Thread Tools
Nov 11, 2007, 09:40 PM
Dave North
timocharis's Avatar
Thread OP
Discussion

Microdan 2510 Do-It-Yourself Kit


Nice looking motor, huh?

As kits go, this one is about as easy as it gets. Magnets are already installed, bearings in place, etc. All you have to do is wind the motor, slip the bell on the stator and insert the clip. That's it; there is no thrust washer and the shaft is not adjustable.

Though there's a little confusion on winding count, the single most remarkable thing is: the motor delivers exactly what Dan said it would. Or rather, he claimed about 34oz thrust @ roughly 16 amps using a GWS 1170 HD prop.

Here are my results from my second test wind:

GWS 1170 HD TP 1320 3S:
6701 rpm @ 10.34v/16.00a 964 grams 34.000 oz/thrust

Note the zeros after the decimal on the thrust and amp numbers. That's for real. To any reasonable resolution, this motor delivered _exactly_ what the manufacturer claimed.

Well, not really. That thrust is calculated based on various temp and pressure assumptions -- my scale read about 37 oz thrust. In other words, it's already outperforming spec.

In my experience, motors don't usually come very close to spec. They almost never outperform! Count me as a new "Dan Fan."


Dave
Sign up now
to remove ads between posts
Nov 11, 2007, 09:46 PM
Dave North
timocharis's Avatar
Thread OP

The Wind


The quoted wind for the motor was 7 turns of 23awg wire. To get a reference, I started by putting that together. Very easy wind, but the results were fishy:

Microdan 7T 23swg Wye

GWS 1170 HD TP 1320 3S:
6864 rpm @ 10.5v/19.1a 1063 grams 37.5 oz/thrust
APC 11x4.7sf TP 1320 3S:
6442 rpm @ 10.3v/20.5a 1150 grams 40.6 oz/thrust 64.6% Efficient

Too much power all around, and fairly sad efficiency. What's up with that? Looking at the data, it seemed like a classic "off by one" error. Different people count their turns in different ways, and this can lead to counts of the same motor disagreeing by one turn. It looked to me like 8 turns was the right setup to match stock.

So I did it, and that's the motor you see below. However, the 23awg was so easy I decided to take it to 22 gauge, which was also a pretty casual wind. Here's the full data set:

Microdan 8T 22swg Wye

GWS 1170 HD TP 1320 3S:
6701 rpm @ 10.34v/16.00a 964 grams 34 oz/thrust
APC 11x4.7sf TP 1320 3S:
6375 rpm @ 10.25v/17.5a 1111 grams 39 oz/thrust 72.8% Efficient

Excellent power and efficiency numbers for this class of motor!

I did a fairly sloppy job since I didn't expect or intend to keep this wind -- however, I'm going to stop here for a while and fly it to get an idea of whether I want to pursue more power or better efficiency.

The plane will tell me.

Note the thin-coated stator; this can be a danger for getting shorts, but they solve this problem by coating the upper and lower surfaces with a generous slather of goop. This is a fine design -- the best of both worlds.
Last edited by timocharis; Nov 11, 2007 at 10:16 PM.
Nov 11, 2007, 09:51 PM
Dave North
timocharis's Avatar
Thread OP

Flux Ring


The flux ring is pressed in under the aluminum bell housing. Lets the motor look good without compromising performance.

Note the square magnets. I understand the theoretical advantages of curvies, and have seen some gain from using them. Nevertheless, I'm kind of agnostic on this subject, as I've also seen very good results when flat mags are used.

Obviously.
Nov 11, 2007, 09:55 PM
Dave North
timocharis's Avatar
Thread OP

Bell


The bell looks delicate but does not seem to lack strength. So it's kind of fun.

The integrated prop saver screws are probably going to come out -- Dan assured me they serve no function as regards the shaft. Like many such savers, they are so close to the bell that it's a fight to get my surgical tubing on.

The hub is sized for GWS HD/DD props, which is a good choice. But if you want to run something else, I'm not sure what the approved approach is. Also, the supplied O-ring was inadequate to retain the 1170 HD prop, but my surgical tubing was up to the task.

For the APC prop tests I just put on a collet. There's plenty of shaft to use any method you like.
Nov 11, 2007, 09:59 PM
Dave North
timocharis's Avatar
Thread OP

Back


Here's the rear view hooked up and ready to go. You can kind of get an idea of the air gap -- it's pretty small and very consistent side-to-side. The bearings seem to be good quality with no noises or excessive play.

I did put a clip on before running it, honest!
Nov 11, 2007, 10:01 PM
Dave North
timocharis's Avatar
Thread OP

Odd Thing #1


There were a few oddities about the setup. The first thing I noticed is a couple of the stator blocks were not seated quite right, nor were the stator blocks aligned perfectly to each other.

I have no idea whether this matters much or not.
Nov 11, 2007, 10:03 PM
Dave North
timocharis's Avatar
Thread OP

Odd Thing #2


Also, the stator is longer than the magnets. In the front, the stator and mags align pretty closely. But the stator extends out the rear a bit. Another "beats me how much this matters" situation.
Nov 11, 2007, 10:08 PM
Dave North
timocharis's Avatar
Thread OP

Presentation


This is a BIG motor, and it has real presence. To give you some idea, here it is next to an Axi 2212-series motor, which is roughly in the same class. The photo doesn't really do the impression justice -- the MicroDan just has a hefty look to it.

