DjBac

I've been a very happy customer, using "Horizon Hobby" products for the past 1,5 year.
I've tried JR, Spektrum, H-9, E-flite Parkzone, Saito, Evolution etc products.

I've also used some of the e-flite e-retracts in several sizes with no problems (on the small ones).

In the past month I've installed 2 sets of 60-120 size retracts on 40-size warbirds.
According to e-flite (http://www.e-fliterc.com/ProdInfo/Files/60120lowres.pdf) the aircraft weight that they can support is between 3,63kg and 6,80kg.
The above mentioned warbirds have a flying weight (including fuel) of 3,7kg, so there is no problem on this matter.
They both are glow planes.

During the last 1 month FOUR retracts have gone bad. Which means all of them on both of the planes. I've replaced all of these and i am waiting for them to stop working again, thus destroying, scratching, maybe crashing one of my airplanes.
The setup I am using is spektrum RX, and Hyperion LiFe battery on the one and [email protected] on the other airplane.

I suppose they cannot withstand the vibration from the 2-stroke glow? I don't know and Horizon Hobby refuses to help me on this matter.

I've sent them an e-mail explaining them the situation and their answer was very simple and of-course not helpful at all.
I quote you below their reply.

Q U O T E
Hello,

Thank you for contacting Horizon Hobby Product Support.

The retracts can be used with anything as long as you do not surpass the weight restrictions.

If you should need further assistance regarding this issue please reply to this e-mail.

If you need immediate assistance, contact our Product Support staff toll free at (877) 504-0233. Our support representatives are available Monday through Friday, 8-7, Saturday 8-5 and then Sunday 12-5 central standard time.

Thank You,

Marc ‘RC’ | Product Support | Horizon Hobby | New Products at: http://www.horizonhobby.com
U N Q U O T E

After their above reply, I mention the weight of the planes and since 01/JUN/11 I have no reply from them and not expecting any.


I express my opinion, in order to help other modelers and avoid using these set of retracts, unless they want to start having problems.


Up to now I was very happy with HH, but unfortunately I am very disappointed with their attitude and lack of help on this matter.



Anthony,
Greece

SkyPilot101

Not surprised at all! Exactly what I have come to expect from Horizon, my beef was poorly glued hinges in there arfs, looked like old ca was used and made a mess. Two arfs the same way, they told me to tape the hinge line! All that talk of super customer service-Rubbish..... Chime in Horizon!

SkidMan

My Feedback: (17)

I've had a set that I really like and continue to work well for me and have people that own pneumatic and servo operated retracts green with envy, because they have been so reliable.

I'm sorry to hear that Horizon isn't  stepping up to the plate. I'm guessing that your problem is that they are not extending or retracting reliably.

Although I know that you are concerned that you will end up with another set that will not operate properly, it is not clear that you've asked for replacements under warranty. Have you? What was their reply?


Paul

DjBac

Paul,

The problem is that they don't extend at all! After a close-up inspection on one of them I've concluded that the fault is on the switch! Maybe it fails due to vibration?

After 20 days of silence from Horizon Hobby, they replied to my last email within 9 minutes (after sending them the link of this thread, in order to clearly read my situation).

Here is a quotation from their e-mail

Q U O T E

Thank you for contacting Horizon Hobby Product Support.

Product Support does not have the time to read forum posts.

If you would like to send in your product for warranty evaluation, please visit our online repair request form:
http://www.horizonhobby.com/Service/RequestForm/

Consumers outside the US and Canada should contact their local retailer or distributor. A list of International distributors may be found at: www.horizonhobby.com/StoreLocator.

Be sure to use a shipping method that will provide you with a tracking number and insurance as Horizon Hobby is not responsible for items in transit.

Be sure to include, the Service Center Request form, a letter describing the problems you’ve had, what’s included in the box, a copy of this email, your complete name, address, and a day time phone number.

Remember all warranty service requests must include the proof of purchase.

All non-warranty services are charged a minimum of ½ hour of labor and labor is $30 per hour (subject to change without notice). All charges for service parts, labor, shipping and other fees are your responsibility. Nonpayment can result in confiscation of equipment.

If you do not fall under our warranty you have the option to purchase any needed part/s from our website and do the repair yourself.
U N Q U O T E

I am not willing to go into all this trouble, in order to have problematic retracts again, thus damaging any of my airplanes!

No more E-Flite E-tracts for me and a lot of our club members!

Oberst

Funny, I've always had great service from Horizon. Matter in fact I bought a second (after I crashed the first one) Seagull .90 Extra 260 and the fuse was a little crushed. I sent them a picture of the damage with my phone #, they called me and they sent me a new fuse and a canopy hatch! No questions asked! Cost them $100 including shipping.

