Replies: 11 comments 20 replies
-
|
I haven't encountered the machine in person, but given the strong similarities with a Concept2, it will probably work, In essence ORM will work on any machine, but the amount of DIY varies to make it work. I like to be as little invasive as possible, so I like to re-use existing sensors, but several others also added their own sensors. When you want to keep the existing sensor in tact: the main question is if they copied Concept2's latest approach where the flywheel also powers the monitor (and thus the wire caries 15 Volt AC) or if it is just a small pulse like the older C2's. I use ORM on a new RowErg and it works well. What kind of connector is on the end of the pick-up wire, and can you attach a volt-meter or something to it? Once the signals are picked up, it is pretty easy to configure the software. There are a few parameters, but out of the box it should already produce metrics. People typically feel if pace presented is realistic, and change parameters based on that. We are here to help you if you run into any issues. |
Beta Was this translation helpful? Give feedback.
-
|
This is just a rebranded version of the "Generic Air Rower". Mine called Zocco Body Fit (https://zocobodyfit.ro/produs/aparat-de-vaslit-zoco-body-fit-air-rower-pliabil-ecran-lcd-eficient-si-util-negru/#). In New Zealand they call it XEBEX V2 Air Rower (https://www.megafit.hu/xebex-ar-2-air-rower-legellenallasu-evezogep-cross-trening-edzeshez-v2-consoleH). We had a discussion on it: #28). on aliexpress they call it indoor rower :) here is the link Some "manufacturers" change small things like the performance monitor and they use different sensor. but the Machine is the same. Even the flywheel should have very similar inertia. They are good machines but to have them a very similar experience like on C2 there are 3 things (in addition to the clunky things on them they call "monitors") that needs changing (in the order of importance): 1) handle, original C2 is compatible, 2) shock cord (again original C2 is compatible), seat rollers (but this is debatable on mine it was rubbery that was irritatingly unsmooth compared to C2). The one you posted has the same handle I had on mine before change.
You rollers seems to be a better one and seeming the foot strap is better. 500$ is a good price actually for these. One thing you need to check whether the reed sensors are checking the rotation of the handle sprocket with two reads or the flywheel rotation (I am 90% its the handle). The good new is that even if its the handle there is a high chance that you can just move one of the reeds facing downwards to face the flywheel and ad a magnet there: 
The cheap AliExpress copies (and mine) use the same injection mold for all kind of version so they have the sitting for reeds on the flywheel where their provided reeds fit exactly only they have chosen to measure the nothingness on the handle... :D::D (on the picture I added a hall sensor that is why there you can see 3 pair of wires). The black and white is the reed. they fit into the whole on the front. |
Beta Was this translation helpful? Give feedback.
-
|
oh man, I could've save another couple hundred bucks AND gotten a better monitor? Well, live and learn I guess. |
Beta Was this translation helpful? Give feedback.
-
These monitors looks more like a PM5, but the metrics are still worthless. None of these designers/developers make a serious effort to get the data really correct. For them, it is an afterthought. |
Beta Was this translation helpful? Give feedback.
-
So, once stuff is connected, the Generic_Air_Rower profile should work, or at least provide a good starting point. |
Beta Was this translation helpful? Give feedback.
-
This monitor is junk :) this is what mine has :):) it measures handle pulls only... it calculates the metrics solely from how many times you pull the handle :):)
More or less yes. assuming the flywheel is the same as well :D |
Beta Was this translation helpful? Give feedback.
-
|
The R50 has a 2-wire sensor with a magnet that looks hot-glued onto the flywheel (I'll probably be fixing that sooner rather than later). From my comparisons I gather the R50 is closest to Concept2's Model C. the D, E and RowErg all have the 3-wire transformer/sensor. My plan is to get a hold of a PM5 and a Model C replacement pickup to measure resistances and see what a known reading looks like. Hopefully it is exactly like the R50 sensor so I can just build a pigtail from JST SM to 2.5mm mono jack and plug that sucker into the PM5. R50 tachometer Funny thing, the monitor has 3 connections going into the support arm but only 2 exiting. One is of course the tachometer and another measures the resistance setting (I'm presuming it's a potentiometer). I'm going to practice patience and resist the urge to open up that arm to see what the heck that 3rd connection is doing. |
Beta Was this translation helpful? Give feedback.
-
Ah, that is by far the easiest approach, probably a reed switch or Hall effect sensor.
Although that might work electrically, it won't result in decent metrics. Key parameters in the PM5's software are fixed for their machines and are different for your machine (flywheel inertia and thus dragfactor, distance, pace, etc.). That is why we have a setup guide for unkown machines: you need to set essential parameters per machine.
That is weird. The flywheel will indicate dragforce during the recovery, so that might not be needed at all. But perhaps some other sensor? |
Beta Was this translation helpful? Give feedback.
-
|
@YAMLcase your best shot is bluetooth implementaton as we discussed, i just need the bluetooth name of the device :) |
Beta Was this translation helpful? Give feedback.
