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Aug 09, 2013, 03:32 AM
:)
Thread OP
Mini-Review

Multistar 1704 1900KV Motors


https://www.hobbyking.com/hobbyking/s...outrunner.html


A quick handheld test on 7.4V. These need 3S for full power. Very smooth, fast response.
(0 min 42 sec)



Well machined integrated M5 prop mount & M2 nylock to retain shaft


The nut makes adjusting clearance easy, hope they stay on!


They show their price in the windings but should still perform well






Good clearance for motor mount screws - Mount points are M2 @ 14mm diagonal


Bearing seem average but easily replaced 2x6x2.5-3mm? (don't know depth yet)


Decent size M3 shaft retaining set screw which is actually locktited!!!!!


Silicone motor wires


2mm plugs


Supplied accessories... 1mm thick alloy X-mount - 27-27.5mm diagonal mounting


Prop nut and washer


Best to replace with M5 alloy locknut


Perfect for Gemfan 5030 prop
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Aug 14, 2013, 10:23 AM
Registered User
Nice...
Aug 17, 2013, 09:30 PM
'FPV'er...not a "LOS'er
Vantasstic's Avatar
I've got some C20 2050kv motors on a small spider hex. They've been okay, but can't say I'm overly, overly impressed with them. I stumbled across the Multistar 1704 while looking for some larger, low kv motors. I'm looking forward to some test results on these. May be worth replacing the C20s....maybe...
Aug 18, 2013, 04:58 AM
:)
Thread OP
Quote:
Originally Posted by Vantasstic
I've got some C20 2050kv motors on a small spider hex. They've been okay, but can't say I'm overly, overly impressed with them. I stumbled across the Multistar 1704 while looking for some larger, low kv motors. I'm looking forward to some test results on these. May be worth replacing the C20s....maybe...
Hey mate, There's one quad using them in the Blueskyrc mini thread, and Wolfmetalfab's is up and running but he's on the road atm. I've been too busy to build this week but hopefully soon.

The initial feedback has been positive, Wolf launched his into the ceiling, so that's good

Its looking like the ZMR / RCX 1804's might still have more power, but I'm feeling like the 1704's might be a better motor overall. I looked at the bearings again tonight and I think they're 3mm deep, so 2x6x3mm which is a decent size bearing, and bigger than the 1804's. (From memory 2x5x2???) The shaft lock nuts make maintenance super easy, so as long as they stay on the 1704's should be a winner, at least on lightweight acro quads

Cheers mate, I'll get test results back asap.
Sep 16, 2013, 01:32 PM
Crash Test Dummy
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Sep 24, 2013, 07:34 AM
Registered User
Won2Race's Avatar
I recently purchased several of these to use on a 235mm quad. My initial impressions are that the motors appear to be good quality, although, the bearings are questionable. They're noisy and the bells rock slightly back and forth on all 5 motors I got leading me to believe the bearings aren't all that great. Perhaps the shaft nuts need to be tightened slightly. I'll try that soon.

Performance wise, I'm a little bit underwhelmed. I'm running mine on old 20C 1300 3s Dualsky batteries and 5x3x3 props and the thrust of the quad seems to be lacking. It hovers at well over half stick (I'd esimate around 60-65% stick position. I can't blame this on the motor as I believe that the 5x3x3's on 3s aren't enough prop. My Eagle tree data logger showed a max amperage of 12.2 amps at WOT during a climb. I believe some of my problem is the inability of my batteries to maintain voltage under high load. I have some 1000 35c 3s batteries on the way to try out. I expect performance to increase just from the smaller pack, though. I'll report back on my findings and post some graphs from the in flight ETDL data.
Sep 24, 2013, 08:48 AM
:)
Thread OP
Quote:
Originally Posted by umdpru
I recently purchased several of these to use on a 235mm quad. My initial impressions are that the motors appear to be good quality, although, the bearings are questionable. They're noisy and the bells rock slightly back and forth on all 5 motors I got leading me to believe the bearings aren't all that great. Perhaps the shaft nuts need to be tightened slightly. I'll try that soon.

Performance wise, I'm a little bit underwhelmed. I'm running mine on old 20C 1300 3s Dualsky batteries and 5x3x3 props and the thrust of the quad seems to be lacking. It hovers at well over half stick (I'd esimate around 60-65% stick position. I can't blame this on the motor as I believe that the 5x3x3's on 3s aren't enough prop. My Eagle tree data logger showed a max amperage of 12.2 amps at WOT during a climb. I believe some of my problem is the inability of my batteries to maintain voltage under high load. I have some 1000 35c 3s batteries on the way to try out. I expect performance to increase just from the smaller pack, though. I'll report back on my findings and post some graphs from the in flight ETDL data.
Yeah mate, mine were over reving with small props. If your quads light enough get some 6x4.5's from Himodel and cut them if you need to. Otherwise the 5x4.5 triples are good too. It may be your packs too as you say. 12A on a climb, with a heavy Eagle Tree on board, is very low, mines up round 24 Amps and the motors are getting warm at that

Let us know how you go
Sep 24, 2013, 10:14 AM
Registered User
I originaly purchased 4 of these for this build https://www.rcgroups.com/forums/show....php?t=1993519

Outward apperance was great, one of the motors had bad winding, looks like a long screw had been run in one of the mount holes and mangled the winding. One of the other 3 had bad bearings and was causing speed control to get hot and fault .

Ordered 2 replacement motors. Replacements arrived , Decided to do a run up on the bench before instal. Main shaft snapped on the first motor on initial run up and the other one had wiped threads .

