Configuring a home-built rower #80

roblloyd319 · 2022-08-23T15:47:14Z

roblloyd319
Aug 23, 2022

So, I built my own rower last winter and never really used it much since I started bike training season just as I finished it up. It's time to put it to use, and get it connected to EXR/Strava. It's a bit of a unique setup in that I used a bike wheel (and chain drive, and 8 speeds to choose from) with a bike fluid trainer providing the resistance.

I got the Rowing Monitor setup and running; I can access it thru a browser, and it connects to EXR no problem. Next step is getting it setup for my rower. I plan to run thru the basic setup first. But, I was reading the more advanced setup. With this rower setup, I have no idea how to calculate the inertia. Since the inertia is not just the bike wheel, but also the flywheel of the training stand (not to mention the fluid resistance and friction of the tire against the roller). So, I think that option would have to go by trial and error.

But, I saw a mention in the config file of 'power curves'. I couldn't find another reference to this in any of the docs. But, it sounds like it might work for my rower, if it's what I think it is. The fluid training stand (Kurt Kinetic) has a known power vs. speed characteristic. So, it should be possible to simply lookup the power once you calculate the wheel speed. Is this a function currently in open rowing monitor?

roblloyd319 · 2022-08-23T15:54:48Z

roblloyd319
Aug 23, 2022
Author

Sorry, not power curves, force curves. Maybe it's not what I think it is...

0 replies

JaapvanEkris · 2022-08-24T08:12:23Z

JaapvanEkris
Aug 24, 2022

Hi Rob,

That is so cool! Please share pictures because that sounds like a very interesting machine.

The way forward definitely is the "trial and error" approach. Most people are hesitant to take apart their rower, so most people guess their inertia.

When in rowing we talk about Power/Force Curves, we talk about an in-stroke power/force curve. This depicts the power/force in relation to the position in the drive. For an example, you can look here: https://rowsandall.com/rowers/workout/0587489a/. This way you can see where power/force dips, and typically a transition isn't optimal. I currently am developing the newer Rowing Engine (see https://github.com/JaapvanEkris/openrowingmonitor/tree/Sandbox) that provides that functionality and I'm testing it on the known rowers. Some rowers deliver more useable results than others, where the big factor seems to be the number of impulses per stroke.

Power curves and Force curves are closely related (when you look at my example, you can see that Open Rowing Monitor provides both). I developed them both and while both have their own use, they highlight the same issues. So I confuse them all the time as well :)

I hope you found this document: https://github.com/laberning/openrowingmonitor/blob/main/docs/rower_settings.md that is aimed to help you get the right settings. I think the best approach is to first get your ranges of the impulses right: what is the minimum and maximum impulse time? After that, you need stroke detection to work reliable. If you can detect strokes reliable, than you can look at the power or speed. In rowing they are linked through a constant (Power is the 2.8 * cube of the linear velocity), so getting one of the two right suffices. I baselined my NordicTrack by comparing my effort to a known rower in the gym (Concept2 Model D with a PM3). I know what my speeds usually are, and thus what to expect on the NordicTrack.

0 replies

roblloyd319 · 2022-08-24T12:22:23Z

roblloyd319
Aug 24, 2022
Author

Pics as requested...

[img]https://live.staticflickr.com/65535/51841730400_789f39c5bc_c.jpg[/img]
[img]https://live.staticflickr.com/65535/51840994626_a21c489771_c.jpg[/img]
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[img]https://live.staticflickr.com/65535/51841353604_d701becbaf_c.jpg[/img]
[img]https://live.staticflickr.com/65535/51841112203_55b07a642a_c.jpg[/img]

Training stand isn't installed in these pics, but it clamps onto the axle skewer the same as it does on a bike.

I installed 4 magnets on the spokes and clipped a reed switch off an old speed sensor. I edited the config file for 4 impulses per revolution. I'll get the switch hooked up tonight and try to get some data from the thing. See if I can figure out the other parameters.

