Anyone tried KST DS245S servos?

[CBR240]

Originally Posted by myxiplx

Aren't the Align servos about the same weight as these but a little faster? My DS410 servo spec looks very similar.

The specs I see for the DS410 here:
http://www.servodatabase.com/servo/align/ds410

look identical, except the Align DS410 weigh 12.7g and the KST DS245S weight 9g. If I could find a DS410 not attached to a Heli, I'd weight it. I've weighed the 245S at 9g. Both have identical speed and torque. Such as at 6V both 2.2 K and 0.09 sec. At same voltage they have identical spec, but the KST weight less.

[gimbleguy]

Originally Posted by myxiplx

Aren't the Align servos about the same weight as these but a little faster? My DS410 servo spec looks very similar.

the 410 is similar weight to my hitecs around the 12g mark. the 410 is not full metal gear. Also it's single bearing.

The ds245s is dual bearing(less slop build up, much stronger to with hold a crash), coreless motor(fast and efficient), full metal gear and weighs at 9g according to it's specs.

Only down side to the ds245s is the exposure of wires from the motor, that's the only thing that's putting me kinda off it.

PS. The only servo that I know of that can match this servo in weight and price, is the MKS DS480.
http://www.amain.com/mks-ds480-metal...-servo/p207978
DS-480 Specifications:

• Dead band: 0.002ms (Default)
• Control System: +Pulse Width Control
• Working frequency: 1520μs / 333hz
• (RX) Required Pulse: 3.0 ~ 5.0 Volt Peak to Peak Square Wave
• Operating Voltage: 4.8 ~ 5.0 V DC Volts
• Operating Temperature Range: -10 to + 60 Degree C
• Operating Speed (4.8V): 0.068 sec/60° degrees at no load
• Operating Speed (5.0V): 0.065 sec/60° degrees at no load
• Stall Torque (4.8V): 25.7 oz/in (1.85 kg.cm)
• Stall Torque (5.0V): 26.8 oz/in (1.93 kg.cm)
• 360° Modifiable: YES
• Motor Type: Coreless Motor
• Potentiometer Drive: Indirect Drive
• Driver Type: FET
• Bearing Type: 2 Jewel Bearing + 1 Bronze Bushing
• Gear Type: Metal + Aluminum-magnesium alloy Gears
• Programmable: YES
• Connector Wire Length: 15.0cm (5.9")
• Dimensions: 22.5x10x23.5mm (0.89x0.39x0.93")
• Weight: 9.5g (0.335 oz)

Only down side to the DS480, is that you need to keep the voltage under 5v any more than that can lead to a servo burn out. As for the 245S it too has it's voltage limits, no more than 7v! Use a voltage regulator if your system is running high voltage.

One last thing with the DS480, it's programmable, which can have incompatibility issues with some gyros that puts out a pulse on initialisation and which is the same pulse for the servo to go into programming mode. Which renders the DS480 useless. Beware of programmable servos

[CBR240]

Originally Posted by gimbleguy

...
As for the 245S it too has it's voltage limits, no more than 7v! Use a voltage regulator if your system is running high voltage.

I plan to keep mine at 6V or below, but the Aloft site I linked to in first post:
http://www.alofthobbies.com/kst-ds245s.html
Has

Update October 2014 - KST tells us these servos are now rated for up to 9 volts! That makes this a very wide range voltage servo.

IDK if they changed them at some point last fall, or just got more optimistic.

Wires hanging off the motors (with the exposed motor backs) is kind of weird, but for the weight and performance I can live with that.

[wizzel1]

LOOKS NICE I WOULD LIKE TO TRY A SET OF THESES WHAT SERVO ARMS AND BALLS DID YOU USE AND DO YOU HAVE ANY PART #S FOR THE ARMS AND BALLS ??

[myxiplx]

Aaah, 9g.... I should have read the OP's post more carefully. I skimmed through it and just the 12g bit stuck in my head.

At 9g these are a nice little saving. I still want to see what Lynx bring out with their 6g servos though :-D

[CBR240]

Originally Posted by wizzel1

LOOKS NICE I WOULD LIKE TO TRY A SET OF THESES WHAT SERVO ARMS AND BALLS DID YOU USE AND DO YOU HAVE ANY PART #S FOR THE ARMS AND BALLS ??