Of the 6 motors , the one with the non existent threads never should have made it into a box and it appears the vendor HK is sourcing these from is not running any visual qc nor checking windings with a meter before they leave.

ended up swapping parts between 4 bad motors and in the end spent roughly 2 hours and purchased 6 motors in total to end up with 4 that work. The only other issue I have with these is that the prop shaft is 5mm, not a problem there but it has a pilot at the base thats 7mm in diameter which doesnt fit any of the bushings included with the props of proper size that I can find at HK.

All that aside I am very impressed with the overall performance of the 4 motors I was able to get running. I have flown quite a bit with 7x4 on 2s, which are to large for the motors at 19kv and have to be very careful not to overheat the motors. The 5x4.5-3blade props are very well matched for these motors on the quad in my build thread and it flys very well on 3s.

These seem like nice motors so far but the QC at the vendor and the lack of QC at the receiving dept at HK makes getting 4 usable motors a crap shoot. I am in no way complaining, just pointing out my observations. At the price I am still happy.
Sep 24, 2013, 11:36 AM
Registered User
Won2Race's Avatar
I have a variety of props coming from Himodel now. Should be here by the end of the week. I hope I got 5x4.5x3's. I believe I did along with 6x4.5 two bladers. 6 inch props are too long though and I'll have to cut them down somehow.

How does one go about cutting down a prop accurately? I tried it once with a 9 inch fake gemfan and it didn't turn out too well. I couldn't get it to balance well at all!
Sep 24, 2013, 04:15 PM
:)
Thread OP
Quote:
Originally Posted by umdpru
I have a variety of props coming from Himodel now. Should be here by the end of the week. I hope I got 5x4.5x3's. I believe I did along with 6x4.5 two bladers. 6 inch props are too long though and I'll have to cut them down somehow.

How does one go about cutting down a prop accurately? I tried it once with a 9 inch fake gemfan and it didn't turn out too well. I couldn't get it to balance well at all!
This is my prop cutting solution at the moment. Works on plastic too.
https://www.rcgroups.com/forums/show....php?t=2002624

(2 min 7 sec)


Meant to reply before about bearing preload as well. If they rattle just snug up the locknut until the rattle stops but no more spinning resistance is added. Also oil with good oil every session when running in.
Sep 24, 2013, 04:18 PM
:)
Thread OP
Quote:
Originally Posted by panaceabeachbum
I originaly purchased 4 of these for this build https://www.rcgroups.com/forums/show....php?t=1993519

Outward apperance was great, one of the motors had bad winding, looks like a long screw had been run in one of the mount holes and mangled the winding. One of the other 3 had bad bearings and was causing speed control to get hot and fault .

Ordered 2 replacement motors. Replacements arrived , Decided to do a run up on the bench before instal. Main shaft snapped on the first motor on initial run up and the other one had wiped threads .

Of the 6 motors , the one with the non existent threads never should have made it into a box and it appears the vendor HK is sourcing these from is not running any visual qc nor checking windings with a meter before they leave.

ended up swapping parts between 4 bad motors and in the end spent roughly 2 hours and purchased 6 motors in total to end up with 4 that work. The only other issue I have with these is that the prop shaft is 5mm, not a problem there but it has a pilot at the base thats 7mm in diameter which doesnt fit any of the bushings included with the props of proper size that I can find at HK.

All that aside I am very impressed with the overall performance of the 4 motors I was able to get running. I have flown quite a bit with 7x4 on 2s, which are to large for the motors at 19kv and have to be very careful not to overheat the motors. The 5x4.5-3blade props are very well matched for these motors on the quad in my build thread and it flys very well on 3s.

These seem like nice motors so far but the QC at the vendor and the lack of QC at the receiving dept at HK makes getting 4 usable motors a crap shoot. I am in no way complaining, just pointing out my observations. At the price I am still happy.
That's a good review. Mine weren't that bad, but not good on QC. When the duds are factored in it drives up price quite a bit. Wish they'd just done a good job and charged $15 instead of $11!!!
Sep 24, 2013, 05:13 PM
Registered User
your right, a few bucks more just to avoid the 3-4 weeks it takes to get a replacement would be worth it to me. I normaly order 5 motors anytime I need 4
Sep 24, 2013, 05:46 PM
:)
Thread OP
Quote:
Originally Posted by panaceabeachbum
your right, a few bucks more just to avoid the 3-4 weeks it takes to get a replacement would be worth it to me. I normaly order 5 motors anytime I need 4
I wish Sunnysky would play ball in this league!

A 1306, 1806 and 2206 from Sunnysky in this style would rock my world!
Sep 29, 2013, 08:49 AM
:)
Thread OP
Here's the 1704's on a AUW 230g acro quad.

(3 min 47 sec)



Pics...
https://www.rcgroups.com/forums/show...&postcount=117




Eagle Tree plot with 3S 850mAh 45C lipo



Specs...
AUW 230g I think???
U817 / U818 Frame - 4mm carbon
Multistar 1704 1900KV motors
HK F6A (UBEC) ESCs - SimonK
Lemon-Flip Pro Rx - FC
3S 100mAh 45C Nanotech
Oct 17, 2013, 03:09 AM
Registered User
Hi I found this warning on my new Turnigy 1704 motor box: "WARNING: This
product contains chemicals known to the State of California to cause cancer
and birth defects or other reproductive harm."

I'm from Europe and I don't know anything about California laws but....
should I be nervous to use this motor...? :-) What chemicals can be used in
simple brushless motor?

Thanks


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