I told Horizon over the phone that- because of my skills as a builder, that I might be able to fix it without anyone ever knowing the damage ever happened. I asked the Tech that if I did my method of repair would it work? And the Tech said he said that he wasn't sure. But that he would send me a new Fuse anyway and that he would do all the paperwork for me.

He also said if my repair didn't work to use the old fuse as firewood. Like I mentioned, I repaired the damaged fuse and it looks as if it was never crushed and it still has its original covering. So now I have a brand new fuse still in the box incase I ever need it.


My cowl and guns on my Fokker DVII I had to replace 2 years ago because of shipping damage, and they sent me new ones no questions asked. I had E-flite MCX issues and they sent me a new MCX Helicopter after we tried exchanging the board, and they sent me another bad board. I sent the helicopter and new board they sent me under warrenty and they sent me a new BNF new in the box. The Helicopter is now over 3 years old and I still fly it around the house driving my wife crazy.

What I think is going on here is Horizon hasn't had many problems with the new retracts, and needs better proof that they went bad. Use the warrenty like I did with the MCX. Most of the time they don't try to fix it and just send you a new one and record the transaction in there data base.

I will always buy their products, and many of the employees are in the hobby themselves. Products from China are always a hit and miss, it's wrong to bash a product because you had a miss. From reading what you wrote it seems that Horizon is willing to help you out. It's just going to take a little work on your part because the price of the retract is about $150. Horizon it seems want to help you without making a bigger loss for themselves which is understandable in this bad world economy.

I wish you luck. I've always bashed companies in the past I felt did me wrong. But the more I think about it, I was wrong for doing that. I also think it's wrong to come to RCU to rant and ask for a boycott because of one bad experience. Anyone who knows me knows I always over react, and no good ever comes out of it. JMHO

Let us know what they find once Horizon gets your retracts, they will send you a Email the day they get it for inspection. If enough people complain to Horizon about problems they are having with the retracts, they will do a recall and will upgrade what ever goes bad on them at no cost to you.

Pete

DjBac

Pete,

I've had good service from Horizon too, just e-mail support, since there was not any need to send anything for repair!

I love a lot of their products and for sure will continue using them!

What I don't like is treated like that! When explaining my problem they didn't even reply to me. This not service support that you would expect from such a company.
I don't think I would like the retracts to be repaired/replaced (I've already paid for 4 replacements) and have the same problem again and again!

DjBac

Finally Horizon Hobby settled my problem, although it took them so long!
Once more an HH happy customer!

mikes68charger

My Feedback: (34)

I to have been haveing big issues with these retracts,

FYI if you use them in a gas bird, even well below the weight, the vibrationscan causes the positive wire on the servo motor to shake lose and disconect( while I was flying of course).When this happened Iguess italso shortedoutthe bord some way, (the motor with turn but it gose all the way to max and get stuck) I onlysoider it back togeatherBecouse this set has beenreplaced already-they already replaced them the first timebecousetheservos screw just riped out while taxing. They told me they would no longer help me with these retracts.

I have 2 complet sets of the 60-120 retracts, and I was just starting to really like them, and was going to get a tryic set up for my Hanger 9 B25 but It seems like I have to order a exstra set to have spair parts.

As that is why Horizon is haveing issues with these. Unlike other retracts out there, there are no replaceable parts of these retracts (Except wire gear). So if something gose bad, its a $65 bad.

Oberst

I just bought the retracts about a few weeks ago. They seem to work fine for now. Very good quality. If they go bad I'll let you all know.



Pete

Idris

I too have been having serious problems with a 60/120 pair bought recently - clear design errors, particularly in using a 6% efficient leadscrew, leading to the need for high currents and large batteries and the risk of going flat See my postings on http://www.modelflying.co.uk/forums/...91&p=2#1218304 for full details.

I am not prepared to put these in an aeroplane as I cannot even get them to work reliably on the ground - and my first RC retracts were in the late 1960s!

Broken Wings

My Feedback: (20)

Thanks for the "heads-up"....

stuntflyr

Guys have been having a lot of trouble with wiring and circuit boards with E-Retracts on Classic Pattern tricycle gear models, too. They can't take the vibration. I saw three models have nosewheel extension problems after as few as 1 (one) flight at a recent West Coast event!
Chris...

Idris

please refer to new posts, including mine, on http://www.rcuniverse.com/forum/post...323&toStyle=tm

They analyse the mechanical problems and suggest solutions

Reliability in terms of limit switches and unwanted cycling is something else again though.

Idris

My attention has just been drawn to an article dated Nov 2010 on this web site http://uk.reuters.com/article/email/...85P05Q20120626. It refers to Down and Locked who convert air systems to electric, but rather expensively it seems.

At first glance:

They too use a very fine threat threaded rod which inevitably suffers from the same frictional losses.

