Servo mounts

[Solitaire]

Many higher end servos require grommets to mount, but don't always come with these grommets (see pic). Can these be purchased separately, and if so, where?

[ranben]

Sorry Sol,

Im not realy sure what you are asking unless your talking about the plastic nuts that go on the screws. Im intersted in knowing the answer to your question though. I ordered the same servo. Still waiting on it.

[Solitaire]

Hi Ranben

The pic of the servo shows the mounts with not holes, but openings. I have this mounted on my EXI for rudder, but with the holes not enclosed, the servo tends to wiggle out of alignment.

It wouldn't be so bad if the boom mounts were a solid one-piece, but a you know they are in two pieces. I may have to drill actual holes beside the opening to secure the servo properly.

I've seen Align servos with mounting grommets that slide into those openings. They serve to hold the servo in place as well as provide some vibration dampening. I've just never seen a supplier for them.

[ranben]

OK.......I see what your saying Sol. Just a thought if you cant find the grommets.........can you make a gasket with a rectangular hole for the servo and two smaller holes for the screws? Dont know what you could use, but the material (if you could find it) like the HB rotor head gasket might work. Just fishing here

Something like this ? www.helidirect.com/product_info.php?products_id=4901

You could try to PM Mike of KA-Planes. He might know what to do or have them. (MikeK0416)

If you find something that works, post it if you will. I will have the same problem when mine gets here. I will keep looking.

[Doozer]

yep you can buy them. Unfortunately they get packaged with crap you don't need...

store.rcsupersales.net/servlet/-strse-3283/Logitech-3100G-Servo-Horn/Detail

I'm thinking those should work.

[akphill]

ok the answer is take some canopy mount rubbers and push them in the cut outs on the servos then find some copper tubing the same depth as the grommet insert in the middle then put the screw through to the screw hole and tighten this will keep all severe vibration away from the servo electronics making a longer lived servo. top end servos automatically come with the gromets and sleeves and screws for mounting hope this helps and i explained clearly enough. ;D

AKPhill

[akent]

HOWDY FOLKS!!!

I made it home last night and couldn't wait to get going on the SE, since I had some boxes of stuff sitting here!!!
So, I got up at 4:00 am and started!!! (That's 11:00am Norway time, so it felt normal. Just a little darker!)

I just hovered a batteries worth through it after several problems today, and lots of experimenting...

Anyway, I have the same servos, well, the HD-2216MG, or metal gear version. They were out of the plastic geared version and these were only a buck or so more. They really are all metal!!! I swear these are exactly the same as the Xheli DMA-016's. They have the same dimples in the plastic.

What I did is use the screws that came with the servo. These have a built in washer and worked fine. They don't want to move. I did have to drill new holes in the plastic servo mount, though. The stock holes wouldn't line up. They are made for servos with four mounting screws.

[akent]

Ouch... Dam thing bit me...Blades weren't tracking right, I see.



Actually, I tried to do a fast piro and the tail twisted on the boom, just like they do on the Squadron!!! I lost control, and then it proceeded to chomp on my leg on it's way to the concrete.

Damage still being assessed.
So far, boom, boom supports, main gear, blades, flybar, blade holders, feathering shaft, main shaft, and maybe more stuff...I might have it all here!

With the SE, you NEED to pull the tail and the boom, and then put tape on there, or otherwise add some diameter to the boom. The tail sometimes gets a high frequency oscillation in it and then twists on the boom. There is not enough of a clamp the way it comes.
I don't know how to control something where rudder makes it go forwards and back, side to side, and round and round at the same time...
================
Anyway, the XM G401B gyro ROCKS!!!!!! It is ONE HUNDRED TIMES better than the Esky 704B that I have on my other Exi that Cost three times more!!!
BTW, I have not yet heard from DealExtreme on the Gyro I ordered from them. When they told me after a couple of weeks that it was backordered, I just ordered another one from www.cnchelicopter.com. I am MOST impressed with this thing! I can't wait to replace the Esky with this!

