USA warehouse now open. Our USA warehouse is now open! Low cost shipping and an ever growing variety make ordering from the US warehouse even better value!
Item found in the following categories;
> Tools
> Measuring
RATED:
HobbyKing Rpm/KV Reader
The HobbyKing Rpm/KV Reader is a quick and easy way to test the KV rating of your motor.
Specs: Voltage: 7~25v RPM Range: 0~99,999 Auto save for last test result Backlit LCD
Hi, can I use it during the flight of my heli, to record the max readout about rpm/v/kv?
Is it possible to utilize it with 6s ( 25,2) battery?
If I want to know the rpms of my heli in flight, is it sufficient utilize it or have I to use an optical tachometer ( or both )?
Thank you for your attention
Can anyone direct me to an article that tells you what to do with the Kv value.
What I think is most important is never provided.
2 cells 3 cells
Max current for 15 seconds
Max current continuous (in the air)
Is there anyone who thinks Kv is more important than that?
A question re the yellow wire .... Does the clip simply go around the insulation of one of the motor wires or does it have to have direct contact with the bare wire?
Beware, the picture shows what you would assume to be 2 pairs of positive and negative wires coming out where you could solder on your choice of connectors but mine came with the xt connectors soldered right on the pcb. A big issue since I use deans connectors.
I emailed HK about this and told them they needed to change their picture and they didn't seem to give a ****. Get your stuff together HK.
Other than that it works good.
First, if it is cost effective, return the product. Otherwise check for a "dry" joint in the soldering where the connectors for the battery and output are soldered onto the PC-Board. The sign of a bad joint is that usually it is not shinny but dull/mat.
1) Will this item burn if i pass 120 Amps throw it? heheh. Or its better to buy "Hobby King K1 RPM-KV meter for BL motors" for the test? 2) What for it stays between ESC and battery, does it measure amps/watts?
amperage that will get you no matter. This device works only with 12 volt batteries (3s). I agree with you when he said getting in between the esc and the battery would measure amps. which has only one wire should be connected in one of the three motor wires, either. well it measures the electrical pulse through the wire by calculating the rpm / kv
It will show all data which i described above despite with or without prop. You can put it on or leave it off, its up to you, kV reader will be showing what is going on at that exact moment you are doing the test.
You will not get a proper Kv reading if you have a load (prop) on the motor. Kv is measured without load. If you want to know how fast your prop is spinning, it will show you that, but the presented Kv value with a prop mounted is not true.
ive just used mine and when i hit full throttle on my radio the device screen actaully shows the motor dropping rpm and kv? shouldnt it be showing the max performance of the brushless motor
The Kv rating has nothing to do with max power.A 1000Kv motor rotates 1000times for every volt that is applied but w/o a prop or load on it. If you put a prop or prop adapter is going to change the Kv rate. If you prop it,then you can use the RPM to calclate max thrust at WOT.
you dont get what i mean, when i use the device i slowly pull the throttle back and watch the rpm/kv rise. but as soon as i pass half throttle and almost hit full it starts to drop off and it gives me a reading know where near close to what the motor is rated, and this is when unloaded.
You do have to factor in the # of poles your motor has. Try this link,it's another Kv/RPM meter from HK but they should read the same way. www.link Hope this helps.
No, it will not. This tool just tells you voltage, Kv, RPM and max Kv achived. In order to make a dissision, what prop you should use, you must have at least a wattmeter more to check the Amp consuption. Then you will be able to make a good desission about a prop. Regards
Does it tell RPM with or without a prop on motor? Kv is measured in a no load setting. For it to give a prop RPM reading,it must be able to read with a load. Does it have two modes,one for Kv and one for RPM?
Sameone knows if this kv-tester also work with brushed-motors or just brushless only?
Tanks in advance.
Qualcuno s se questo kv-tester funziona anche con i motori a spazzola, o solo con i brushless?
Grazie.
Me again !
I'm actually building a DH-88 comet, and main the problem with a twin engine air plane is when the two engine don't turn at the same speed... usually it's very bad for the plane... And I really want to put all the chance I can on my side (mettre toute les chance de mon cote in French).
So will you use this tool or a tachometer to make sure both engine rotate at the same speed ?
Si, con questo kv-tester (rpm/volt-tester) puoi scegliere una coppia di motori che abbia lo stesso regime di giri (rpm/volt), a parit di tensione applicata.