But: it only weighs two grams more than the Axi as both are shown here.

So what you have is exceptional power, very good efficiency (better than the 2212 tested), light weight relative to power, and solid quality.

I haven't yet really pushed the winding at all hard, but I expect even more power and efficiency as the wires get dialed in.

But already it has better numbers than any competing motor I've tested in this weight range.
Nov 11, 2007, 10:14 PM
Registered User
Dr Kiwi's Avatar
You are right in that your 6701rpm (some tach you must have!) should be more than 34oz - I measured 34.40oz @ 6450rpm with that 11x7 on my 2510-3D.

Your wind must be a little hotter than my original production model since I got that 6450rpm from 10.9v/17.10A/184W.

Maybe I need another of these motors - mine is unfortunately at the bottom of the TN river!
Nov 11, 2007, 10:22 PM
Dave North
timocharis's Avatar
Thread OP
Phil, that's a readout from an Eagle Tree data logger averaged over the "flat part" of a run. I have no idea how accurate it really is (I'm using the "brushless sensor") but it reports in fractions of an rpm!

I bet this actually is the stock wind, and the extra RPM are coming from using one gauge thicker wire (lower resistance = smaller voltage drop. Sort of acts like "hotter" Kv without actually being so). I'm pretty sure I could go another gauge yet, down to 21awg, but that might cause more current draw. I'm also thinking of going 15T delta in 24 awg or swg; that might cool it down a bit while adding more copper.

That's why I have to run an "air test" to see which way to go! But I'm pretty sure wind #3 will do it for this one once I know.


Dave
Nov 11, 2007, 11:17 PM
Same Day Delivery
mike3976's Avatar
Nice review of the 2510 Tim, I built my first one years ago, MD sold me the bell, and I got the stators and mags from GB! She's a brute!
Nov 12, 2007, 12:26 AM
Dave North
timocharis's Avatar
Thread OP
Hey, that's a neat pic! Hope you used the timer to shoot it...


Dave
Nov 12, 2007, 08:13 AM
www.gobrushless.com
Quote:
Originally Posted by timocharis
There were a few oddities about the setup. The first thing I noticed is a couple of the stator blocks were not seated quite right, nor were the stator blocks aligned perfectly to each other.

I have no idea whether this matters much or not.
Stator laminations are supplied in 2mm thick stacks, five of these stacks are used to make the 2510. We use special tooling to line them up. Variations in coating causes the gap between some stacks and has no effect on performance. Alinement of the stator heads is not perfect as you noted but has no effect on performance as long as it does not vary more than shown, we use a tool that lines up the stator on a pin which keys to the groove in the stator bore.
Dan
Nov 12, 2007, 08:22 AM
www.gobrushless.com
Quote:
Originally Posted by timocharis
Also, the stator is longer than the magnets. In the front, the stator and mags align pretty closely. But the stator extends out the rear a bit. Another "beats me how much this matters" situation.
The stator is close to 1mm thicker than the magnet length and should extend past the magnets in the front as well as the back....just hard to see it in the front.
Dan
Nov 12, 2007, 08:29 AM
www.gobrushless.com
Quote:
Originally Posted by timocharis
Nice looking motor, huh?

As kits go, this one is about as easy as it gets. Magnets are already installed, bearings in place, etc. All you have to do is wind the motor, slip the bell on the stator and insert the clip. That's it; there is no thrust washer and the shaft is not adjustable.

Though there's a little confusion on winding count, the single most remarkable thing is: the motor delivers exactly what Dan said it would. Or rather, he claimed about 34oz thrust @ roughly 16 amps using a GWS 1170 HD prop.

Here are my results from my second test wind:

GWS 1170 HD TP 1320 3S:
6701 rpm @ 10.34v/16.00a 964 grams 34.000 oz/thrust

Note the zeros after the decimal on the thrust and amp numbers. That's for real. To any reasonable resolution, this motor delivered _exactly_ what the manufacturer claimed.

Well, not really. That thrust is calculated based on various temp and pressure assumptions -- my scale read about 37 oz thrust. In other words, it's already outperforming spec.

In my experience, motors don't usually come very close to spec. They almost never outperform! Count me as a new "Dan Fan."


Dave
Most of the MicroDAN published data is underrated because we continuously improve the motors and we would much rather publish the performance numbers a little low compared to the other way around. We want our customers to be pleasantly surprised
Dan


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Mini-HowTo do it yourself smoke kit? spitfire123 Engines 21 Oct 21, 2009 08:13 AM
Found Microdan 2510 DIY Kit timocharis Aircraft - Electric - Power Systems (FS/W) 9 Nov 08, 2007 11:34 AM
Post your do-it-yourself photos here! Martin Hunter Parkflyers 35 Jun 25, 2002 11:08 AM
Do-it-yourself Fast Charger stefanv Power Systems 3 Feb 14, 2002 08:04 AM
Do-it-yourself Battery pack info... dmarnel Electric Heli Talk 5 Jan 12, 2002 05:34 PM