BOLTR: RUN TEST DeWalt Compressor | Stupid Idea
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- čas přidán 19. 05. 2019
- I test the Dewalt 60V air compressor. It doesn't blow, it sucks.
I couldn't get anywhere near the performance claimed on the box. What am I missing? Thank you for your help making these VJOs. Early access here: / ave - Věda a technologie
Never had anyone ask me why there are bubbles in a gauge, lots of people have asked my why there is hydraulic oil spraying out of one though.
NICE, LMAO.
Would seep glycerine out the rubber cap more likely. A non-dickered gauge that wont read zero in a very hot or cold enrivoment can be helped to zero by gently lifting the rubber cap and equalizing the pressure.
@@mulletjocks That's right. Most gauges have a little tit on the center of the rubber cap that's supposed to be cut off after the gauge is installed to relieve any pressure
Thanks for editing the loud bits out. It's nice not having to play the game of "let's not go deaf" with the volume buttons.
Enginerd here. For rotameters (the type of flowmeter you are using), to get the Standard CFM (SCFM) you need a correction factor based on the temperature and pressure (just google rotameter correction factor). You're supposed to use the pressure and temperature coming out the rotameter outlet and compare it to standard pressure/temperature. You're really reading CFM off the front of the rotameter (it's only really SCFM if the outlet is room temperature at room pressure), so for the "standard" cfm, you need: SCFM = CFM*sqrt[(P/P0)*(T0/T)]. Gotta use absolute units (psia for pressure and Kelvin or Rankine for temperature). We'll say standard pressure is 15psia and standard temperature is 527R (68F). Assuming the first point is 0.8cfm at 55psia (40psig), and you are at room temp 527R (68F), we get: SCFM=0.8*sqrt[(55/15)*(527/527)], and get SCFM = 1.5. Actually not bad! This is why rotameters are usually set with the outlet at room pressure, so they don't need to measure the pressure after it. I'm actually angry that they didn't teach me this shit in school. I had to find out at a job, which was kinda embarrassing.
For inflating a pool float, this would be slower than a distracted bikini model using a foot pump while wearing flip-flops.
That is a brilliant comment.
Not as much fun to watch as a distracted bikini model using a foot pump while wearing flip-flops.
@@blueferral3414 Foot pump? Need to up your game a bit. She can put her mouth on that valve.
@@sireuchre First, the foot pump was halnywiatr's idea. Second, not nearly as much jiggling with your idea.
A foot pump? bah, you can't pair a bikini model with a foot pump, you use a standard floor pump that is unusually short.
Yeah, $200 buys one hell of a heavy gauge extension cord.
For less than $50 you can get a 5 gallon refillable air tank. That's how I got into air tools when I couldn't afford a compressor. I'd fill it at the gas station for free and ran an 18 gauge air brad nailer. Could get 50-100 shots on each fill.
Drove around for 3 months with a refillable air tank that I topped off in the morning using a friend's shop compressor. Used it to refill a tire that I refused to replace before I got rid of the car. That tire would go flat after just a couple hours.
@@AlGoYoSu When I was young and really, really poor, I did the same thing on my car. But, all I could afford was a $7 bike pump. Pumped up that tire every morning for months!
Or use a gas powered pancake compressor......like every carpenter in construction.
@@kw9849 Haha, I did the bike pump thing before and don't envy your situation. Used it twice for car tires in emergencies (no donut, too flat to drive on), and thankfully never again.
You measured flow in CFM at 90 PSI, but the box reported SCFM which is normalized to 1 atm and 70 F.
In other words, the flow meter should be the last thing in your stack.
Or just convert the flow rate at 90 psi to a rate at 1atm... multiply by 15?
@@mikeymasi
So use mass flow. kg/h
@@mikeymasi flow meter last and intercooler in between. I guess.
Don’t forget wet bulb factors, and psig
I know nothing about any of this....
But this all still seems wonky to me. can someone explain _What_ is the difference here?
The box states 1.2 SCFM at 90 PSI, right?
(2:18)
And the flow meter says it Measures in SCFM(2:36), right? Which says
SCFM is not CFM. SCFM is rated flow at 1 bar, this test is CFM at 90PSI. It's a confusing / dubious claim on the box but still quite plausible. So the needle valve is on the wrong end of the flow meter.
Exactly true.