The arms are the ones that came with the servos. I don't know where to get spares yet, but each servo comes with 3, so I don't expect to have a shortage (they are different and smaller than the KST DS113MG/DS215MG/... horns our other KST servos use). The balls are the standard Align H25055A (I think is the part#) stainless steal balls. I used the shortest balls on all, yet they are a little long for these servos when mounting "under" the arms. That's one of the quirks of their install, I can't tighten the servo horn down all the way or the ball hits the servo. They are working fine right now (I just didn't tighten them all the way and put a little blue thread lock on the screw), but I need to cut down some small washers to go under the horns.

Originally Posted by myxiplx

Aaah, 9g.... I should have read the OP's post more carefully. I skimmed through it and just the 12g bit stuck in my head.

At 9g these are a nice little saving. I still want to see what Lynx bring out with their 6g servos though :-D

I understand. After flying my 250 with these, my son wants to gets some for his 250. I suggested at this point he might want to wait and see what the new servos and frame from Lynx are like, he did NOT like the idea of waiting.

[CBR240]

Originally Posted by CBR240

The arms are the ones that came with the servos.
...

BTW - the Align 250 balls screwed right into the DS245S arms (with a bit of force). I do trim the servo horns off with cutting pliers at the next whole, then sand them round.

[myxiplx]

Originally Posted by CBR240

I understand. After flying my 250 with these, my son wants to gets some for his 250. I suggested at this point he might want to wait and see what the new servos and frame from Lynx are like, he did NOT like the idea of waiting.

Just tell him the stock Align servos are fine, that's all I'm using :-)

Trex 250 in the back garden (3 min 50 sec)

[gimbleguy]

Originally Posted by myxiplx

Aaah, 9g.... I should have read the OP's post more carefully. I skimmed through it and just the 12g bit stuck in my head.

At 9g these are a nice little saving. I still want to see what Lynx bring out with their 6g servos though :-D

6g, lets hope it has some major torque with a minimum 1.6Kg. The 250 and the oxy would really benefit from an ultra light and ultra strong servos.

[myxiplx]

I think the 6g servos will be too small for the Oxy, these 9g ones are probably as light as you can go there.

For the 250 its a bit of a gamble, but based on the 2kg align servos being good for the 450, the 250 shouldn't need anywhere near that much torque.

[gimbleguy]

Originally Posted by myxiplx

I think the 6g servos will be too small for the Oxy, these 9g ones are probably as light as you can go there.

For the 250 its a bit of a gamble, but based on the 2kg align servos being good for the 450, the 250 shouldn't need anywhere near that much torque.

welp that being said the latest 250 super combo has servos with 1.8kg minimum torque. I think I was a bit generous there asking for a 1.6Kg minimum torque. But for 6g to create a coreless, full metal gear servo, is asking to much as it is I suppose. Let alone asking for high torque and high speed.

[CBR240]

I now have 50 flights on the DS245S servos, so thought I'd report back.

After 50 flights I am very happy with these servos. They still have no slop to them at all. They feel as"precise" as the DS215 we run on our 450s collective, at less than 1/2 the weight of a 215 (but more than all the price). I continue to be pleased with how well the DS245S is holding as a tail servo. The weight saved + the precision of these servos has taken my 250 to a whole new level.

I think I can honestly say that this 250 is now my favorite Heli. I normally fly 250s in my yard, and save the 450s for the club field. But last trip to the club field I took the 250 just to let it rip in wide open space. Will not be the "new norm", but says a lot when my beloved 450L sits in the truck, while I fly the 250 at the club field.

Much to my amazement and confusion, I have not crashed with these yet. 50 flights with no crash is not the norm for me. So expect crash test report shortly.

So they take a bit of fuss to install (see my post #16 this thread), but I feel they are well worth the effort and their cost. Others may disagree, well evidently everyone disagrees, as no one else seems to be too interested in them here:

How much do I like them? I've already got 4 more for my sons 250, which he will get as soon as he finishes his English term paper (yes, I bribe my children, it works ). I'm on the verge of ordering 6 more for spares and my 2nd 250.

For one that likes to tweak/mod and is not put off by the motor wires showing on the bottom of these servos, I highly recommend them.

[CBR240]

I finally crashed the 250 with the DS245S servos in it really hard. Hit ground inverted in IU, and TH was hit only shortly before impact (milliseconds). Bent feathering shaft, bent main shaft, stripped OWB, and ...

it did strip one of the DS245S's gears. I think with the severity of the impact, that in itself is not bad (a single servo worth of gears). It does kind of suck I haven't yet found a source of gears, as these are $31 each, which makes crashing one pretty expensive.