I'd still like to think of a way to calculate the power using the known speed/load characteristic of the trainer. At least as a comparison to the engine's calculation. Maybe even do it as a check outside the rowing engine (a lookup in excel for example).

One more thing - the wheel I used for this machine has a PowerTap G3 hub. The original idea was to use that (long before I found this engine) and in fact I used it to row a bike in Zwift several times last winter. Of course, it doesn't work quite right. 'Cadence' has almost no meaning, though it seemed close to half of my stroke rate. And, the power is not continuous as it would be on a bike, so, the avatar in Zwift would pedal hard, then coast, etc.

Here's an example in Strava - https://www.strava.com/activities/6571468894/analysis

3 replies

JaapvanEkris Aug 24, 2022

Pics as requested...

That looks pretty cool with that wood. It also resembles a Concept2 Model A a bit (see https://www.concept2.nl/nl/service/indoor-rowers/model-a). They used these small plastic plates to generate drag. Might be an alternative solution for you.

I installed 4 magnets on the spokes and clipped a reed switch off an old speed sensor. I edited the config file for 4 impulses per revolution. I'll get the switch hooked up tonight and try to get some data from the thing. See if I can figure out the other parameters.

That is usually the approach. In the pics I recognize you can shift gears. I have no clue what that will do with the metrics.

I'd still like to think of a way to calculate the power using the known speed/load characteristic of the trainer. At least as a comparison to the engine's calculation. Maybe even do it as a check outside the rowing engine (a lookup in excel for example).

That could be an idea indeed. In theory they should result in the same data. Either you change the drag (when the automatic calculation of drag is disabled) or you change the flywheel inertia in such a way that the power matches. Please note that in rowing we do calculate work (and thus power) differently: in rowing we only calculate power during the drive, and not in the recovery. That is something that seems to be present in the Strava data you shared as well: power fluctuates between 200 and 50 watts (we display the power across the stroke, so the work during the drive divided by the time of the total stroke).

One more thing - the wheel I used for this machine has a PowerTap G3 hub. The original idea was to use that (long before I found this engine) and in fact I used it to row a bike in Zwift several times last winter. Of course, it doesn't work quite right. 'Cadence' has almost no meaning, though it seemed close to half of my stroke rate. And, the power is not continuous as it would be on a bike, so, the avatar in Zwift would pedal hard, then coast, etc.

Yep, that is the typical difference between cycling and rowing. On a bike you have a constant power where the leg that produces it alternates. In rowing, we have a "Drive" phase where both legs produce power (followed by a back and arms section), and then a "Recovery" section where we just casually slide down to get ready for the next stroke. In terms of rowing, during the recovery energy isn't produced, only lost due to drag (this is the trick we use to measure the drag of the flywheel), and during the drive we increase the speed again. So when looking at metrics for rowing, we provide them across the stroke (this is actually what everybody does). So when we talk about "power", we actually talk about "the average power across the stroke, including recovery".

The newer engine I'm developing can calculate instant power (similar to your bike flywheel) and there you see that the average more or less matches the average per stroke, but the instant power fluctuates much more. That fluctuation is important to us, as it provides clues about the smooth transition between the leg-drive to the back and arms (see https://www.concept2.com/indoor-rowers/training/tips-and-general-info/using-the-force-curve).

Here's an example in Strava - https://www.concept2.com/indoor-rowers/training/tips-and-general-info/using-the-force-curve

Looks familiar :). Please note that rowing speeds typically are around 12 to 15 km/h (i.e. 2:00 to 2:30 per 500 meters).

roblloyd319 Aug 24, 2022
Author

That could be an idea indeed. In theory they should result in the same data. Either you change the drag (when the automatic calculation of drag is disabled) or you change the flywheel inertia in such a way that the power matches. Please note that in rowing we do calculate work (and thus power) differently: in rowing we only calculate power during the drive, and not in the recovery.