So SCFM isn't Skookum CFM then? Dr. Google says: Standard Cubic Feet per Minute = SCFM = ft.3/minute at standard conditions (1 atm = 14.7psi, 68°F )
@@burgerbirger2221 so if he were running it at 14.7psi you reckon it'd get 1.5? I mean that makes it sound worse, 1.5 cubic feet at 14PSI seems more "fart in a windstorm" than useful...
@@burgerbirger2221 cool name :).
@@genewitch No, the issue is that the air moving past the meter is compressed, so it moves the float based on it's compressed and relatively efficient flow. If the air flow meter was on the open end of the needle valve, and the air in the compressor was 90 PSI, it would expand at the needle valve to 1 atmo, at which point more velocity would be seen in the meter, with the same amount of air mass per second passing through the system.
Since fluid drag increases non linearly, the less dense the airflow the more inefficient the system is, which means more drag, so more lift on the float, and a higher CFM rating.
He cheated the system because be was reading volume passage, not mass passage. He reduced the volume by keeping it compressed through the guage.
When it comes to the battery powered compressors and chainsaws it almost looks like the manufacturers didn't even consult with the folks who've been designing the traditional versions.
output through the flow meter would have to be regulated at the output PSI before passing through the flow meter. if you put the needle valve on a downstream side in order to regulate the output pressure your air density is high as it passes through the flow meter , however the velocity is too low to carry the indicator up the meter as, I observe you have it configured
It doesn't matter either way. The denser the air, the more drag it exerts for a given velocity. They are calibrated for scfm which is equivalent air volume at standard temperature and pressure. Calling these volumetric flow meters is not entirely correct, they measure mass flow.
@@Worrsaint I can't quite grasp it, since kinetic energy is J=1/2mv^2 shouldn't the higher velocity impart the square of the velocity to the plunger?
So a low mass at high density with low velocity has a little energy while the same low mass at low density with a higher velocity should be higher energy.
@@ChatNoirLe That would be the energy of air. It is still moving past the plunger so there is still energy in the air. The inside tube is actually tapered. So as the plunger goes up, the effective area around the plunger gets larger and creates a larger effective orifice. The air drag around it creates a pressure differential. There is higher pressure under it than above it due to the drag. You can actually use that for water and use a conversion factor. They sell bodies with different ball/plungers of different weights for different flow ranges and fluids. They generally just have a scale that are not direct read. It gives a value that you look up on a chart. I worked in a chemical plant and we used quite a few of those both going to atmosphere, and also at higher pressure.
@@Bodi2000 It is normalized to STP. The fluid does not have to be at STP. Read my other comments for how these work.
This is what I thought too, regulated BEFORE the meter to 90 psi. Not after. And consider; in the test configuration, wouldn't this mean even lesser performance than marketing stooges say on the box?
I've been watching your channel long before I started working at Lowe's. And now that I do work at Lowe's, I mention little things about certain tools from this channel. Gets people to think about what they are doing project wise.
AvE = the best linguistics professor I've ever had!
This was a great evaluation, especially the cost analysis. It brings into question whether any of these cordless tools are really loss leaders i.e., sold at or below cost in order to stimulate battery sales. It would be similar to how video game companies sell systems at a loss (looking at you, Sony!) in order to stimulate video game sales.
Funnily enough, the cost per kwh of flexvolt batteries is the lowest of the big three. And not even by a small amount. Someone on reddit did a comparison of all the brands of 18v and 20v batteries, the DeWalt 2 packs for flexvolt beat out all the Milwaukee options and Makita isn't even competing. I think hilti and Bosch were among the very cheapest.
@Darth1970Computer printers classic examples.
Another factor besides the ones mentioned below, would be that the shrouding needs to be on the compressor in order for the fan to duct cool air over the cylinder and head. That's why your head temps were so high... just an observation.😉
Your rotameter is calibrated for std pressure and temp. You’re running it at 105 psia. You have to convert the reading by multiplying the reading by sqrt(Pnew/Pscale). Or run the rotameter after your needle valve.
It's very clearly meant as a portable, light-weight, occasional use, ease-of-use compressor. It's pretty much to let you plop in your car to let you have it as a backup where you dont have to worry about having cords long enough or for when you just need like 3 minutes of work and dont want to deal with the cord
not some sort of high-end heavy-use shop compressor 0.o
seems like one of those things where you have to balance the cost of the device against the time/hassle/stress it saves you and decide if your time/stress is worth it
40 balloons per hour would be enough.
I think it's the Canadian air what's the wrong kind for this tool.
