Peeking at a Milwaukee Brushless Motor
Here’s a rear internal view of Milwaukee’s M18 Fuel brushless impact driver. I removed the back cap, or what I thought was the cap, and the fan, permanent magnet, and drive shaft came off as one piece. I don’t have anything else to add about this, or why I was peeking inside the tool’s housing, but I thought you’d find the image interesting.
Dewalt 12V Max Brushless Current Draw
I also learned something interesting yesterday, about Dewalt’s 12V Max brushless screwdriver, and how it draws more than 3-4A of current to spin up without load. I thought it’d be less, but at 4A that’s what, 50W under no-load conditions? I have more measurements to make.
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Workshop Cleanup
Today’s a workshop cleaning day, and it’s a tough one because I’m now trying to determine whether to go with cabinets, shelving, workbenches, or a pile of milk crates.
I had went with a custom shelving solution out of 80/20 extrusions, but the slope, humidity, temperature, or other garage environmental conditions caused the rubber-padded swivel feet to fail. The top rails are 1.5″ x 1.5″ and so there’s no room for a larger bracket to accept larger-stemmed swivel feet. I could have better success with larger feet than what I used, but at significantly higher prices I’m not willing to pay.
So… I think I’ll redo things, perhaps with shop-made racks or what-not until I can figure out a sturdier metal-based solution. I might have to build an assembly table that doubles as a garage for my kids’ Power Wheels car, which is currently stored vertically in my 80/20 shelving unit.
It’s funny, I have similar rubber-padded swivel feet in the basement, and nothing slid apart, so why did it happen in the garage? I guess if environmental conditions are just right, combined with the swivel feet resting at an angle, the adhesive fails and allows the steel foot to slip.
Olight Sale
Olight’s flash sale is still ongoing. Read more about it here. Visit the sale page directly. If you miss it, don’t fret; with how things have been going, there will likely be another flash sale next month. And if you’re not into Olight, we’ll have a bunch of different lights from other brands to recommend for and against in coming weeks.
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Social Media Posts
Here’s some of what ToolGuyd has been posting about to social media:
You can follow us on Instagram here: @ToolGuyd
That’s right, we were *finally* able to work with Instagram to get the ToolGuyd username.
What’s an Engineer Hammer?
According to Wikipedia and an early 1900’s reference on locomotive supplies, engineer hammers were part of a railroad engineer’s toolkit.
Today, engineer hammers, such as this Estwing, are essentially shaped like mini sledge hammers. I have found that they are generally longer than drilling hammers, and with narrower sledge-shaped heads. Drilling hammer heads are a bit stubbier, such as on the new Milwaukee:
If you haven’t already seen it, here’s our post on the new Milwaukee drilling hammer.
Tool of the Day: Seville Wire Shelving Cart
Today’s tool of the day is this Seville 3-tier wire shelving cart, priced at $74 via Amazon. I bought one back in April for the same $74.04 price, and it’s quite versatile. Right now I’m using it for gardening supplies, but it’ll be used as a tool and materials catch-all once the season is over.
It measures 30″ wide (34″ with the handle) x 18″ deep x 33.5″ tall and has a 500 lb weight capacity. The shelves all have raised lips, which helps keep things from sliding off, and all 4 casters swivel.
Lyle
A picture of the failed swivel feet and your 89/20 racks would be nice.
David Zeller
I wanted to see that, too!
Rx9
Stuart, have you heard about the Briggs and Stratton bankruptcy?
It’s definitely going to change the nature of the OPE market.
I hear stories that electric ope was a minor factor and excessive debt was the real driver.
Stuart
I have read about the bankruptcy, but lack enough context and insights for a post just yet.
A private equity firm agreed to buy their assets and Briggs & Stratton plan to continue operating.
The investment firm said:
“KPS intends to grow the new Briggs & Stratton aggressively through strategic acquisitions. The new Briggs & Stratton will be conservatively capitalized and not encumbered by its predecessor’s significant liabilities.”
That’s also going to impact the industry, but it’s uncertain what the end-game will be – will the investment firm seek to grow the company for direct profit, or to potentially build up and then sell for a greater amount than the sum of their acquisitions?
rmkilc
I have always taken apart every tool before I use it including all of my Milwaukee impact drivers and wrenches, saws, grinders, etc. So far, two of my tools weren’t assembled properly but I easily fixed; the 0880-20 wet/dry vacuum and the 2725-20 string trimmer. The vacuum had a seal that wasn’t seated properly and was pinched between the mating surfaces so there was an internal air leak and the string trimmer’s fastener that tightens the motor mount around the main shaft was floating around inside the case.