Here's a setup difference:
They Esky will drift badly in HH mode, until you setup the tail to have no drift in 'normal' mode. Then when you flip it into HH mode, it will be much better, but will still drift a lot. You can trim it out, but you have to do that every time you fly. With the setup like that, you majorly lose right piro speed.
With the G401B, you just setup the tail servo to be zero pitch with the tail rotor!! This is how it's supposed to be!!!
Piro's are very fast in both directions! Fast enough to make the tail twist on the boom, and maybe hit ones leg...
Kent

[Solitaire]

Hey, welcome back, Kent.

Thanks for the tips guys. I tend to use 2mm bolts/nylocs on my servos. Don't ask me why. Anyway, there is a 2mm flat washer under the bolt head, but it's still not staying in place.

I'll look at revamping the whole setup. Maybe go with alum boom mounts as I've pretty well trashed the plastic ones.

A dainty touch was never my forté

[Solitaire]

Kent

I guess we were posting at the same time. Looks like an ugly gash there.

Thanks for the "tape on the boom tip" and I'm glad the gyro worked out. I got the one from DX the other day, but as you can see I'm still farting around with other items.

Like a dead DX6i

[McKrackin]

I've had that same wound twice.Ouch

My tail was turning on the boom on my Trex and I had to put locktite on the boom tip.

[akent]

Loctite!! Well, I didn't think of that. Did that fix yours permanently?

I do have some red loctite. Maybe I'll try that, too.

Oh, and I found out today why some of us hesitate to use the super el-cheapo parts.
I am running the Towerpro SG90's for cyclic on the Exi SE.
Here's a weird one for ya.

I setup the whole heli, head and all. Everything looked great. It was ready to spool up.

Ok. I had the throttle curve set to 0-40-50-75-100 in normal mode.
Start to spool up and WHAT!!! It lifted off at maybe 25% throttle and took a MAJOR nosedive left. It happened so fast that it was hard to cut the throttle.
Humm, nothing broken, but the blades were scuffed some. No problem there.
Ok, I then took it and rechecked everything. All looked great.
I tried it again. SAME DAM THING! It took off with full left aeleron at maybe 25% throttle. This time, the scuffs were more, but still ok.

Then I RE-RE-checked EVERYTHING. All looked great. So this time, I tie-wrapped it to a sawhorse.
Spool up and at about 25% throttle, the aeleron servo goes FULL BORE left!!! This time, it went MORE than full bore and stripped itself out.

Ack! It just so happens that this was the lower servo in the front, so I had to remove everything to replace it. Once replaced, the servos are acting normally, but I'm not sure I trust servos with a 30% failure rate.
I had one bizarre failure out of three of these, but I bought extras!
Kent

[Solitaire]

Hmmm, I wonder if there is going to be a recall on the DX7, too

Never heard of a servo acting up like that all on it's own. It'd have to have some sort of input, I would think. Check the monitor section of the Tx for verification.

[McKrackin]

That's scary Sol.
The tail servo I toasted today acted similar.Pegged CC and burned itself up.

Guess what kind of radio I use.....DX7

The Trex 500 is completely free of any problems though.
I think the el-cheapo Exceed servo was just junk.

[akent]

Mar 8, 2009 19:53:48 GMT -6 Solitaire said:

Hmmm, I wonder if there is going to be a recall on the DX7, too

Never heard of a servo acting up like that all on it's own. It'd have to have some sort of input, I would think. Check the monitor section of the Tx for verification.

There is nothing wrong with the radio. I had the monitor on when it was on the sawhorse. When it went full bore, I looked down and it was where it should be.

After replaceing the servo, all was good.
I have just never heard of a servo failing like that. But, apparently they do, since Mckrackin had a tail servo do that, too. My guess is that the electronics probably had a bad solder joint that vibration would affect.

I was able to hover one battery through it after the servo was replaced. The second battery is where the tail shifted.

Strange stuff...
Kent