Mostly likely that's it. Those Jeezless Enginerds didn't plan for the mosquito-laden, maple syrup-flavored air clogging up the intake filter.
They probably measured in metric PSI and CFM
Clearly they test this using winter air. Even this time of year in Canader they already have spring air.
AvE video on a holiday Monday, I'm getting paid to watch this up here in canaderp, makes me a professional paid AvE watcher...
A touch of nitric acid in the glycerine fixes everything.
only if its fuming
@@sydmushas And in the presence of sulphuric acid.
Can be done with potassium nitrate and sulfuric acid
You just know that if that was paired with the Juicearo the time/space continuum would collapse.
BRB!
Be fair now. This product might have limited usefulness under hypothetical circumstances if it was better designed, engineered, build, and in general thought out. The Juicearo was fundamentally just a scam.
I was getting ready to buy one of these compressors. Thank you for saving me the money and heartbreak.
“Plumb in all directions” something I know I have said many times before, and always instantaneously regretted… Because plum- is plumb.
At least you're on the level.
Morning from the cold and stormy coast of Maine! COFFEEEE TIME!
Morning from stormy north west NB.
Got my stickers the other day 👍 keep up the good work, we appreciate it
Thanks for the heads up on Dewalt batteries. Looks like I'll be keeping my Makita 18 volt LXTs.
Wasn’t planning on buying one, certainly won’t be now. Where would we all be without advice like this. A lot worse off that’s for sure. I cannot thank you enough for the work that you do on our behalf.
Pumps move stuff around, restrictions produce pressure, well said.
You could argue that the force applied across the planes between the piston and air is a pressure and that pressure gradient creates flow which the downstream resistances lower the ability for that piston pressure to be instantly released.
Centrifugal compressors and twin screws are internal compression machines.
They always produce pressure irrespective of any restrictions or lack thereof
Did you just start the video with “what up blood”? Lol omg new level of awesome ave. You have transgressed all cultural lines. No boundaries left uncrossed.
been binge watchin' your videos the past few days after work man, truly top notch, brother. much to learn from your content.
I don't think the series-parallel switching of the 60V batteries would do as much wear as you think. My experience with li-po batteries (which are similar enough to compare) is that nothing bad happens until they get more than 0.1V out from each other. The use case I have is three 3-cell packs being discharged in series to a similar voltage and then those three packs are put into parallel for charging (acting like one big 3-cell pack, where each 'cell' is 3 in parallel). The charging/discharging that happens between them is minimal, as it doesn't take much energy to raise a battery from say 3.2V to 3.3. Also, this assumes there's no balancing happening during 60V discharge.
"Also, this assumes there's no balancing happening during 60V discharge.", The 60V (or ~57) cannot be balanced as all cells are in series. The issue with attempt to balance them with voltage difference would be that the batteries would be hot (it's possible that the tool switches off due to heat rather than low voltage cut off). Indeed 0.1 on 10mΩ would be 10A which is still only 1W per battery, however since there are up to 10cases, that could be 7-8W of heat generated straight into the enclosure.
You make a pretty good argument against all cordless tools at the end tbh.
"What up blood, sufficient time has prolapsed" AvE is the BE$T
Hey, like the informative videos and sense-of-humor and thanks for showing me what my compressor is like inside as well as how it operates...I was curious. I have it and a (new to me) Honda 5.5HP gas-powered, trailer-mounted compressor. The DeWalt is so easy to carry and quick to use, I had to have it! I don't have any regrets and got it for $250 smackeroos...WIRTHIT!!!
While I agree it's not exactly efficient, I've been saved from a lot of pain-staking labor and time when running cords was either not an option, or like banging my head against a spinning, wire-wheeled grinder, ha ha. The power the Flex-Volt system delivers is respectable in my book. I have had DeWalt's Flex-Volt, 60V, brushless grinder for just under a year now and used the hell out of it. With 6" thin-kerf, cut-off wheels it is much faster and smoother than any of my other grinders, corded or not. The corded grinders are much more noisy and rough-running in my perception. I will admit to not having tried cordless Milwaukee grinders or any other brands. Guess I need to look through your video library for a possible hit on those.