Plaingrain
Speaking of tools! Home Depot has a Rigid 2 speed drill driver kit on sale. $79.97(64% off). Kit includes drill/ driver, (1) 2amp hr battery, charger, tool bag, & a bit set.
Alex Peel
I have a Laguna bandsaw and I highly recommend their Resaw King line of blades with carbide tips. It gives a very smooth cut for resawing.
fred
I too have a Laguna – 16 inch saw – but have used Wood Slicer brand blades with very good results:
https://www.highlandwoodworking.com/search.aspx?find=slicer
I’ve not tried the Laguna Resaw King blades – but Laguna makes good stuff.
fred
I should have added that proper blade tension is critical for good bandsaw blade performance – and you can see the results of an under-tensioned blade particularly when resawing. I always wondered if I should invest in a tension gauge – but they are pricey and so far I’ve resisted the urge.
Wayne R.
“Resawing” is what please?
fred
English is marvelous in its ambiguities.
We would not say I’m resawing length of 2×4 although that parlance might be correct – since the 2×4 is in fact dressed lumber out of the sawmill – and cutting one to length might be said to having re-sawed it.
Back to what’s generally called resawing.
Its taking a piece of thicker wood and cutting it into thinner sheets. So I might have a hunk of 8/4 maple (1-13/16 thick) that I want to turn into book-matched pieces for a cabinet top. I can set my bandsaw fence to cut it into two equal pieces each about 7/8 inch thick (29/16 divided by 2 – minus the kerf of the bandsaw blade. That’s what’s called resawing
Frank D
If I were to only work in the garage and perhaps do minimal car repairs and DIy, then I can see a use for cabinets. With multitudes of tools for most trades and plenty of supplies, it is all living on wall to wall shelves, a lot of stuff now in ridgid crates and cases. It would be a lot more red, if MW did not insist on doubling the price over ridgid, just because it has slide locking feet … if they charged let’s say $10-15 extra … but it is 25 vs 50, 30 vs 70, … sigh
I have two of the seville carts from Sams. The 10yr old one is easily 50% stronger and beefier than the one I got two years ago. They really cheapened them or switched factories.
DRT
I have quite a few of the full-size Sams Club Members Mark/Seville racking units. The ones I bought last month were made in Vietnam. I don’t recall where the older ones were made, but pretty sure it was somewhere else, like China. The threading on the poles seems a little looser on the new Vietnamese ones, but other than that, I see no difference. The carts could very well be a different story.
Frank D
Yes, my comment was on the pictured cart. My first one holds all car detailing stuff and some tools. The second I turned into a mobile smoker base.
I think the tall racks are still consistent, from the looks of it.
I have a few of those and I love them, since they’re on wheels. The only downside is, if you need to re-adjust shelf heights, it can be a bit of a chore.
Frank
Those Facom wrenches are available from Mac Tools.
Koko The Talking Ape
Thanks for explaining engineer’s hammers, Stuart!
Re Milwaukee motor, I’m always struck by how thin the insulation around the wire in the windings is. I know it should be thin, to maximize winding density. But it seems to be just a coat of varnish or something like that. Doesn’t it ever crack or get nicked?
Re startup amperage draw: I guess there are two things going on: one is overcoming the opposing induced current created by the changing electrical current (is that impedance?) The other is overcoming the rotational inertia in the spinning pieces such as the shaft, chuck, magnets or windings, etc. I wonder if motor designers ever try to reduce that rotational inertia to reduce start up current draw. That might matter for certain applications.
IJK
As someone who has taken apart a bunch of electric motors, from RC car sized up to 1000 HP for rubber mills, yes, it’s basically just a thin coat of varnish. You’ll see it in transformers as well, although on the bigger motors they might add another coating over the whole assembly. What surprises me more, is the thickness of the wiring. But I would guess that’s more for the amp capacity than anything.
For startup amperage, I’m curious if it drops off after getting up to speed. I’m sure there’s inertia in there, plus possibly releasing a brake, along with general baseload friction on bearings and whatnot. As for your hypothesis on it being due to opposing induced current (usually called Counter-Electro-Motive Force, or Back EMF), that’s an effect that usually increases as speed/load goes up, whereas normal startup current would spike and then drop off to account for the inertia.
IJK
Since I can’t edit, I forgot to answer your question about cracking or nicks. Yes, they can, and do, get cracks in old age. Usually due to embrittlement and vibration. Same with nicks, if a bearing gets out of tolerance letting the rotor hit the stator, or debris gets inside. When either happens, it makes for a pretty spectacular failure, at least on the larger motors. You’ll see shorts, arcing/scorching, and on 3 phase motors it can single phase itself which can let it continue running but poorly.
