Variable Speed Angle Grinder - for the homer

[bradlys]

I have a HF $10-20 angle grinder. It spins at some ridiculous 10k+ RPM and that's the only mode it has. The only way to make it go any slower is to just dig it into the work to where its 5amps gets completed gutted.

I've been using wire cups and what not because I'm refurbishing a 100+ yr old iron bed frame. However, the things are disintegrating as soon as the thing gets up to speed because - well - they're not made to go that fast all the time. So, a lot of wires are flying even on the cupped wire brushes. On top of that, the grinder is a bit underpowered even for this operation. (Even on just a 3" cup)

So, I've since gone the way of the rabbit and burrowed a nice hole. What's the best variable speed angle grinder out there? (One speed clearly doesn't work because some items require different speeds) What's someone like myself who might use this angle grinder for any numerous series of tasks left to buy? I've been eyeing a Metabo WEV15-125 HT. It's about $170 + tax. I would buy one used or the equivalent but there are basically none available in my area and I'm impatient. I do not want to own multiple angle grinders if I can help it.

 

[ItsNemo]

Can't help you with the variable speed part but will say that owning multiple grinders is something everyone wants! No changing wheels all the time Personally I have 2 cordless and 3 corded grinders of various styles and sizes, use them all.

 

[justintendo]

get the metabo..nice unit for the money

 

[dogdog]

For variable speed flap wheel and wire cups... I used the HF 7" variable speed polisher... the threads and every thing else fits including if I wanted to do grinding as well with it.... but just keep in mind... I doesn't come with a guard... so might not be scream too well with safety personals...

https://www.harborfreight.com/7-in-10-amp-digital-variable-speed-polisher-62297.html

 

[amh]

A brush motor speed can be lowered (upto a point, without losing too much torque) in a couple of cheap ways:
1. A Variac (variable transformer) if you have one.
Or
2. An SCR/Triac circuit with sufficient current ability. (It's like a high current dimmer)

Horror Fright used to sell a "router speed controller" box that claimed 1800 watts capability.

I think you can still buy them on eBay and amazon for under $20.

https://www.amazon.com/dp/B002MLE01A/?tag=atomicindus08-20

If you want a cheaper solution, you can buy a high power Triac circuit on eBay for under $4 and build an enclosure for it, but takes too long to ship from china. (Can be bought for about $6 on amazon if you want it quick). That is probably what is inside the router speed controller. They also sell 4kW version, some even partially enclosed, just make sure it can go down to 50v or so, the high limit is usually 240v (ok for 120)

https://www.amazon.com/dp/B002MLE01A/?tag=atomicindus08-20

For some reason pics did not show, so I added amazon links.

 

[Dumber than lumber]

I have a 5” variable speed Fein. Some will poo-poo my choice, but the 4.5 inch models seem to be built to a lower standard and price point.

 

[neophyte]

Variable speed tools, particularly higher rpm tools like angle grinders, should never be used with accessories with maximum rpm ratings lower than the maximum rpm of the tool.
There are a few reasons for this.
A dial speed control can accidentally get bumped or turned, increasing the rpm of the tool, or vibration can cause the speed control to self adjust( a problem on old Dremel tools), or the speed controllers can fail, causing the rpm to ramp up to the maximum speed.

Also, the size of cup wheel you’re supposed to use on grinders is usually smaller than the size of the wheel the grinder is made for.
4.5” and 5” grinders usually have 2”-3” wire wheels listed as accessories by the grinder manufacturers.
4” wire wheels are usually listed for 7”+ wheel grinders.

When in doubt, check the rpm listed on the wire wheel.

You can also get “Encapsulated” wire wheels, were the bristles are encapsulated in a bonding material, which should help with stray wires.
https://www.weilerabrasives.com/pro...wheel-014-steel-fill-5-8-1-2-arbor-hole-35117

 

[Slednut]

I really like this thing, it runs so smooth.

 

[david3921]

A brush motor speed can be lowered (upto a point, without losing too much torque) in a couple of cheap ways:
1. A Variac (variable transformer) if you have one.
Or
2. An SCR/Triac circuit with sufficient current ability. (It's like a high current dimmer)

Horror Fright used to sell a "router speed controller" box that claimed 1800 watts capability.

I think you can still buy them on eBay and amazon for under $20.

https://www.amazon.com/dp/B002MLE01A/?tag=atomicindus08-20

If you want a cheaper solution, you can buy a high power Triac circuit on eBay for under $4 and build an enclosure for it, but takes too long to ship from china. (Can be bought for about $6 on amazon if you want it quick). That is probably what is inside the router speed controller. They also sell 4kW version, some even partially enclosed, just make sure it can go down to 50v or so, the high limit is usually 240v (ok for 120)

https://www.amazon.com/dp/B002MLE01A/?tag=atomicindus08-20

For some reason pics did not show, so I added amazon links.

I have one of the HF Hercules grinders with a cut off wheel set up in it. I was using it to cut off sway bar links on my car and the high speed made it jump around while attempting to cut. I plugged it into my router speed controller and slowed it down. I was able to adjust the speed as I went deeper into the cuts. Worked well for me in this situation and I didn't notice any lack of torque.

 

[bradlys]

get the metabo..nice unit for the money

This is what I ended up doing. I don't want to fiddle with router speed controllers that only work to a certain limit and what not. Looks like a lot of hassle.

Whatever. $185 after tax. Should be here soon. I'll end up keeping it for 30+ years and hopefully get much use out of it.

 

[seber]

Get a brush rated for the grinder. They don't all fly apart at high speed. I use a four inch cup brush on a high speed grinder fairly often. It has lasted a very long time. I do have to pull a few wires out of my pants legs after an extended use.

 

[justintendo]

This is what I ended up doing. I don't want to fiddle with router speed controllers that only work to a certain limit and what not. Looks like a lot of hassle.

Whatever. $185 after tax. Should be here soon. I'll end up keeping it for 30+ years and hopefully get much use out of it.

:

enjoy your new grinder. Hard to lose with quality tools

 

[KenC]

Back to the real problem. I'd bet it is wire wheel quality that is causing the flying bits, not too much speed. I almost never use a slower speed when grinding or wire brushing, only when sanding paint to avoid clogging thedisk.

 

[bradlys]

Back to the real problem. I'd bet it is wire wheel quality that is causing the flying bits, not too much speed. I almost never use a slower speed when grinding or wire brushing, only when sanding paint to avoid clogging thedisk.

I don't know how quality they are but they're dewalt branded. I don't know who their supplier is. I think they all say they're rated for over 10k RPM but they still like to fling and spread apart a little too easily, IMO. I definitely never let it just free-spin, I have to keep them engaged with the subject to slow it down. On top of that, the grinder I have from HF does bog down too easily. The Metabo will be something like 3x the amperage, I think. Should just be a better experience.

 

[82c10step]

https://shop.harborfreight.com/medi...b33525d08d6e5fb8d27136e95/i/m/image_18028.jpg

 

[subroc]

I use more than one tool with a variety of wire brush sizes and shapes when I mechanical clean rusty surfaces.

 

[tarbellb]

Metabo
Fein


Im a big fan of the Brushless corded Metabo HPT (formly Hitachi) G12VE

also a good "deal" is the VS Bosch sold at HD for ~$120.

 

[Stephenw]

I have a Metabo 5” variable speed grinder. Awesome tool, worth the money.

 

[IndyGarage]

I really like this thing, it runs so smooth.

I have one of these - probably the best grinder I have that is not a Metabo, and really is close to one of them...