It is liteally impossible that they take only 35mA when operating - the losses must be far more than that.

There appear to be no limit switches nor is there any mention of current trips as such.

However they do take 1,600mA for 2 seconds when locking and my guess is that their electronic control box simply measures the stall current at either end and then kills the current once locked, relying on the non-return nature of the screw threat mechanism.

No information on the motor, or of any gearing to reduce losses and the fine thread suggests that there is no gearing

Idris

never a dull moment - it has already been done! See http://www.youtube.com/watch?v=Anp8l...eature=related. about 1 year old.

Small motor, 1 or perhaps 2 stages of gearing. What puzzles me though is that the thread still seems to be quite fine - perhaps its a high speed motor that needs a lot of gearing down.

No sign of any limit switches, and judging by the sound and movement it relies on sesing the high current when the drive stalls at the end, and switches off.

More electronics than I would have expected.

chuckk2

The E-Flite 60-120 gear has two limit switches on the underside of the circuit board. The 1.6A current shows that there is a problem, and the current protect is probably tripping before the brass "T" trips the switch.
After messing with two main gear units, and testing a second set.
Binding may be occurring in one or more of a few places. Side plates, brass "T" end shoulders, gear forks and cross shaft.
When binding is (mostly) eliminated, the current drops drastically to between 300 and about 400ma, with both main gear in transit.
Slop between the brass "T" and the lead screw, along with friction from the side plates may cause the brass "T" to move slightly more against one side plate. This can cause the brass shoulder to drag against the side plate. If the gear was in the retracted position, the gear may stall, due to over current trip before it gets the brass "T" out of the side plate cam detent.

The side plates have three screws with hex flat heads. Loosen the screws on one side. This may actually reduce the binding, and allow the gear to operate without tripping the current limiter.
With the side plate rotated or removed, check the brass "T" shoulders for a sharp edge. This might be a source of binding against the side plate.

With the gear set I have, rotating one of the brass "t"s 1/2 turn on the lead screw, and adding fine oil lubrication to the works, along with adjusting the side screw torques removed enough of the binding to lower the current draw to well within specs, and provide more or less reliable gear operation. I have yet to mount the gear in the model it's intended for, so I don't know how that will or will not change things.

To someone with more time and tools - - I'd suggest polishing all the sliding surfaces - - side plate cam area, gear fork slot, and removing the sharp edge on the brass "T" shoulder.
The side plate cam slot "knee" on the retract end might also be modified slightly to reduce the initial load (current draw) at the start of the gear extension. Done to excess, this might cause the gear to extend slightly from the retracted position, due to in flight vibration and "G" forces. There may be some side plate to side plate alignment issues, due to the screw and post method of attachment that can be exploited to reduce current draw by reducing binding.

The circuit board fits into slots on each side plate. It may be necessary to slightly bevel the circuit board edges to get it to fit properly in the slots during re-assembly.

When all is said and done - - current draw should be below the spec of 900ma as the gear starts to move out of the detents. In transit current draw should be less than 1/2 Amp, and the gear should operate reliably.

The gear mechanism seems to be designed such that when binding is present, gear retraction is more reliable than gear extension, something that is not really desirable.

Idris

Thanks for your most helptul post, confirming as it does - and more - my findings. What follows is intended to be my final assessment of these units:

As before, the fundamental design error is the use of a leadscrew, notoriously inefficient at transmitting power because of high frictional losses inherent in rubbing the two threaded surfaces one on the other. Unless of course a ball-bearing lead screw were used, though unlikely to be available in this size or suitable for the forces involved if it were. Nor does the small size of the motor help efficiency.

Having now removed the drive motor and electronics (using a cutting disc as I cannot find a Hex key to remove the screws) I can confirm that what appears to be just a motor driving the in-line lead screw does in fact have a tiny 3 stage gearbox built in to the end. I suspect that in those small sizes with a small number of teeth efficiency is not too good, It is at least arguable that were the overall gear ratio and the thread pitch both twice as great the inefficiency would be significantly less and available pull significantly greater. In my view the speed could be halved to improve force, and still be fast enough (though as doubling the ratio would also double the force, speed would not fall by that same factor of 2)

This might go some way to reducting the several problems which arise from such low efficiency:

1/ The system struggles to overcome friction in the lead screw and (as you mention) in the locking pin etc. My own test on a complete unit, done by holding a finger lightly against the wheel when it is being raised, shows that available pull before stalling fluctuates a great deal - a graph would be a saw-tooth. This is because of the less than perfect fits and surface finishes moving one on another. In my case the margin for error - the difference between worst running current and electronic trip - was so small as to be unusable, the slightest touch would stop the wheel moving.

2/ 5 cells instead of 4 made marginal improvements but nothing like enough to make it reliable.

