes etc. overhead.
Similar to how Stu here wasn’t aware that welders use DC powered grinders running off of a welding setup or DC generators, that Impact Wrench is for Industry use.
We must remind ourselves that if we can’t concieve the use for something because we only use a tool a certain way, another similar looking tool may seem odd or not as powerful if we don’t understand it, like this grinder is to those who aren’t it’s target audience. That’s exactly what the Impact is as well, and TTC is an automotive repair technician first and foremost, not an industrial installation tech.
MM
It is true that Makita didn’t advertise that as a “high torque”, but its massive size certainly implies it. There absolutely are use cases for a lighter weight, lower power, impact wrench. But this doesn’t appear to be one. This has the power of a mid-size impact driver, but the size and weight of a full-size model. From 10 years ago.
Let’s say I’m an auto tech working under a car or I’m doing electrical work overhead and I want a smaller, lighter, tool to reduce fatigue. Been there, done that. But why would I pick this new Makita, which is barely any lighter or smaller than their 10-year old full-size model, when a variety of mid-size models, including others from Makita, offer the comparable power but in a much lighter package?
Stuart
I think what Eliot is saying is that the new Makita impact is completely unsuitable for that type of user; he’s saying that it looks like a heavy duty impact but isn’t.
JR Ramos
DC generators are also still very common on ships and the military…I think a lot of aircraft, too. If under load the grinder can eat up more than 12 amps or so, moving to DC source is a better idea. I would imagine the on/off switch on the tool is beefed up to handle higher DC voltages and the connection spike compared to standard ac/dc switch ratings. If memory serves, that reason is why our automobiles use AC alternators rather than DC generators. I don’t know where things stand these days on tractors and farm equipment but I’d imagine that some of those are DC as well.
I think this points to Makita giving attention to industrial users, which they have always done. Joe homeowner and typical trade users don’t need this and probably don’t even need to know about it really.
Jerry
20+ years ago when I was in tech school we had AC/DC grinders and drills. They were meant to be used with an arc welder. It had a DC plug in the front and you could grind your welds (or drill a hole) on what you were working on without stringing an extension cord. The AC/DC ones seemed to have longer cords than the plain AC ones as well, if I remember right which would go along with not needing an extension cord. If the welding lead could reach, the grinder could too.
eddie sky
For welders!
Who with a rattle can and grinder, a welder be!
TomD
Grinders and paint make me the welder I ain’t!
Waylon
People who grind all day long don’t use a battery powered grinder. Just because a tool doesn’t make sense to your personal lifestyle doesn’t mean that there aren’t thousands of cases around to world when it’s the best and only option.
Kentucky fan
Yeah I weld for a living and no one would ever even try to use a cordless grinder for anything other than a quick 5 minute job. Grinders eat batteries and the huge batteries that actually would last are too unwieldy to use. Plus in general you already have the generator with you so there is no need to use batteries.
Ct451
I agree with you 100% but I do enjoy dismissive comments.
I think the confusion here is the “AC/DC switch” which can be interpreted as a switch ‘between’ AC and DC and not a switch that works with ‘both’ AC and DC.
Stuart
Welders absolutely use corded grinders, and often multiples pre-loaded with different accessories.
I’m just not familiar with switchable AC/DC, hence the question.
Do welders often operate DC generators?
Makita doesn’t explicitly say these are for plugging into welder aux ports, they say it’s for AC or DC generators.
All of the modern welding machines I looked, such as the Esab Ruffian, have 120VAC and 240VAC outlets, not DC. DC generation looks to be handled in plug-in welders, and I couldn’t easily find any examples of DC-only generators.
MM
Modern gas welders often have AC functions but that is a relatively new thing. For the longest time the typical “stick welder” you’d see on the back of a welding truck was DC-only machine. The main idea of DC capable power tools is to run off welders like that, for welding on pipeline, oil field, farm repairs, fences, and so on.
If you welded in a fab shop with a roof and AC power you’d be plugging both your grinders and your welders into the grid. If you were welding out of the back of your pickup you’d have the grinder plugged into the welder.
Kentucky fan
Mainly pipeline welders use ancient Lincoln machines that have the correct arc characteristics for running 6010s and 8010s downhill for their specific purpose that is what they use and most of them will never change. Those are the machines grinders like this are designed for and those dudes are stuck in their ways is a way you would never believe lol. Those machines only output dc and usually don’t even output the correct voltage either they will be close but not actually within the parameters that would be acceptable on even a modern non inverter generator much less mains power.