Good news is, the Zeal blades are fine.

Also .....

[CBR240]

When looking at replacemnts, I see these:

KST X08 SERVO - 2.8KG (38 OZ IN), .09/SEC - 8 GRAMS
http://www.alofthobbies.com/kst-x08.html


A gram lighter, and the wires come out the bottom, so I would not have to hack the fame to get them in (the DS245S fit , but to get them in with the wire coming out the side, required me to Dremel the frame a little bit). I think these X08s would drop right in. I may have to get a few and see.

[myxiplx]

Sounds interesting, but they're pretty slow at 6V.

[CBR240]

I missed that. Thanks!

It's a bit confusing:
Aloft site says X08 are:
.09sec/60°@6V, .15sec/60°@6V, .18sec/60°@3.8V

And say the DS245S are:
.09sec/60°@6V, .12sec/60°@3.8V

So I was thinking they would be equivalent. Humm
For the X08, Aloft gives two different speeds at 6V. I would guess that to be a mistake. Maybe .09 is at 8.4V?. That would make them quite a bit slower than the DS245S.

I see other vendors listing the X08 at:
Speed:
0.15 sec / 60 deg. @ 6.0V
0.18 sec / 60 deg. @ 4.2V
http://www.hobbyclub.com/index.php?m...5f3b24e3356885

There is quite a bit of difference between .09 and .15. Disappointing, as I do think that's on the slow side for 250 collective servos.

[dr dremel]

I also stumbled upon the KST DS245/Hobbyking clones and X08 servos (X08 is the successor, DS245 being discontinued). They´re really interesting as they seemingly repeat the design of the bigger micro metal case servos: Putting an oversized motor in a small case, but one size down.

Now as DoubleCH over on the Protos forum has the TGY 306 on his 500 size Protos working without problems, I wonder if these smaller servos would work on a 450? Just judging from the specs they would. I´m tempted to try them on my Mini Protos.

From what I learned from the threads about these servos over on RCG, KST claims improved centering for the X08. Not sure, if the slower speed really is a disadvantage, anything faster than 0,15ms/60deg should work even with modern FBL systems.

And as these are wing servos by design, I also found the equivalent from MKS, DS65K and DS75K. 60 bucks!

[CBR240]

We use the KST DS215MG in all our 450s (for collective, DS515MG for tail). Really like them. I think they are the same as the TGY 306 you mention.
http://www.alofthobbies.com/kst-ds215-servo.html

They are why I tried the DS245S in my 250. We like the 245S for our 250s a lot. IDK about DS245S (or X08) for a 450.

[nflanagin]

So I bought the ds245s when looking for something lighter. I'm using them with a MSH uBrain. I went the whole nine yards and clipped the connectors and put on crimped JST ZH connectors which I had done with the align 416s - I really like the uBrain on this heli. You need jeweler 5x glasses to see those darn things when replacing the servo leads. I'm not done with the setup yet and maidened it today, but it does seem lighter and the servos work great. A ds76t on the tail.

The one thing I had to do was dremel out the center hole on the servo to form a slot so I could align the servo screws with the current holes in the frame. The servos are just slightly shorter in length. The only trick I did was I had old mCPX canopy grommets that I used as spacers under the servo arms so that balls had clearance.

The heli comes in at 267gr without the battery. I'm using the Zeal 210s and the carbon torque tube. This is on spektrum and I didn't decase the satellite. I also have a Bluetooth adapter for the uBrain hung on the side. I ran an 2" extension to a Talon 25 (with cut down servo and motor leads) so I could use castle link to program the Talon.

The reason for the re-build was this started as a 250plus with crash part replacements from the pro. I was playing with a new swash, spun it up and the main bearings spun in the plastic main bearing block and shattered them (and the bearings). So, what the heck, upgrade to the metal bearing block and new servos.

[CBR240]

Hi nflanagin. Yea, I've started Dremel-ing the servo mount holes into a slot also. Was drilling them, but have found Dremel is easier.and works better.
I have cut down washer under my servo arms. Was a PITA and not quite high enough. I like the canopy grommet idea. I'll have to look and see if I have any around that fit. May have to order some mCPX canopy grommets.
Only down side I've found to these so far is cost of crashes. I wish I could get replacement gears for the DS245S.

I am quite interested in the MSH uBrain. I only have ZYX FBL controllers so far, and was interested in trying something like an Icon next. uBrain looks like it might be a great option for the 250s.