View Full Version : Tower Pro MG90 servro mounting tab thickness?

07-13-2011, 09:14 AM
http://www.valuehobby.com/product_details.php?category_id=19&item_id=316 This is the servo, i've seen posts here about using them on Esky helis as replacements for the stock servos. I need to know how thick the mounting tabs are? Stock K-3 frame has a fairly thin slot that the mounting tabs have to fit into. Just curious if the Tower Pros tabs are the same thickness as the Esky servos.
When blinking was still a stock machine we put hs65mg's on it, and had to thin down the mounting tabs to about halfway so they would fit in the slot. Debating whether to change over to TP's or stick with the Esky servos. Gonna need to get some more gears for the Esky's soon or make the switch. If the tabs are the same thickness, it would be a plus toward changing over
So if any of you have an old TP servo laying around, would you please post the thickness of the tab? Thanks

07-13-2011, 11:50 AM
On my way into work right now. (short day) I will see what I can do for ya when I get home. I have a set of sg90 servos on my bird. Off hand guess I would say the t-pro servo mounting tabs are almost 2x as thick as esky ones.

07-13-2011, 01:40 PM
Sounds about right walterj, Eskys tabs are 1mm thick, and the Hitec are 2mm. Got a little time before needing to decide. Found a 4 pack of Esky servo gear sets for about $11 on ebay, and that should keep the servos working longer than the rest of it will hold up.:rotf

Never had an Esky servo burn out or start jittering, its always the 2nd gear that breaks a tooth. That gear can be turned 180deg and reused to get the most mileage possible. :thumbup:

07-13-2011, 02:04 PM
I have done that too; spin the gear and keep flyin. I am going to be ordering a few of these fairly soon. http://www.xheli.com/servo-mg90.html
after these I will be looking at some Hitecs.

07-13-2011, 06:19 PM
LAK, I do not have a digital caliper so my measurements are in inches(sorry). The esky servo mounting tab measures .039. The t-pro sg 90 servo I have measures .095 on my dial caliper. Almost 3x as thick wow! Who'da thunk it??? Hope this helps you.

07-14-2011, 03:43 AM
I guess there isnt a standard tab thickness. Switched the calipers to Imperial measurement mode, yep Esky's are .039, and Hitec 65 tabs are .082. Proly arent many helis on the market that uses a retaining slot as a servo mount like Esky. Theyre Special.:D

Thanks for the info. :thumbup:

07-14-2011, 08:23 AM
i had the same issue lak...i could not find a servo the same, not even hk has one :thumbdown:...i think this is another "make it like that so they keep using our spares" deal.
another reason to get shot of the thing :D no disrespect to you guys with kings...i just couldnt wait to sell mine :peace

07-14-2011, 10:12 AM
I will make the servos work. I dont care if I need to mod the servo or the frame. I will make it work.

07-14-2011, 09:03 PM
Hey Kite,

I was using HXT900's on my King 2's and they worked great. Basically the same size as the SG90. They are not metal gear though. I have been using the MG90s's which is slightly shorter than the MG90 and a little faster. I really like those on my 450's. They look a little big for the King, but might work. On the King 2, the key dimension is the height of the case as the front servo is stacked toward the rear ones. So it needs to fit that way. You can get some room by clipping the little servo mounts, but that cnly gets you about 3 mm.

Hope that helps.


07-15-2011, 07:19 AM
Well, guess i'll stay with Esky servos on the stock k-3. Gears are cheap, and easy to replace, boo-boo's are fairly infrequent nowdays, and the servos themselves are fine for the heli. Thanks for the inputs guys. :thumbup:

Wrench 54
07-15-2011, 09:06 AM
I ran the TP SG90's on my stock K2 frame and they fit with a little shimming and trimming of the servo mounts, sounds like Esky changed the way servos mount on the K3 so if there was a diff in tab thickness that sure would cause a problem, now with the CF frame I use Hitec 65's on the head, also use them on the 450 head with good results, if your getting good use now out of the stock servos and like you said the gears are cheep stay with them---------Fly Tight

07-15-2011, 11:48 AM
Pic for those who dont know what i'm talking about. The slot right in front of the white arrow is for two cyclic servos. Its only 1 mm wide, and the bottom servo tabs have to slide into the slot. Cant really widen the slot because its already a weak point in the plastic frame. As you can see, we generally have a spare frame ready to just swap over the electronics in the event of a frame breaking crash.

07-15-2011, 09:15 PM
Hi Kite,
Wow, I had never seen one apart. I see what you mean now. I checked some of my servos I have laying around waiting to be installed. Corona DS919MG's have a much thicker lip, similar to the HXT900's and SG90 and MG90 and MG90S. However, the Turnigy TGY1800A has a 1mm lip and are 3 for $9 at Hobby King. I am putting a set in a HK250GT when I get around to building it. I guy recommended them to me and they look pretty good. Made by PowerHD. If you want to go uptown, the MKS DS480 also has a 1mm lip and metal gears. It makes a great tail servo or just use them all around. Metal gears, pretty strong and very fast. They have the same thing with higher torque and slower speeds DS450, 460, and 470. Hobby King has been out for quite a while, but they can be had elsewhere for higher. The last one I bought was around $23. I actually never had any problems with the Esky servos other than the gears stripping. The King 2 came with z bends in the servo horns. It is a big improvement just putting balls and links in the servo horns!