Right, I'd have to also look at when the engine thinks it's in a power stroke, and only compare the lookup power in those times. I could then use that data to tweak the inertia (and other settings) to get the engine closer.

In the pics I recognize you can shift gears. I have no clue what that will do with the metrics.

Yeah, I did that to allow me to adjust the load on the wheel. I wasn't 100% sure I had setup the drive ratios correctly and didn't want to have something to hard to pull. In reality, it's fine in top gear; and changing the gear shouldn't be necessary. I want to keep the fluid resistance - it's much quieter than a fan. Actually, the noisiest part of my rower is the skate wheels occasionally squeaking (slightly) along the aluminum tracks. That and the bike freewheel pawls clicking on recovery. I might look for a quieter freewheel assembly.

Looks familiar :). Please note that rowing speeds typically are around 12 to 15 km/h (i.e. 2:00 to 2:30 per 500 meters).

Yeah, Zwift uses their own model to convert the power produced into the speed of the virtual bike. That model isn't going to give me data remotely close to an actual rowing experience. I actually don't really like rowing a bike in Zwift. It's weird. I just wanted a way to record the sessions. If it's not in Strava, it didn't happen, right? EXR will be much better if I can get my rower to work with it fairly accurately.

JaapvanEkris Aug 24, 2022

Yeah, Zwift uses their own model to convert the power produced into the speed of the virtual bike. That model isn't going to give me data remotely close to an actual rowing experience. I actually don't really like rowing a bike in Zwift. It's weird. I just wanted a way to record the sessions. If it's not in Strava, it didn't happen, right? EXR will be much better if I can get my rower to work with it fairly accurately.

Lars added the functionality to upload from Open Rowing Monitor to Strava directly a couple of months ago. I haven't tested it myself, but knowing Lars, it will work well. Otherwise there is a tcx-file, which you can upload directly to Strava. Alternative is to upload it to RowsAndAll.com, which also allows more detailed rowing analysis. In the version I'm working on it produces a csv-file with much more detailed statistics that can be processed by RowsAndAll as well. RowsAndAll can also upload to Strava.

Looking beyond the stroke metrics, EXR is one of the most interesting ones indeed. For me, it is a welcome distraction on the rower :). EXR works well with Open Rowing Monitor, both in PM5 (i.e. we mimic a Concept2 RowErg's BLE) or in FTMS mode. In PM5 mode EXR typically will disconnect once after a minute or so, and after reconnecting it will just work. FTMS works good without any issue. I use it on almost a daily basis, without much trouble. From EXR you can upload to Strava and in PM5 mode, even to Concept2.

roblloyd319 · 2022-08-25T01:42:37Z

roblloyd319
Aug 25, 2022
Author

Sample of the data I'm getting:

Aug 24 21:35:29 rowingmonitor npm[686]: stroke: 1, dur: 0.00s, power: 21w, split: 04:14, ratio: 0.14, dist: 6.0m, cal: 0.0kcal, SPM: 13.6, speed: 7.07km/h, cal/hou>
Aug 24 21:35:36 rowingmonitor npm[686]: stroke: 2, dur: 10.73s, power: 8w, split: 06:08, ratio: 0.69, dist: 16.3m, cal: 1.1kcal, SPM: 7.2, speed: 4.88km/h, cal/hou>
Aug 24 21:35:40 rowingmonitor npm[686]: stroke: 3, dur: 3.75s, power: 36w, split: 03:42, ratio: 0.66, dist: 26.0m, cal: 1.5kcal, SPM: 12.4, speed: 8.08km/h, cal/ho>
Aug 24 21:35:42 rowingmonitor npm[686]: stroke: 4, dur: 1.90s, power: 47w, split: 03:17, ratio: 0.38, dist: 30.7m, cal: 1.7kcal, SPM: 23.6, speed: 9.10km/h, cal/ho>
Aug 24 21:35:44 rowingmonitor npm[686]: stroke: 5, dur: 1.87s, power: 44w, split: 03:19, ratio: 0.33, dist: 35.5m, cal: 1.9kcal, SPM: 30.1, speed: 9.03km/h, cal/ho>
Aug 24 21:35:46 rowingmonitor npm[686]: stroke: 6, dur: 2.19s, power: 41w, split: 03:24, ratio: 0.38, dist: 40.7m, cal: 2.2kcal, SPM: 28.6, speed: 8.80km/h, cal/ho>
Aug 24 21:35:48 rowingmonitor npm[686]: stroke: 7, dur: 1.73s, power: 46w, split: 03:17, ratio: 0.27, dist: 45.9m, cal: 2.4kcal, SPM: 30.5, speed: 9.12km/h, cal/ho>
Aug 24 21:35:52 rowingmonitor npm[686]: stroke: 8, dur: 3.81s, power: 44w, split: 03:19, ratio: 0.53, dist: 54.9m, cal: 2.9kcal, SPM: 18.4, speed: 9.04km/h, cal/ho>
Aug 24 21:35:54 rowingmonitor npm[686]: stroke: 9, dur: 2.08s, power: 38w, split: 03:30, ratio: 0.41, dist: 59.4m, cal: 3.1kcal, SPM: 25.8, speed: 8.56km/h, cal/ho>
Aug 24 21:35:55 rowingmonitor npm[686]: stroke: 10, dur: 1.72s, power: 43w, split: 03:21, ratio: 0.31, dist: 63.7m, cal: 3.3kcal, SPM: 32.4, speed: 8.91km/h, cal/h>
Aug 24 21:35:59 rowingmonitor npm[686]: stroke: 11, dur: 3.80s, power: 44w, split: 03:20, ratio: 0.59, dist: 73.4m, cal: 3.8kcal, SPM: 18.0, speed: 8.99km/h, cal/h>
Aug 24 21:36:01 rowingmonitor npm[686]: stroke: 12, dur: 1.73s, power: 49w, split: 03:12, ratio: 0.35, dist: 78.2m, cal: 4.0kcal, SPM: 27.4, speed: 9.37km/h, cal/h>
Aug 24 21:36:05 rowingmonitor npm[686]: stroke: 13, dur: 3.82s, power: 42w, split: 03:22, ratio: 0.58, dist: 87.3m, cal: 4.5kcal, SPM: 17.6, speed: 8.88km/h, cal/h>
Aug 24 21:36:07 rowingmonitor npm[686]: stroke: 14, dur: 1.82s, power: 48w, split: 03:14, ratio: 0.35, dist: 92.2m, cal: 4.8kcal, SPM: 27.0, speed: 9.27km/h, cal/h>
Aug 24 21:36:08 rowingmonitor npm[686]: stroke: 15, dur: 1.88s, power: 63w, split: 02:57, ratio: 0.30, dist: 97.5m, cal: 5.0kcal, SPM: 31.1, speed: 10.12km/h, cal/>
Aug 24 21:36:21 rowingmonitor npm[686]: saving session as tcx file data/recordings/2022/08/2022-08-25_01-35-26_rowing.tcx...
Aug 24 21:36:22 rowingmonitor npm[686]: stroke: 16, dur: 3.83s, power: 16w, split: 04:37, ratio: 0.20, dist: 119.9m, cal: 5.5kcal, SPM: 0.0, speed: 6.49km/h, cal/h>
Aug 24 21:36:27 rowingmonitor npm[686]: saving session as tcx file data/recordings/2022/08/2022-08-25_01-35-26_rowing.tcx...

I counted (manually) 20 strokes for this test. The engine missed 4 of them. So, it seems to me the first step is fixing the stoke detection. How do I figure out where it's missing from this data?