I work on docks on the Colorado River and they often do not have power run to them or the power is not in service...but also my wife and I take this mountain-biking and I've had to use it dozens of times to seat tubeless tires repairing desert 'cacti' flats. One of those times, we had a toy-hauler flat from a bolt puncture I plugged and was able to inflate and even though the bead had unseated (and yes, I had to jack-up the axle for that)...so all-in-all, I think this little "special use" compressor has been well worth the trade-off of efficiency for convenience. I'm thinking we saved enough money from not having to do anything with the trailer tire money-wise that it paid for the compressor, ya, that's what I'm thinking alright! lol
Devilbiss/Craftsman had the same wobbly pusher thingy design also but at a purported 5 hp and 3450 rpms.
When the jobsite doesn't have power and you've got a small framing fix these things are awesome. Or for pressure testing plumbing. It's not an everyday tool but they are handy when you need em!
it's a pancake compressor, first thing I though of is roofing, so more than likely this is for minor roof repairs or in a crawlspace where you can get wrapped up in a cord.
As an rc enthusiast i deal with batteries a lot, you NAILED IT on the whole deal.
a lot of ppl don't understand battery's. so many ppl still think dewalt has more power with there 20V MAX everywhere when its just an 18.5 volt pack like everyone else
@@NightshiftCustom problem is the old cordless stuff was NiCad 18v, so I think they labeled 20v nominal for product distinction sake. I still have a NiCad 18v trim saw and right angle drill that I use, pretty sure both 18 and 20v were in production for a few years there but could be mistaken.
Or it could be a marketing gimmick.
@@apersonontheinternet8006 It can't be 20V nominal neither with NiCd nor Li-ion.
@@SinsBird put a meter to the battery, partner. 20ish volts full charge. Sure, fhe tools don't consume that 20v but the naming sure helped not buy the wrong tool before pulling the trigger on some LiIon tools.
@@apersonontheinternet8006 It has to be the nominal voltage on the label, not something else. It's a marketing wank. 'Look, this one says it has 2V more power, it must be better than that 18V POS'
There is a time a place for this compressor, a trim job, inflating a tire on the ranch, fixing a pressure tank at a job site, their lots of uses for a small compressor. This while having many faults is a good option for a lot of projects.
Of course an oily compressor will last longer, but it is the standard construction of an oilless to not have a wrist pin.
AvE you are not paid to lie. That is why you can't duplicate their claim.
They probably did a very simple calculation what looks right instead of actually testing the thing. Of course, nothin' wrong with the calculation, but it's got no way in hell of predicting the effects of their bad design, especially with that rockin' pistone.
Not so much a "lie" as it is gross incompetence. Shame people fall for it :/
I think what you are missing is that SCFM is a Chinese term which stands for "So Called Feet per Minute".
So called flow monitoring
Small Chinese Farts per Month
"Fart in a wind storm" I love it, and as always thank you for the great content
Regarding the piston, lots of those have a fix piston like that, sure a pivot point could maintain a better strait-nest, but you would need a longer piston / heavier. This design seems cost effective, and good enough for this job. It moves so slightly sideways that the seal covers the crime.
Lol love your videos bro! Very thorough and entertaining!
12:13 lithium cells are good for around 1000 cycles before they drop to around 70% of their design capacity
so multiply your kwh by 10 and divide the cost by 10
@@Stefan_Kawalec that practice should be illegal
How much is a new replacement Tesla battery?
Cheaper to retrofit a gas engine after 5 years...
@@Brettjnash Tesla offers an 8 year unlimited km warranty on the model s batteries
My princess ears thank you for attenuating the compressor's audio chooch spectrum in post!
Thanks very much for doing this video. I almost got one of these but couldn't justify the cost vs a cheep plug in.
The only possible use for this would be finish carpentry. At that point there is certainly power available in the space. Cordless makes no sense.
🤔
I don't understand why this would work better in Finland?
Cold air is more dense, so you get more flow for each pump of the piston. /s
Not even though, dewalt has totally decent battery line of nail guns, they work great. This compressor is literally useless.
Even for finish work, a good cordless electric, or even better a paslode, will run circles around this thing
"Could" also be used by the guy wanting to use his impact wrench at the top of the 2000 foot antenna tower since the long air hose "might be a bit too heavy." As for me I think I will not need one. :)
Lithium balancing is done in a pretty easy way: each cell have an independantly controlled resistor in parallel with each cell. Those resistors are to discharge that particular cell. What the charger do is:
1- charge all cells in series until one cell reach 4.20V (it can't charge one cell, it can only charge all of them)
2- look for the other cells voltage. Is all cells at 4.20V? If so terminate charge.
