Which servos are the most popular with railway modellers?

[animotion]

There seems to be a wide choice of servos out there in the market and I was wondering if there was a particular make that railway modellers tend to use. The SG90 servos on Ebay are incredibly cheap but are they reliable enough to use for signals and points?

[Titanius Anglesmith]

I use unbranded SG90s from eBay, and I’ve had a few fail after a very short life. I have no complaints for the price but in future I’ll try to buy better ones. I made my servo mounts easy to change so it’s no big deal if a servo does fail. 

 

Apparently the genuine TowerPro servos are quite reliable. 

[Theakerr]

Like titanious I started out using cheap SG90s but had some fail and then proceeded to buy somewhat better ones from Hobby King out of Hong Kong.  I also experimented with Digital Servos and heavier load servos; there was no real benefit.  Recently i have just used my first micro servo, also from Hobby King.  Previously, I had to mount the servo under the baseboard which was a bit of a pain.  The micro servos  have a much smaller footprint allowing the signal and servo to be built as a single unit, calibrated before installation and installation as a single unit.  They work with my Mega Points controller and as an added benifit the one i have just installed is silent.

[woodbine]

From what I've been able to gather you can't go wrong with Tower Pro sg90 (ca£3.30), Hobby King hxt900 (ca£2.65) and there are others. But there are plenty of lookalikes and downright fakes out there so get them from a reliable source, who may be able to suggest others. Don't be tempted by cheapos. There are even smaller ones if you need , but have regard to the specs.

 

[young37215]

I have about 75 Hobbyking HK15178 which I use to operate signals and points from under the baseboard on an OO gauge layout. All are controlled using a Megapoints network where in nearly 4 years of use, I have not yet had a servo failure. Brackets are key in my experience of using servos for points, dont skimp on cheap ones as they are inclined to cause problems.

 

The only negative I have found is that stocks at Hobbyking can be a bit hit and miss with them taking time to replenish. I know this is part down to the pandemic but I faced a similar issue pre-pandemic. It all gets sorted in time, Hobbyking customer service is very good in my experience but the delays can be frustrating if you are in pressing need. Put another way, I recommend that you hold spare servos in stock rather than use a 'just in time' approach!

 

 

[KingEdwardII]

The TowerPro SG90 & the HobbyKing HXT 900 look like the right options for 9g servos and it is clear that many modellers have used these successfully for both turnouts and signals.

 

I am intrigued by the HobbyKing HK-5330 "ultra micro" servo, which is only 23 x 20 x 6 mm size. It has much lower torque than the 9g servos, but I think that this is going to be OK when driving semaphore signals. I aim to try out a set of these for driving a junction bracket signal, where there are 3 arms to control and where space for the motors is more of an issue.

 

Mike.

[njee20]

On 23/02/2021 at 11:48, woodbine said:

From what I've been able to gather you can't go wrong with Tower Pro sg90 (ca£3.30)…

 

How much?! I paid less than £1 each for my SG90s, they’re still that much via AliExpress. 
 

what are the microservos? Silent is appealing. 

[woodbine]

11 hours ago, njee20 said:

How much?! I paid less than £1 each for my SG90s, they’re still that much via AliExpress. 
 

what are the microservos? Silent is appealing. 

Well yes, there are plenty of sg90 servos for sale at quite low prices, but they may not be Tower Pro (or one of the other major brands). Some may be good clones and some may be counterfeit and not so good. No doubt you pay a premium for a trusted retailer (by which I mean a specialist who has a reputation to uphold) to stock and sell the brand that leads the market, but the OP asked if there were particular makes that were most used. By the same token that retailer may be able to suggest a cheaper good clone. But there isn't a fortune riding on it either way. A dud clone can be binned at £1 if it doesn't work.

[njee20]

Yeah, I think I stripped one (out of about 60), but the others have all been fine. I’ve no idea if they’re ‘genuine’ or not. 

[Izzy]

I think one of the problems with obtaining genuine Tower Pro servos is that they also make them to be sold under own brand labels and in addition make bespoke specification variations for others based upon their standard designs. As a very general rule TP can be found moulded into the base of their productions even if another label adorns them.

 

As an alternative to the popular plastic geared SG90 they also make a metal geared version, the MG90. This uses a mix of brass and aluminum gears, has no 'stops' on the gears as a result, so can revolve through 360 degrees and thus perform continuous rotation in both directions if asked/allowed to do so.  Being metal the gears of course don't break.....  The one small downside is the total gear reduction is less, 224-1 against 320-1. But they sound and run IMHO much nicer.

 

Generally their cost is higher, about twice SG90's but I just recently got some off ebay at £1.99. Own label jobs but with the TP moulding on the base. If like me you use hacked sevos then these metal geared versions are ideal.

 

[ROY@34F]

18 hours ago, KingEdwardII said:

The TowerPro SG90 & the HobbyKing HXT 900 look like the right options for 9g servos and it is clear that many modellers have used these successfully for both turnouts and signals.

 

I am intrigued by the HobbyKing HK-5330 "ultra micro" servo, which is only 23 x 20 x 6 mm size. It has much lower torque than the 9g servos, but I think that this is going to be OK when driving semaphore signals. I aim to try out a set of these for driving a junction bracket signal, where there are 3 arms to control and where space for the motors is more of an issue.

 

Mike.

I use those HK5330 servos Mike. They work very well with my Megapoints bouncing gubbins, which is the best semaphore bounce IMHO. They can be lowered down through a hole in the baseboard as a complete unit with the signal superstructure .

 

Regards, Roy

[KingEdwardII]

Roy,

 

Do you drive the Megapoints Servo Controller via DCC? 

 

Reading the Megapoints pages, it seems as if you need 1 x DCC module and 1x 12-way Servo Controller for DCC control of the servos. Have I got this right?

 

Yours,  Mike.

[njee20]

That’s right. If you need more than 12 you can either add a DCC module to each board, or buy the “multi panel processor”. Depends how many more boards you’ll need.