18 replies

JaapvanEkris Sep 4, 2022

The power and speed do seem to match: for a 2:30 you need about 100W, for 2:00 about 200W. I'm still a bit puzzeled by your strokes per minute: 32 SPM is a typical race pace, not a training pace. Looking at these numbers, you are too quick in your recovery.

Changing the power (and thus speed) is done through the flywheel inertia for a calculated drag factor. Please look at drag settings, something is holding back a calculated drag factor.

roblloyd319 Sep 4, 2022
Author

I think the flywheel on the bike trainer is too heavy. It holds too much rpm from stroke to stroke. So, there's not enough effort after the first pull or 2. I need to find a lighter flywheel (or head over to my brother-in-laws and borrow his lathe).

JaapvanEkris Sep 4, 2022

Or more air resistance by adding flaps, scooping air, resulting in more drag.

roblloyd319 Sep 4, 2022
Author

So, I removed the flywheel (on the fluid trainer) completely just to see what it would give me.

2 things:

It loses a lot more speed on recovery this way. 20rad/s instead of 10.
The average speed of the system is lower. Bike fluid trainers have a load curve that roughly exponentially increases with speed. Without a flywheel, the average speed is lower.

So, I think a lighter flywheel is probably in order, but maybe half of the 12kg flywheel would be OK (instead of 0). But, I also need to change the drive ratio so that the wheel speed is higher overall (to increase the effort). Basically the same as you posted - increase the resistance. I think I need a smaller belt pulley.

roblloyd319 Sep 4, 2022
Author

Actually, it will be easier to change the front chain sprocket to a larger one.

roblloyd319 · 2022-08-25T03:31:51Z

roblloyd319
Aug 25, 2022
Author

Getting closer. Stroke count is really close. Though, it seems to count 1-2 strokes after I stop and the flywheel is spinning down. I don't understand that. But, maybe it's not a big deal.

Still working on the power + split times. I think it's close, but I don't have any experience on a C2 to use as a reference. I'll have to tag along with my wife to the gym and try one out to see how my rower compares. Honestly, these figures still seem a bit high to me.