Koko The Talking Ape
Thanks for both your answers, IJK.
Re vibration: you’d think they would dip the entire coil assembly in something like epoxy to hold the windings more firmly in place, and reduce those cracks and nicks in the insulation.
Re wire diameter: I guess it’s a tradeoff. IIRC, thinner wire allows more turns, which means more torque generally, but also more power lost to electrical resistance. Further, the lost power is turned into heat, which is bad in other ways. Am I wrong?
Stuart
I’m not talking about start-up but no-load draw. I was seeing 4A draw consistently, but numbers kept changing and I didn’t get a solid read.
When you over-draw a power tool, and safety protections don’t kick in, the smoke you see is the varnish melting off.
It’s surprisingly thin, but that’s true with most motors and it does the job. The wire density likely helps with cooling as well.
IJK
My mistake on the mis-read then. That is pretty high. I wonder how that no-load compares to max output. Also curious about no-load draw on other tools and how they compare.
As for the wire, I guess that photo was a bit deceptive for me. I thought it was surprisingly thick. I might have to grab my buddy’s 24v kobalt and see how it compares, I suspect the wire will either be thinner, or more wraps on the windings.
Drew M
“good” magnet wire is “class H” and the coating on the wire is similar in chemical composition to Kapton tape. It is VERY durable and actually quite annoying to remove from the wire.
After winding, “good” motors will have the wire “painted” in a resin to secure the windings against movement/vibration.
The Milwaukee motor above is likely not wound with class H wire due to the color. It is hard to describe but the coating is typically a darker color.
andy
4A does seem like a bit. That means run time would be around 30 minutes with no load.
Corey Moore
I’ll never forget handling my brand new dcd790 in bed and thinking, “I wonder what the transmission is like in this fancy brushless stuff” then watching horrified after opening it, chuck skyward, as it rained more tiny gears than I could have thought possible of fitting in there, all over my poorly lit nightstand. Incidentally, that event was also how I learned that dewalts website has downloadable exploded views for tools on their product pages haha According to the fella that has it now, it’s still punching holes in stuff just fine.
Nathan
hmm – what has you handling a drill in bed.
On the startup current – how long did that pull for. 50 ms or less? Curious as to the rest of that story. I bet it’s mostly mechanical inertia wonder how that tests with a bit in there. Also I bet it’s capped at a value too to keep from overspeeding the drive.
I could see where a strong motor would potentially wrap up to speed so fast it might damage what it attaches to.
Is there a way to see the pictures with out instagram?
Corey Moore
Had new tool, getting in bed. That’s about it. Do you not carry around and excessively inspect (read: play with) new tools, when you first receive them? I’m not ashamed to admit to throwing a new hand tool in my pouch or pocket the first few days I have it, even if I have no ideas or plans to use it lol I like tools, that’s how I ended up here?
Frank D
The only way power tools would end up in bed (besides to build a bed frame), is if ALL I had was a small room and a bed …
Bad enough that many tools start out in the kitchen after package delivery.
Corey Moore
All I had was a small room and bed haha My tool bags were next to my nightstand stand, and my chargers were at the doorway. Grab my crap every morning at 5 and someone would pick me up at the end of my driveway for work. That was awhile ago, couple jobs, couple homes lol Company truck now, a crew, a lot more tools and storage, but those are still fond memories for me, trying to explain what was so good about whatever new tool as she pretended to get it or care and tried to read or whatever. New tools were a huge deal when younger, took research, convincing, and saving up.
Luckey Dodge
Just bought the Costco tall tool box for $ 600.00. Had to drive from Huntsville to Nashville to get it. My Town & Country handled the 2 sections quite nicely! Sooo heavy!
Now I can unload my 2 Craftsman tool boxes and make room for this new monster.
The tool box was made in Taiwan, it seems to be overbuilt.
I hope this new tool box will give me as good service as the Craftsmans. The metal is quite thick and has ball bearing drawers with “close magnets”.
As time goes on. Next, I want to get the 82 volt Snapper battery powered lawn mower. It has the Briggs and Stratton battery system. I hope I am making the right decision.
Drew M
No load power draw is a good way to compare the efficiency of different brushless motors however, simply measuring the current is not enough information to form any conclusions. It is actually a fairly complicated field of science.
One of my favorite things to do is find motors that are “giant killers” in that they’re inexpensive and yet outpeform motors costing 10x as much from name brands.