-
|
Implementing a bluetooth bridge will not fix that his metrics still suck. The monitors of these cheap manufacturers essentially are glorified bike computers. These monitors just produce garbage data as they don't take in account the mechanics of a rowing machine. They deliver some kind of data, but they are too stupid to translate the dynamic flywheel behaviour into meaningful rowing metrics (see this explanation). On EXR we see people rowing 10K's in sprint world records on these machines. This is actually why OpenRowingMonitor is created: to show it can be done and help people to get decent metrics out of decent hardware. Aside the quality of metrics, OpenRowingMonitor provides a fully functional PM5 BLE emulator that is tested against ErgZone, KinoMap, EXR (the Zwift for Rowing) etc.. This is much better suited for communicating all rowing metrics than FTMS is, as it communicates state-based on the rowing stroke (i.e. start of drive and recovery), which makes data much more responsive and allows EXR to sync the stroke movement to the app. |
Beta Was this translation helpful? Give feedback.
-
|
ok I wasn't aware of the "garbage" issue :) |
Beta Was this translation helpful? Give feedback.
-
Yeah, where on bikes the calculation of power is relatively simple, it is pretty tough for rowing machines (the flywheel varies a lot in speed throughout the stroke, and you need to calculate the air resistance at the exact right time). Even companies like Peleton and NordicTrack don't get it right, despite the extremely expensive hardware. |
Beta Was this translation helpful? Give feedback.
-
As Jaap said, do not try to fit a pm5 here. It will not work. The inertia is not the same as pm5 (inertia on mine is around 0.07848 while C2 is around 0.1).
Are you sure one of the 3 measures the resistance on the air resistance leaver? Its possible that the 2nd and 3rd wire is for the handle rotation detection, so they can detect whether machine is drive or recovery. This helps with their thing to calculate metrics better. Though looking at the picture, there does not seem to be sensor on the handle sprocket so it is not likely. Any way, converting this machine to ORM is as simple as it gets:
Generic Air Rower profile is calibrated for one magnet exactly so it should work out of the box. |
Beta Was this translation helpful? Give feedback.
-
|
Ok, curiosity got the best of me and I'm glad it did... what the heck is this thing? It was just kinda jammed in the middle of the arm. I see no model/brand markings, only component labels. the back is blank. grok identified it as a microphone, but this doesn't seem likely unless the lizard people are spying on me lol. 
|
Beta Was this translation helpful? Give feedback.
-
|
The wires are labeled: 3V, GND, and OUT. This suggests it is a powered component, and that it will generate some signal. Weird place to insert it, unless you want it out of the monitor for some reason. |
Beta Was this translation helpful? Give feedback.
-
|
I vote for lizard people :):) Honestly they made a good job so no-one can see what this is. the flat is probably some kind of IC. I would even go as far as an MCU considering the 3.3v that is standard for these. The big black thing I though its a electrolyte capacitor but slikscreen A1 and A2 is unconventional marking and the shape is a bit strange. Not to mention that for a microcontroller you dont need such a huge capacitor. What you can try is what happens if you dont plug this in and run the monitor (I wonder if this is the BLE module and may be they have an NRF chip there. This does not expalin the big component (may be an antenna??? unlikely. also the one output wire is a bit shy for data for such device and even if that it is But to be fair this is not necessary for ORM to work. (honestly I am really intrigued by this design and I hope you decide to find out what it is because it is very interesting :)) Just a quick question. are you sure that one wire goes to the resistance leaver? Because that means that their drag factor is fixed numbers are in a lookup table, but at least they measure the flywheel rotation. |
Beta Was this translation helpful? Give feedback.
-
|
it says: "can also take my HR from my Garmin watch." My best bet is that this is infact bluetooth and for connecting to a HR. big chunky thing can be antenna (explains |
Beta Was this translation helpful? Give feedback.
-
|
Just to wrap up some of the findings in this thread: that mystery device in the arm is most likely the HRM sensor. I spent a bit of time researching, crowdsourcing on reddit and asking grok with no conclusive answer but HRM sensor is most likely. definitely not an off-the-shelf part . I don't have a Polar or Garmin to test it out so... for me this quells my curiosity. the reed sensor pickup on the R50 won't work with the PM5: different kind of sensor is needed. I got the Model C pickup, tore it apart and found that it was a coil. it appears the PM5 measures the magnetic field, not resistance. The flywheel won't work with the Model C pickup. I got no measurements when I just swapped the pickups. looking more into it I found that the concept2 flywheel has a completely different configuration for the magnets. there are 3 magnets evenly spaced and this just seemed too much trouble to try and figure out how to get working. I ran across a reddit thread where someone had successfully made a retrofit by purchasing a Model D/E pickup, axel, flywheel... well of course why not just get the Concept 2 at that point. |
Beta Was this translation helpful? Give feedback.