Aug 24 23:26:56 rowingmonitor npm[701]: stroke: 1, dur: 0.00s, power: 142w, split: 02:15, ratio: 0.41, dist: 4.6m, cal: 0.0kcal, SPM: 30.4, speed: 13.33km/h, cal/h>
Aug 24 23:27:06 rowingmonitor npm[701]: stroke: 1, dur: 0.00s, power: 154w, split: 02:11, ratio: 0.42, dist: 4.6m, cal: 0.0kcal, SPM: 31.2, speed: 13.69km/h, cal/h>
Aug 24 23:27:10 rowingmonitor npm[701]: stroke: 2, dur: 4.88s, power: 91w, split: 02:37, ratio: 0.74, dist: 18.7m, cal: 1.1kcal, SPM: 13.8, speed: 11.39km/h, cal/h>
Aug 24 23:27:12 rowingmonitor npm[701]: stroke: 3, dur: 1.68s, power: 114w, split: 02:25, ratio: 0.51, dist: 24.7m, cal: 1.4kcal, SPM: 26.1, speed: 12.34km/h, cal/>
Aug 24 23:27:14 rowingmonitor npm[701]: stroke: 4, dur: 1.49s, power: 187w, split: 02:05, ratio: 0.39, dist: 31.3m, cal: 1.7kcal, SPM: 35.8, speed: 14.37km/h, cal/>
Aug 24 23:27:16 rowingmonitor npm[701]: stroke: 5, dur: 1.95s, power: 183w, split: 02:04, ratio: 0.45, dist: 39.6m, cal: 2.2kcal, SPM: 30.5, speed: 14.41km/h, cal/>
Aug 24 23:27:17 rowingmonitor npm[701]: stroke: 6, dur: 1.71s, power: 144w, split: 02:14, ratio: 0.37, dist: 44.8m, cal: 2.6kcal, SPM: 36.4, speed: 13.34km/h, cal/>
Aug 24 23:27:19 rowingmonitor npm[701]: stroke: 7, dur: 1.69s, power: 130w, split: 02:19, ratio: 0.43, dist: 50.8m, cal: 3.0kcal, SPM: 35.6, speed: 12.93km/h, cal/>
Aug 24 23:27:21 rowingmonitor npm[701]: stroke: 8, dur: 1.69s, power: 121w, split: 02:22, ratio: 0.43, dist: 56.7m, cal: 3.4kcal, SPM: 35.6, speed: 12.62km/h, cal/>
Aug 24 23:27:22 rowingmonitor npm[701]: stroke: 9, dur: 1.70s, power: 113w, split: 02:25, ratio: 0.44, dist: 62.6m, cal: 3.7kcal, SPM: 35.4, speed: 12.36km/h, cal/>
Aug 24 23:27:24 rowingmonitor npm[701]: stroke: 10, dur: 1.63s, power: 123w, split: 02:21, ratio: 0.41, dist: 68.7m, cal: 4.0kcal, SPM: 35.5, speed: 12.71km/h, cal>
Aug 24 23:27:25 rowingmonitor npm[701]: stroke: 11, dur: 1.65s, power: 106w, split: 02:29, ratio: 0.39, dist: 73.7m, cal: 4.3kcal, SPM: 37.2, speed: 12.08km/h, cal>
Aug 24 23:27:27 rowingmonitor npm[701]: stroke: 12, dur: 1.65s, power: 119w, split: 02:23, ratio: 0.41, dist: 79.6m, cal: 4.6kcal, SPM: 36.6, speed: 12.54km/h, cal>
Aug 24 23:27:29 rowingmonitor npm[701]: stroke: 13, dur: 1.65s, power: 156w, split: 02:11, ratio: 0.42, dist: 86.5m, cal: 5.0kcal, SPM: 36.1, speed: 13.66km/h, cal>
Aug 24 23:27:31 rowingmonitor npm[701]: stroke: 14, dur: 1.75s, power: 141w, split: 02:15, ratio: 0.43, dist: 92.7m, cal: 5.4kcal, SPM: 34.4, speed: 13.24km/h, cal>
Aug 24 23:27:32 rowingmonitor npm[701]: stroke: 15, dur: 1.60s, power: 138w, split: 02:16, ratio: 0.38, dist: 99.1m, cal: 5.7kcal, SPM: 35.5, speed: 13.18km/h, cal>
Aug 24 23:27:34 rowingmonitor npm[701]: stroke: 16, dur: 1.59s, power: 118w, split: 02:24, ratio: 0.33, dist: 103.8m, cal: 6.1kcal, SPM: 38.8, speed: 12.44km/h, ca>
Aug 24 23:27:35 rowingmonitor npm[701]: stroke: 17, dur: 1.68s, power: 97w, split: 02:34, ratio: 0.40, dist: 108.8m, cal: 6.4kcal, SPM: 37.4, speed: 11.69km/h, cal>
Aug 24 23:27:37 rowingmonitor npm[701]: stroke: 18, dur: 1.69s, power: 128w, split: 02:20, ratio: 0.45, dist: 115.3m, cal: 6.7kcal, SPM: 35.7, speed: 12.80km/h, ca>
Aug 24 23:27:39 rowingmonitor npm[701]: stroke: 19, dur: 1.65s, power: 115w, split: 02:25, ratio: 0.43, dist: 121.0m, cal: 7.0kcal, SPM: 35.3, speed: 12.38km/h, ca>
Aug 24 23:27:40 rowingmonitor npm[701]: stroke: 20, dur: 1.71s, power: 88w, split: 02:38, ratio: 0.43, dist: 125.9m, cal: 7.4kcal, SPM: 36.1, speed: 11.32km/h, cal>

2 replies

JaapvanEkris Aug 25, 2022

Aside from the first two strokes, it looks normal, although the rowed distance per stroke is short (4 to 7 meters), but that might be due to the high stroke rate. Was this an easy row or an intense one?