3- Not all cells are at 4.20V, let's discharge the cell(s) at 4.20V for a bit (ex: down to 4.19V)
4- Has the timer run out? If so blink faulty pack, terminate charge. The pack spent too much time in balancing mode and is declared unbalancable, thru defective.
5- goes back to 1.
This is why there is some wires between each cells, this way it can monitor each cell voltage both at charge and discharge time.
To discharge, it just turn on a transistor (most likelly a mosfet), which then send power to the resistor. This resistor is pretty weak, as normally the pack should be quite matched, thru the unbalance is minimal, and even a few mA is more than enought to balance it within minutes.
You need to have pressure control below the gauge not above it. As you have it you've got equal pressure above and below gauge. If air were expanding unencumbered into flow meter you'd get much higher reading.
Flow in=flow out
My framing crews have been running the 60v wormdrive saws with great success.
That piston assembly looks like a Woble compressor design which have a long lasting reputation. Great review.
@@KinreeveNaku actually both. They've been building them for decades plus they have been known to runs for years at 24/7. Very expensive as well.
Not really, I have had multiple of oiled and this oil less design and assuming the motor doesn't crap out it's a 10-15 year life vs a 50 year and still going life under similar duty cycle. Or in a shop with near continuous duty about 6 months for oil less and several years for oiled.
The ultimate failure for this style is the the seal starts to wear, the piston contacts the cylinder wall, and then it scores it to hell and back leaving it putting out no pressure.
Also, in a wobble disc pump the piston does not deflect. It has a linear motion back and forth. The only wobble is of the disc attached to the the input shaft. In nearly all applications (cheap air compressors excluded) it is a detrimental problem when the piston cocks sideways in the bore.
Long story short, I tip my hat to you sir and once I can, I'll jump onto Patreon and toss a few bucks.
Wanna hear a fun story?
I live in Quebec, and my cousin Dima worked with AvE in the tech support department of Bosch, before AvE left about 3 years ago. And i was begging him for a long time to somehow set up a meeting with Him (the one whose name cannot be pronounced correctly), and my cousin was like -No man, i can't, he made me swear on my mother.
So, about a week ago, i think it was friday, my cousin Dima was fired from the tech support department of Bosch. Apparently, as a side gig, he was illegally hacking these stupid electric scooters to be able to reach 35km/h.
Long story short, he made me swear not to tell his mother that he was fired from his job, and in return he would set up a meeting. Besides, aunt Luba is an old lady, she don't need this kind of negativity in her life right now.
Anyway, Dima told me that when they worked together, every day after work, AvE visited the Old central bus station. And i was like -Yeah, cool, i know the place.
To those not familiar with the place, the "Old central bus station" is like this ugly concrete building, what they use to build in the 70's. The ones with the permanent aroma of stale pee.
As they age, these building tend to attract the kind of vendors you generally won't find in your local family friendly strip mall.
(Just as a side note, i don't judge and absolutely don't mind businesses that offer hydraulic butt toys and clamps, nor extreme vegetarian sex massages. Also, i very much like the meat and onion pirogi Vova is selling at the corner)
Where was i...
Ah yeah, so, i decided to give it a try, so me and Dima took a couple of beers and went to the bus station.
We wandered around for awhile.
The place was kindda creepy. I had no idea what we were looking for.
I sat down to roll a cigarette on a bench in front of "The Rubber Empire". Dima left standing and was nervously looking around as i was smoking the weirdly shaped cigarette i managed to produce.
The flicking neon sign stated that the rubber guys had "All the rubber you can rub" and "Open 24/7". A well built man with lush facial hair, in an elegant suit and a red turban was standing near the black door that was apparently the entrance to the place.
Suddenly i felt Dima tapping on my shoulder. He whispered -That's him. The guy with the paper bag...
I turned around.
-Him? Are you sure?
I was shocked to say the least. I always imagined AvE (real name's Colin by the way) looking like.. you know, like your average canadian asshole, i guess. But against all my expectations, in front of me stood a short bald man, wearing an expensive, three piece, pin-stripe suit. He had glasses with with thick lenses that made his eyes look small and spaced apart.
He was holding a brown paper bag in his hand and was heading towards the Empire.
I stood up, flicked the half finished cigarette, and advanced towards him to introduce myself. I called -Ave!
He spooked and turned around. I reached my hand and said -Ave, it's a great...
He stepped back and before i could finish my sentence he asked -What's your name, boy?
He sniffed his nose and touched his left nostril with his thumb a couple of times.