Yes, with this kv-tester (rpm/volt-tester) you can make a choice for the best twin electric-motors (with same rpm/volt, at same volts value you supply either electric motors).
one problem might be the motors are at different speed but the worst is that one motor sometimes start to drop off during flight
be on guard . IT happened to me after 3 years of no trouble?
Nose down,cut power,land ( just a friendly suggestion)
They do make a prop sync device that will allow you to keep your second motor with the first. You can turn it on and off remotely, that way if #1 fails, #2 won't follow. I have several twins and 1 4 engine, and have never had a problem. There is no way to keep the props exactly together without some extra electronics to monitor and control the rpm of the motor. This device used as preventative maintenance will let you know when a motor is getting weaker.
it measures voltage, amperage, rpm and calculates kv from these parameters like motocalc do. i have very same thing from original manufacturer and it lies as hell. probably due to low precision of the voltage measurement.
Actually it does not measure amperage *)
It just measures time between voltage appears on the selected wire. The faster the ESC cycles phases, the faster the voltage on selected wire will appear. You can easily measure KV with that, providing you know the number of poles in the motor. You cannot actually measure RPM with, because it is depended on the voltage of your pack (which changes, due to load, battery stress, etc...)
Once you put it in line wiht the ESC, then you simply connect the alligator clip to one of the 3 motor wires. I am personnally going to use a "T" pin (available at walmart in the crafts department and they are cheap). Pierce the wire, follow the directions to set the polls and take the readings. Very simple.
It is for electrics but i doubt it can measure headpseed since the final spin goes through a gear ration. It's just for maximum RPM with or without load along with the true kv Rating of the motor. I don't know how accurate this device is though.
KV is a term which is specific to electric motors - it's the constant number of RPM per input volt.
ie. a 3000KV motor will turn at 3000 RPM per volt. At 10V it would spin at 30,000 RPM.
To try and resolve the confusion here, this is NOT a TACH. It is NOT for measuring ROM like some think it does. It is for measuring Kv of an electric motor. It will not work for measuring your prop RPM, or your rotor speed on your heli.
Just got mine. It has XT60 plugs instead of the naked pigtails in the picture. I bought one a year ago, and that came with the pigtails, no XT60 plugs. For me it means I have to build som extension cords with XT60 plugs before I can use it. The male/female XT60 plugs is BK here at Hobbyking. A big disapointment HK ! The product in the picture is what I order, not a "close to the picture" product. Shape up HK !
It is a nice little tool to measure the rpm. Unfortunately it is equipped with XT60 connectors and not with T- connectors. You have to order also adapters for your plugs.
2 comments. Reply..
Overall Rating
dpowellmeii
5 likes
Value
Quality
Like it?
Beware, the picture shows what you would assume to be 2 pairs of positive and negative wires coming out where you could solder on your choice of connectors but mine came with the xt connectors soldered right on the pcb. A big issue since I use deans connectors.
I emailed HK about this and told them they needed to change their picture and they didn't seem to give a crap. Get your stuff together HK.
Other than that it works good. Beware, the picture shows what you would assume to be 2 pairs of positive and negative wires coming out where you could solder on your choice of connectors but mine came with the xt connectors soldered right on the pcb. A big issue since I use deans connectors.
I emailed HK about this and told them they needed to change their picture and they didn't seem to give a crap. Get your stuff together HK.
Other than that it works good.
No comments. Reply..
Overall Rating
slopenut
6 likes
Value
Quality
Like it?
checked this tach against a high end calibrated tach where i work
used a Turnigy 1100 kv mtr running on 12V
the calibrated tach showed 13k revs at no load
correct 12V x 1100Kv= 13200revs
hobby king tach showed just over 14k revs at no load
a 10pcnt variation
take it for what it is.
cheers
g
No comments. Reply..
Overall Rating
wensor
8 likes
Value
UNRATED
Quality
UNRATED
Like it?
translated
-
i thought that was gonna give a lot of use but the first day i had it i've become profitable. very easy to use and comfortable, has screen lit even if a bit small characters you. discovered that an engine that was giving me problems, a turnigy 2836-1000kv 1300kv was actually a lap and spent the folding prop was wearing it.
Copyright 2012 Hextronik Limited.
The HobbyKing.com®, OrangeRx, Turnigy, Durafly, nano-tech and other brand logos and names are trademarks of hexTronik Limited.
All rights reserved
.jpg)