Could you post the configuration of your rower, so I can take a look?

As an aside, your stroke rate is a bit high (you really want that flywheel to spin down, so a more relaxed recovery is useful). For a normal workout, I typically aim at 20 to 24 SPM, where I have a strong drive and a relaxed recovery. My distance per stroke is around 9.5 to 10.5 meters.

roblloyd319 Aug 25, 2022
Author

I think the first 2 strokes are funky because that's me grabbing the handle and getting set . The wheel moves a little bit, then I row some actual strokes.

Stroke rate is high I think because I'm not strapped in; so I'm not doing full strokes (don't want to fly off the back, again!). I was just trying to see if stroke detection worked. I should probably take it more serious from now on.

I'll post the config when I get home tonight.

roblloyd319 · 2022-09-11T21:04:49Z

roblloyd319
Sep 11, 2022
Author

Stroke detection is good now.

I finally got a bigger drive gear installed. Now, I think it's way to hard to pull in the small cog. At least I still shift to a lower gear. But, my strokes/min went down to about 20-22. I think I just don't know how to row. I also think my ergonomics are off. I can't get to the point where my shins are vertical. I think my footboard to seat height is too short. As a result, the leg portion of my stroke seems short. Things to work on.

About power: I recorded a short session with my GPS logging the power hub. It's showing an average of 150-170w per stroke, where OpenRowingMonitor is showing 65w. I realize they're calculating differently, but it's still way off. The DragFactor seems to be close at 4500. I guess I need to paly with the inertia setting.

9 replies

roblloyd319 Sep 12, 2022
Author

Thanks for the confirmation. I'll do a longer row to see where the dragfactor stabilizes, and update my setting.

Here's the test in Strava, if you're interested. You can see the power rising linearly with time, it stabilizes at about 2min, just before I did a little 'sprint' in EXR.

https://www.strava.com/activities/7793871180

roblloyd319 Sep 14, 2022
Author

Here's the same row, data from the rowing engine. You can see the applied DF never gets to the calculated DF (seems to be average = 46,000). I'll update the settings to start the DF at 46,000.

https://live.staticflickr.com/65535/52357380338_d37e0ee09f_c.jpg

roblloyd319 Sep 15, 2022
Author

I think I got it, finally. Here are my current settings:

    rowerSettings: {
      createRawDataFiles: true,

      numOfImpulsesPerRevolution: 4,
      minimumTimeBetweenImpulses: 0.04,
      maximumTimeBetweenImpulses: 0.16,
      smoothing: 3,
      maximumDownwardChange: 0.825,
      maximumUpwardChange: 1.175,
      flankLength: 5,
      naturalDeceleration: 0,
      autoAdjustDragFactor: true,
      dampingConstantSmoothing: 5,
      minimumDriveTime: 0.4,
      minimumRecoveryTime: 0.8,
      flywheelInertia: 1.5,
      dragFactor: 16000,
      magicConstant: 2.5,
      numOfPhasesForAveragingScreenData: 3,
    },

These seem to give a reasonable power and stats. At least, as far as I can tell. I'll have to do some real rowing to see where I'm at.

JaapvanEkris Sep 16, 2022

Hi Rob,

Is there a specific reason for setting the magicConstant to 2.5? The magicConstant essentially determines the velocity given a specific power, so essentially you are changing it to a lighter boat where the same power will give you more speed. Wouldn't it be easier to adjust flywheelInertia and the resulting dragfactor?

Jaap

PS: the createRawDataFiles insde the rowersettings doesn't do much, it should be in the outer settings of the config.js

roblloyd319 Sep 16, 2022
Author

I was playing around with settings and forgot to change that one back to 2.8.

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Configuring a home-built rower #80

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Configuring a home-built rower #80

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