ScottAllyn's blog - RC Groups
Shop our Airplanes Products Drone Products Sales
ScottAllyn's blog View Details
Posted by ScottAllyn | Jan 13, 2017 @ 12:27 PM | 3,929 Views
I'm home sick today and too uncomfortable to spend any time doing bench testing... Instead, I thought I might do a bit of weight lifting! Introducing the CargoWhoop:



This baby has brand new 19,000kV motors and a large capacity WhoopBed for hauling around calibration weights. Power will be delivered by a CrazePony 230mAh LiHV battery, which currently puts out more power than any other gumstick-style battery that I've tested. I'll test it with 2, 3, and 4-bladed props.

The test itself is simple. From the floor at my feet, if it can fly as high as the armrest on the couch, it'll count as a PASS, otherwise it'll be a FAIL. That's high enough to get out of the ground effect, which would cause erroneous results. If it passes, I'll add a little bit more weight, in 1g increments, until it fails.
A little side-bar on ground effect... One of the reasons that I do my bench tests with the motors inverted, blowing up into free space, is to avoid the ground effect, which was wreaking havoc with my early test results, even with the props 3+ inches above the surface. While I was able to get repeatable results from prop to prop, the ground effect seemed to interact with the various props differently; some were affected more than others and ended up with the numbers artificially skewed in their favor.
Anyone care to guess which props will be able to lift the most weight and what the All-in-weight will be for the winner (Cargowhoop, battery, and extra weights)? These numbers are...Continue Reading
Posted by ScottAllyn | Dec 31, 2016 @ 11:14 AM | 7,292 Views


With the JST PH 2.0 connector now well on its way to becoming the de facto standard battery connector for the smallest of the micro quads (Inductrix, E010, etc...), I was curious to see how well it actually holds up in comparison to the Molex Picoblade connectors that have been the standard for years. Molex rates those Picoblade connectors for 30 connection cycles, which makes them an obvious choice for battery connectors... NOT! There have been countless reports on these forums (and others) of the Picoblade connectors degrading rapidly, resulting in poor power and dramatically shortened flight times. But are the JST PH connectors really that much better? How do they compare over the long-term to the Micro Losi, or JST RCY? Let's find out!

To that end, I've purchased four new batteries from MyLipo, one with a Molex Picoblade connector, one with a JST PH 2.0 connector, one with a Micro Losi connector, and one with a JST RCY connector.

The Test Plan
My plan is to collect initial performance numbers on these four batteries (already done) and then fly them regularly in a Tiny Whoop and retest the batteries every 10 to 15 cycles. This is a much less boring alternative to repeatedly connecting/disconnecting charging/discharging the batteries on the bench, tho it will obviously take longer. It will also put the connectors through the same use and abuse that everyone else puts them through in normal use (repeated connection cycles, stress from crashes, etc).

Each battery is
...Continue Reading
Posted by ScottAllyn | Nov 15, 2016 @ 06:56 AM | 19,102 Views
I was looking for my little motor and prop testing post earlier today so that I could update it and ended up digging through a number of pages before actually finding it. I figured I'd copy the data here to this little RCGroups Blog section so that I don't have to keep digging and if anyone else finds the information useful, they can find it more easily here, too!

I'm treating this as a live document and I'll post a reply to the thread when I've made significant updates.



These tests are not scientific and the setup is pretty crude, but I think the results are useful. Decide for yourself and lemme know what you think. Just don't be mean; I'm a delicate flower!

Testing Methodology
The fixture pictured above is what I'm currently using for these tests; it's permanently mounted to that scale. The scale measures grams with a resolution of 0.01g. I've found it to be accurate and repeatable down to ~0.02g. I was initially concerned that having the motor cantilevered out from the center of the scale like that might throw off the readings, but I've placed various calibrated weights on the motor mount, ranging from 0.02g all the way up to 65g and the reported numbers were spot on. The 100g weight helps dampen the fixture and stabilize the readings. The motors and props are oriented upside down so that the direction of thrust pushes the motor down into the scale. This allows the prop wash to go into free space and prevents it from hitting the scale (or getting recycled back into
...Continue Reading
Posted by ScottAllyn | Oct 14, 2016 @ 07:25 AM | 26,316 Views


Some people who have dropped a BeeBrain Flight Controller into their Inductrix frame have been disappointed with the results due to how different it feels from the original Inductrix flight controller. This got me curious to see if I could re-tune the BeeBrain to behave more like the original flight controller (mostly by fiddling with the rates and expo). Below are the settings that I've come up with.

My goal with these settings is not so much to match the flight behavior of the original controller exactly; I just want to get it within the same ballpark. To get it to be an exact match would require waaaaaay too much switching back 'n forth between flight controllers; I'd rather spend that time smashing my Inductrix into the walls zooming my Inductrix around the living room! People who are new to flying more advanced quads (or those who just prefer the feel of the original Inductrix) might find these settings useful as a starting point.

Unfortunately, I haven't found any way to do this entirely within Betaflight since the Inductrix flight controller has a bit of throttle mixed in with both pitch and roll, something that I don't think can be done in Betaflight. Most decent radios (and even some budget radios) have Mixer settings, however, so the throttle mix can easily be handled on the radio side.


A Word About PIDs
You may find that the PIDs in the screenshots below vary from your own. In most cases the PIDs in my screenshots are from earlier pre-release firmware
...Continue Reading
Posted by ScottAllyn | Oct 05, 2016 @ 03:18 PM | 7,780 Views
In order to make this data a bit easier to manage, I've moved it over to a new blog post/thread and split the data up into multiple posts.

https://www.rcgroups.com/forums/show....php?t=2778460

Please use that url if you link this data anywhere else. You can also now link the individual posts for 6mm, 7mm, and 8.5mm motor data!

Editing this one large post was becoming a headache and it was only going to get worse as I added more data. I'll close or delete this older thread if I can figure out how to get the replies moved over to the new one, since I'd hate to lose all of the existing posts.