I said -Hey Ave! I'm Stas, it's an honor...
-Keep your dick in a vise! - he interrupted me. He looked annoyed. -What do you say about my empire of dirt, bud? - he pointed towards the Rubber Empire.
-We haven't been... - i tried answering his question, but he interrupted me again...
-That's skookum! - He blurted -Now, fuck off.
He turned away and shouted -Farouk, come take this from me.
The man with the turban approached us.
-Please call Rudolf, tell him to prepare the room - said AvE to Farouk and gave him the paper bag. He turned away and started walking towards the black door of The Empire.
-I love your channel, man! - i said to his back.
-Farouk, take care of this please - he said without turning his head and made a waving hand gesture.
-I think it would be better for all of us if both of you get the fuck out of here before i break your shit - Calmly said Farouk.
-We're sorry, sir - said Dima. He then turned to me and said -Lets get the fuck out of here, before we'd have to use our free medical care.
As we started walking, i heard him shout -Farouk, time!
The entire experience left a bad taste in my mouth, and i really had to take this off my chest. I'm thinking about unsubscribing.
My father-in-law patented (#3961I68 & #3961869] the “Wobble” compressor in 1974 while at Thomas Industries. The “Wobble” compressor has no wrist-pin and uses a teflon cup which seals the piston to the cylinder. The piston wobbles in the cylinder, hence the name. Thomas Industries also manufactured diaphragm compressors and spray guns sold under the “Sprayit” brand at Sears. Also, be advised that pressure gauges are very inaccurate at the low and high ends of the gauge. A much smaller range gauge would yield much greater accuracy. I believe you discussed this when using a dial indicator. Your pressure readings are “gobbage!”
Sorry, #3961868 & #3961869.
The “what up bloods” alone was worth it!
You got my attention when you said this will be on the final exam
Thanks for the awesome vids. 2month sub now pretty much watched em all. Lol
Please test the current when you connect two cells that are at different voltages - it would make a good video! I've tried it with lipos and it's a lot smaller than you'd think. Even a fully charged cell connected to a fully-discharged cell resulted in less than a 2c current, which dropped off within a few seconds.
should'nt be the gauge and the needlevalve be at the tank itself? Or at least before the flowmeter, because the flowmeter causes restriction and the needlevalve keeps the pressure inside the flowmeter at mains. To measure optimal flow the pressure difference should be max at the exit of the flowmeter. E.g. the MIG welder,
you get max flow if the gas is flowing freely out of the nozzle.
Regardless, you saw the flow at the end of the needle valve. When he put that rag over it it didn't even move the slightest
Contrary to Aves opinion here... this is my own personal dissent, I have owned one of these for a few years now and have nothing but great things to say about it. I am a general contractor and also live on a small homestead. This thing goes everywhere with me. I use it for everything from inflating tires to running a roofing nailer to shingle a barn. I use it for warranty work on clients houses and even framing jobs. I can trim out an entire 2,300 ft house on one 9ah battery. I have no complaints and the batteries have all held up fine. I hav me had one flexvolt battery fail in 4 years (in a faulty tool) and Dewalt replaced them both no questions asked. I own both Dewalt and Milwaukee battery tools and they are both great comparable Comercial grade tools.
Going way out on a limb; maybe they meant 1.2 CFM at atmospheric pressure? Instead of measuring your CFM in the stream of compressed air, try measuring the CFM after expansion. So the compressor is pumping out 90 psi, but your flow meter is on the low pressure side of the outlet valve, so you're measuring the flow after the air has expanded back to atmospheric pressure. I wonder if they would even be in the ballpark then?
makes sense, in my experience if a marketing twonk can find a bigger number to put on the box they will, no matter how illogical/misleading etc., which is probably where the SCFM comes from; "it my be misleading but we TOLD you how we measured it so you can't take legal action."
i bet, since the air coming out will be very cold, they are probably even putting it through a heat exchanger to warm it up and only then measuring the volume!
@@chrisedwards3866 I'll rephrase; assuming the compressor output is restricted such that it's outputting 90psi, maybe the manufacturer measured the 1.2CFM at the inlet side of the compressor, not the outlet. Going by Boyle's law and assuming the world and air are perfect, a super rough ballpark would give us 1.2 cubic feet at atmospheric pressure is only about 0.17 cubic feet at 90psi. So if the compressor is outputting 90psi air at 0.17 cfm, the inlet should read about 1.2cfm. Likewise that 0.17cfm output at 90psi would measure 1.2cfm after expansion back to atmospheric pressure. Maybe that's how they measured?