-
|
Thanks for the HR thing, I think that is the most logical answer. Just to complete your research on the way the different C2 pickups: PM3: it uses resistance to measure the magnet. Basically it has a coil that when the magnet passes changes its resistance, which changes the voltage and this change is measured (via an amplifyer of course) by the PM (https://c2forum.com/viewtopic.php?f=10&t=207567). So here the magnet size is also important as the resistance change is dependent on the amount of magnetic force (this could mean that if you have too big magnet it will not work though this would depend on the amplifier and the comparator inside the circuit of the monitor). PM5: it has a power generator cicuit (hence it has 12 magnet with alternating direction south/north which when rotating generates power in a coil) and has 3 sleeves. one is ground, one is the power "charger" that generates power for the PM so the battery can last longer when you row, and 3rd is the signal which is relatively high voltages (I measured 18-20v) in a sinoid wave. (https://c2forum.com/viewtopic.php?f=10&t=207567) Also as a side note, my copy rower flywheel inertia is around 0.078 while the C2 is around 0.1 ish. Since the PMs bake their values in they will not work relyably with other flywheel. Actually PM5 can change the erg type (https://www.youtube.com/watch?v=hcqCwNniArI) because it is retrofitable to almost any model (even Model B and based on their web site Model A too?). In such case I suspect it loads the constants (number of impulses and all that) and also "switchis" to the right signal detection mode. |
Beta Was this translation helpful? Give feedback.
-
|
Bringing this conversation up as I am a new r50 owner and am very interested in getting ORM working, particularly the ANT+ -> Garmin component. Exciting! This comment inspired hope:
"out of the box" specifically was really exciting. I've got a pi3 laying around, I think. And an ANT dongle. Update: Read the docs! Ordered more Dupont Cables than I will ever need in this lifetime! Also @Abasz :
I haven't popped the thing open myself, but all evidence points to "yes" — the manual has a section dedicated to calibrating the resistance lever arm, and some light teardowns on youtube show the cable running to the lever. Is… is that a helpful sensor to have for ORM? or just like "hey, at least they tried!" also, btw @JaapvanEkris IRT:
I think these guys are blatantly cheating (putting a towel over the fan). In my and I think most reviewers' experience, this thing undercuts you a fair amount. Some sources: |
Beta Was this translation helpful? Give feedback.
-
Welcome. We'll get it to work, no worries.
Know that feeling. I got a whole bunch of them as well :)
It is somewhere between "hey, at least they tried!", "how stupid can you get" and "Why not complete what you are doing?". Drag (the actual resistance, not the lever) can change due to dust collection, air pressure, etc.. So knowing where the lever is might be helpfull, but to real accurate stuff, you need to measure how the flywheel behaves in a session. The key math is actually pretty straightforward. It becomes complex if you want it to be precise and robust. The added complexity of a sensor and calibration procedure is probably more work than get the math right.
There are some machines who just report insane power production. Even the WaterRower is 10% too optimistic, but other machines are much much worse. I know the brands, I've tested them. It is just that the engineers got the job to "produce numbers", instead of "produce credible metrics".
Thanks. |
Beta Was this translation helpful? Give feedback.
-
|
Hello everyone first of all I want to thanks for such great project. Merach R50 it´s not same like other chinese copies of concept row machine you follow. I read lot of tests and deffietively decide to buy this Merach r50 than Concept row erg. Only originál display is not good readable and not show correct values. |
Beta Was this translation helpful? Give feedback.
-
Good to hear! Would you be willing to share your entire config and the raw recording of 20 or more srrokes? This way I can include it in the standard configurations, and keep it consistent when there are changes to the engine. |
Beta Was this translation helpful? Give feedback.
-
|
Yes i will send it to you. |
Beta Was this translation helpful? Give feedback.
-
|
@Skodavrs007 did you hardwire a USB battery into the 5V inputs on the board? Looks neat! I have been thinking about how I might be able to keep my machine free from wall outlets |
Beta Was this translation helpful? Give feedback.
-
I use this hat with regulator its safe solution. https://shop.pimoroni.com/products/wide-input-shim?variant=2168104321034 Its still not finished it means final back cover will have switch connected to this hat to cut off battery. I will share photos when will be finished. |
Beta Was this translation helpful? Give feedback.
-
|
@Skodavrs007 your setup looks awesome. i recently got an R50 myself and im about to set it up with ORM. Also i hope you didnt have to make any other hardware updates on the rower itself as i do not feel very comfortable with that part :) thanks guys for this awesome project @JaapvanEkris and friends! |
Beta Was this translation helpful? Give feedback.
-
1.3 radius is ok for me now but you much check if ‘drive’ correspont with reality if not you must change it. I also want to test hall sensor with more magnets thats why I use 5x3mm magnet now is only one instaled in 3D printed base |
Beta Was this translation helpful? Give feedback.
-
|
@Skodavrs007 thanks sorry for my rookie questions here but how would i check if the |
Beta Was this translation helpful? Give feedback.
-
|
You dont need to disassemble anything. Set 1.3 and check value on screen drive lenght during the Rowingdata. Than check real lengh on chain. Easiest way to check it is to mark on chain by tape starting point of your row phase and with second person measure chain lengh if you are in the end of rowing phase.
|
Beta Was this translation helpful? Give feedback.
-
|
awesome thank you!! |
Beta Was this translation helpful? Give feedback.
Uh oh!
There was an error while loading. Please reload this page.
-
Has anyone had success replacing the useless monitor on a Merach R50? I'm looking to build an ORM for this but wanted to check with others first on their experiences.
Beta Was this translation helpful? Give feedback.
All reactions