The issue with machines like that little esab you reference is even though it will say it is designed to run 6010s no inverter will give the actual characteristics those guys want. Generally unless you are getting into diesel machines none of them really stick weld that great. Granted I’ve done plenty of great welds with bobcats and rangers but it isn’t ideal. The machines like you speak of are essentially a generator that can kind of weld vs a welder that can generate if that makes sense.
With all of that being said the guys running machines that would need this generally only use 9” grinders 7” at minimum. So this seems like an odd thing for Makita to include on a grinder this size.
Stuart
Thank you (and everyone else)!
All of that does make a lot of sense!
Kentucky fan
You are welcome it was cool to be able to share something from my niche of the world with everyone here for once lol. Normally I’m learning from you guys especially with woodworking tools and brands I’d never know about.
Nathan
Does it say it runs 115vdc? I wonder if it’s a brushless control motor with load sensing and it runs on either AC or 24v DC.
Does it say it’s 115v and 60hz or any indication? Meanwhile like the others my first thought was welding.
Peter Fox
To clarify and expand a bit more on the AC/DC switch confusion.
All universal motors can run off of either AC or DC power. They are essentially a series wound brushed DC motor with some modifications such as compensating windings to provide better performance with AC power. Most if not all corded power tool motors will run fine on DC power, The complete tools however are a different story.
The problem that prevents most corded power tools from running on DC is usually the variable speed trigger switch. Most are based on simple SCR based controls, much the same as dimmer switches. by delaying when the SCR turns on during each half of the AC cycle they can control the effective power that is allowed to the motor and thus vary the speed. Unfortunately SCR’s require the voltage across them to drop to 0 or less to allow them to reset. This doesn’t happen with DC. This means that once the tool is switched on it will take off at full speed and the trigger would no longer function.
Because of this issue pretty much every AC/DC capable corded power tool has a simple on/off switch as these do not care the type of current they are switching. As most older corded power tools did not have variable speed it was much more common for them to advertise being comparable with AC and DC power.
In the modern era where corded power tools are growing less and less popular maintaining older models that lack even variable speed let alone releasing new models might seem weird. But it really means that some one is paying attention to a niche that still exists and someone needs to fill. In this case grinders that will run on DC output only engine driven welders.
Bubb Rubb
GREAT answer!
kri
From the parts diagram this one has no controller i cant even find the acdc switch. compared regular 120v has controller maby its just a Raw angle grinder with not added tech just brushes and a cable
kri
Maby the stator in the motor is diffrent
neandrewthal
It just means that the one switch it has is capable of switching DC, which requires a more robust mechanism. AC is “easier” to switch because the voltage hits zero 60 times a second.
Mark
I just want to shout out the comments section here. Once again, Stuart (as well as I) did not know about something, he puts it out to us in the mailing list and MANY of you come in with helpful information regarding welders and their uses of a tool like this.
I can’t think of a single other “comments section” I interact with leaving me with positive outcomes like learning practical information on a regular basis.
AlexK
Second that.
I read every comment and learnt something that probably won’t come up again in my life.
If it does, I might be the only non welder to know something about this.
Chip
Ac-Dc is hp-torque.
An airbus 380 has 1.1 million hp,and moved by a tugger with probably around 500hp but more usable torque.
Dc is used in electric vehicles, ac is not.
Older DC welders often cost more than new modern multi process,and are rewound/rebuilt many times.
A 4inch grinder in ac/dc seems rather strange in a non-flathead use for small projects.
Robert
Maybe AC/DC toured Japan a lot back in the day, and made an impression on the CEO when he was young.
Rumor is “You shock me all night long” is why Makita introduced vibration reduction to their line-up.
Robert Adkins
At first I thought it was for use in North America and across the pond, but those funny DC plugs are 220v, not 120v. I’m out of ideas now.
SteveP
When my ancient Makita 12V NiCad battery drill died, I gutted the casing and wired it to run off a cigarette lighter plug
Victor Hidderley
Hi, Stuart,
Australia Calling
Re the function of the AC-DC selector Switch on the Makita Angle grinder.
I suspect It is an Arc Quenching device for the DC mode.
Based on experience on mains supplied appliances
So, on AC 110 Volt 60 HZ 10 Amps the arc is small and easy controlled with a good AC trigger switch
Now DC 110 Volt 10 Amps new ball Game! Same Switch expected to switch DC
Which has a great ARC on the switch for the Same Current!
So, I suspect Makita have used an electronic filter to reduce the ARC and prevent damage the Trigger Switch
Yes to all that mentioned it a universal motor true But and don’t confuse 18 Volt Appliance with Main Powered Appliances
Best Regards Vic