@@chrisedwards3866 scfm means cfm at standard temperature and pressure. It is 70 degrees F and atmospheric pressure at sea level. 1.2 cfm at atmospheric pressure is literally what it means.
@@simonplace5164 Scfm is normalized to 70F and atmospheric pressure at sea level (14.7 psi absolute). It is actually more accurately a mass flow measurement, not a volumetric one. Changed the temperature or pressure but flow the same mass and scfm doesn't change, only the cfm would.
Was a comment deleted, I keep getting a notification someone replied to me but there is no reply there...
What a cute little toy. I need to get one of these for my kids little workshop. About all its good for.
We have one at work its handy at times. Im a roofer and we dont allways have electric available on some repair jobs and dont allways have our gas compressor. Though i cant shingle as fast it does allow me to get the job done easier then handbanging everything. And it does run our framing gun.
99% I have no idea what ur talking about but love ur voice and videos
Glycerin in guage is a damper and a dampener if the schmoo seeps out.
That flow meter looks pretty handy
I have rebuilt many larger compressors that are of a similar design for oxygen concentrators and I actually listen for that squeak as a test if it squeaks the piston seal is good and the valves are clean.
Timing is everything. Good points made at the end. Great video. Will look elsewhere.
Love the channel ive learned so much from you
I'm not sure of this but try mounting the flow meter after the needle valve.
The spec sheets from LG and Panasonic for the 18650 cells for these batteries rate the cells at 300 charges until 70% degradation. That's based on full charge to full discharge (0 to 100%). 18650s don't like full charges and discharges since it degrades them much faster than 20% soc to 80% soc, for example. This is usually plenty for most home-gamers.
The probem with the chargers (DeWalt XR series) for these batteries, they push a *lot* of current to charge the batteries - 4 amps for the compacts and up to 8 amps for the big boys. By maxing out the charge current capacity and the discharge capacity of the cell chemistry AND charging/discharging to 0/100% soc each time is really really hard on the cells.
If you want your batteries to last way longer, pull them from the tool before they are empty and use a hobby charger to bring them .2 volts or .5 volts from full charge. Pretty crazy to have this much designed obsolescence built into a $100+ part.
It's not really planned obsolescence if it gives the consumer more run time. Charging from 20-80% would reduce that time a battery lasts in the tool before recharging by approx. the 40% you are not using. That's quite a lot.
Love your work Ave, but the flow gauge in NFG. Dive into the differences of Acfm, scfm, and icfm. ISO standardizes atm pressure, temperature and humidity for testing. Measuring is usually done with an orifice plate or venturi tubes.
Specific power is also the ratio of kw to cfm.
Great honest review!
I've been using sewing machine oil to replace the oil in the pressure gauges at my work. My life would be a lot easier if my co-workers would stop breaking them, but you do what you can.
Had this playing in the werkstatt and kept having to fight the urge to check my lines when I heard the leaky airy noises.
It's a wobble piston design, just like Thomas vacuum pump/compressors. The Thomas pumps last quite a long time. At work in a very dusty horrible environment, they last about 1-2 months running 24/7.
I'm thinking about getting one for truck tires, airing down and back up some when going off-road, take it camping with my DeWalt heater lol!
Cordless tools are virtually disposal. Still have my dads black and decker drill which is about 50 years old!
6:20 such a rare and interesting wide angle shot of the shop
I agree, the flow meter is too close to the pump. When testing the factory likely has air dryers and filters in the system as well.
DeWalt Disney don't expect these to get used by professionals, they expect them to get bought by people who throw them in a cupboard just in case they might need it someday. There are people who have to have everything that is sold by their favourite 'toy-town-tools' company, yellow and black is like a designer brand to them and they have to collect the entire set !
Building sites are swarming with fan boys who have vans full of yellow and black tools, they wear yellow and black shoes, trousers, T-shirts and tool belts.
If DW sold aftershave they'd make a fortune !
I had a needle valve exactly like that, until it disappeared a while back.
I ain't saying you stole it, but..... I had one and now you have one now that I dont!
At least you can cook your breakfast on it!
$12/kwh for those batteries, but that doesn't even include the usage cost of charging them - which I'm sure is much less efficient than straight through a cord
I’d guess 80%, but it’d also be pretty easy to test
That number is only meaningful if he corrected the 60* 4 mathematical error
When it comes to pneumatics the pumps actually do produce the pressure for the system, unlike hydraulics where pumps only produce flow. This is due to air being a compressible liquid. That was an interesting topic (and a test question) we covered in my hydraulics and pneumatics class.
I disagree. Get rid of the restriction, e.g.; open compressor outlet. Any pressure? No. Any flow? Yes.
Rocking piston compressors are common, actually. Almost all oil-free piston compressors are the rocking piston type. After a while, they do need to be rebuilt with new cup seals. You can find CZcams videos from compressor makers that show the process for replacing the cup seal. They're not for making real high pressure, nor for continuous duty.
Headgear??? I love it. AvE is a very smart but funny at the same time
Gwadges
Maybe the discrepancy in cfm is the difference between scfm rating and the actual cfm you're measuring? I imagine broadcasting from the frozen ice planet of Hoth, even in this Merry Month of May, ambient air is less than the standard room temp. Though, with colder (denser) air, I would expect a higher reading. Also, probably wouldn't account for a 50% difference.
The Dewalt cells don't have internal balancing? Pretty sure they probably have some form of controller in there that balances the cells during charging. If not the batteries would be a bit on the combustible side.
The math checks out
The battery is 3P5S in 20V mode, so at worst you'll have two cells trying to charge the third, while the BMS (i sure hope it has one) will be trying to balance the 5 groups of 3 cells. Unfortunately, it doesn't seem like most tool batteries have a BMS. I've salvaged and revived a few that got unhappy enough for the charger to complain by just balancing them and charging them with a hobby charger.
One item that I have never heard addressed on cordless tools such as the Dewalt "20 volt", and the Milwaukee 18 volt lines is the actual efficiencies of the battery chargers, and of the batteries themselves. If you measured the volt-amp-hours into the charger from the shop power, and the volt -amp-hours out of the charger into the battery, you could determine the charger efficiency. And if you measured the volt-amp-hours into the battery compared to the volt-amp-hours out of the battery till minimum voltage, you could determine the efficiency of the battery itself. The two efficiencies multiplied would be the "system power efficiency". Might be interesting to do. I would think at best the system efficiency would not exceed 80%. Greg
Charge your batteries at work. It's a 2 for 1 deal....
You got that extra plug in on the power strip below your desk, that's what that extra plug was meant for...
The De Walt battery has 15 cells inside that switch from series to parallel to provide either 60 volts or 20 volts nominal. Their balancing boards are only rated for 15 amps based on the three I've taken apart for inspection.
Where other tool manufacturers is nominal voltage of the cells (3.6 or 3.7 volts depending on cell manufacturer) on their battery packs based on the cell static voltage, De Walt uses the charged cell voltage (4.2 volts) which makes their tools appear to be more powerful.
I'd like to have seen this compressor tested prior to the AvE debauchery.
You are correct apart from the terminology, and I'm nitpicking here, other tool companies use nominal voltage, Dewalt uses fully charged voltage, a meaningless number, hence why the whole concept of nominal voltage exists in the first place. It matters not one bit what the fully charged voltage of a cell is under no load because if you use that voltage to work out the amount of wattage you will get at a given load, you are going to be very very far from the actual wattage. It's an incredibly cynical marketing ploy. And I actually like Dewalt tools.
I used one of these today. One battery lasted 8 hours, steadily nailing up 1 x 6 t&G soffit with a 16 ga nailer.
Pretty sure I've coughed harder after a pack smokes and a bottle of whiskey
Battery charging efficiency also adds entropy. Peukert Law and such also applies to charging
THIS THING IS AMAZING!!!
Ive just calculated its efficiency and you wont believe the results:
1.2 scfm at 90psi = 2.04 m^3/h at 620528 pascal => 2.04m^3/h*1h/3600s*620528 pascal =351 W of output
With an input of 4.5 A at 60v => 4.5A*60V=270W input
you have an efficiency of 351/270=130%!!!!
A MIRACLE
Thank you for the audio level control. My sleeping baby son appreciates it.
Did you remember to apply the Fudge Factor?
Isnt there some sort of charge balancing either on the pack itself or on the charger? With that many cells, it seems kinda short sighted to not be able to maintain voltages across them...a DIY lipo balancer would be a fun little project.
The big push around here for cordless tools is safety. No broken ground plugs, no cord inspections don't need to worry about GFCI pigtails. In all fairness cordless tools are pretty good these days.