3/ One time in 6 or so, one leg or the other would refuse to unlock and extend.

4/ Unwanted cycling of the controls, presumably because of the electronic trip being activated, occurred quite frequently. At times merely the metal to metal contact of a screw touched against the mounting frame would cause one or other unit to cycle.

5/ On 4 cells the maximum current when the legs continued to move, for 2 units, was close to 1 Amp. When stalled 2 Amps with a buzzing sound until the trip activated after 2 seconds or so. On 5 cells it was 2.7 Amps.

6/ Because such currents would cause terminal voltage of normal Rx batteries to drop to dangerous levels - loss of decoding, delayed recovery, and slow throttle fail safe activating - I would not dream of operating them from the Rx battery even if I could make them work reliably - unless perhaps in the smallest size - and in my view and those of others I have read, using the Rx battery is just asking for trouble.



Having removed the motor and cut off its lead screw I could operate the unit by hand. It immediately became obvious that the transverse locking pin was marginally tight in it slot, on one side. This caused it to tilt, making things worse.

It was then also clear that the sharp corners in the frames between the locking slots and the translition slots were too tight. There is no need for the corner to be sharp, so careful work with a needle file freed the whole thing up. Before doing so, even without the undercart leg fitted, pulling the linkage free from the locks took significant force, afterwards no force to speak of.

That the fit of these parts is so critical helps explain why some have problems and some do not - all depending on the clearances (which of course have to be minimal because of the 30 to 1 magnifaction seen at the wheel)

Having removed the drive system and freed up the mechanism I decided that marginal operation and unwanted cycling were simply not acceptable, and the obvious solution would be a more efficient motor with conventional gears. Fortunately I had precisely such a mechanism immediately to hand - a servo!

Initial tests showed that even with a 7" leg and 4 ounce wheel, a bog standard 60 degree Futaba ball race servo would handle the forces involved in one unit. A 17 kg cm 160 degree retract servo would of course do so with torque to spare. Because the aircraft in question is a TopFlite Thunderbolt 64" one, already built, it would have been very difficult to retro-fit the long linkages that would have to pass between the wheel wells and the upper skin to reach the centre servo bay, and bench tests showed that such long linkages need to be very stiff to prevent bowing that would prejudice secure locking at one end. And of course tricky to set up because the locking pins are not visible when installed in the wing.

Plan B was therefore to cut off one of the unwanted end of one of the frames and bolt directly to it one of the two retract servos I had to hand, so that the output arm of the servo was on the centre line of the retract unit. (A single nut and bolt will suffice as long as the far end of the servo is then supported in the wing.) By a stroke of luck I had a steel rod with a threaded end that matches the transverse pin and installed it as a push rod about 2" in length between the locking pin and the servo arm. These being proportional servos it was easy to match the travel to that of the locking positions before installing in the wing.

I had to cut away enough wing skin to allow the servo to fit, but not that much and not difficult to rework. I could have used the frame and servo to reinforce the strucure but on this wing it does not seem to be necessary.

I now have - at considerable overall expense in parts, time and frustration - undercarts which work every time, do not jam up, which lock precisely in place at either end and which have considerably more servo power available than they need - so much so that the servo does not noticeably slow down when lifting the leg. This incidentally confirms a point I made earlier, that the efficiency of the standard unit is of the order of single figure percentage points - because the servo arrangement is so much more efficient it wll not result in excessive drain from the Rx battery.

As for future retract models - at least one of the small cheap units, working on much the same principle as the mechanics of the E Flites are entirely satisfactory models up to say 56" span. At least that same unit can have grub screws fitted to adjust minutely the play at each end.

I cannot envisage paying E Flite prices for units that I then have to convery to servo operation after fine-tuning the fit of the parts - I did so on this one occasion because it was the easiest way out of where I had found myself.

I have taken a few photographs that I could put on my web site if anyone wishes.

If on the other hand E Flite decide to offer just the mechanisms without the drive system - as Robart do as an alternative to their pneumatic retracts - and at a significantly lower price, then they would be an attractive option. Especially if the frames were arranged to accept servos bolted on.

All of this and previous postings are of course only my opinion, others are free to disagree, and I have no commercial reasons whateever for making these observations.

Sorry if anyone thinks this long-winded, but I tried to make it complete in itself and as helpful as possible. I will put the same on the few other web sites where I have seen this subject raised.

Idris

I have found yet more lproblems, but the summary is too long to file here so I have made it available at http://www.fightbackwithfacts.com/re...ctor-problems/.

The same subjects have been discussed at

http://www.rcuniverse.com/forum/fb.asp?m=11184956

http://www.rcuniverse.com/forum/m_11...m.htm#11134586

http://www.rcuniverse.com/forum/m_10...m.htm#10549512

http://www.modelflying.co.uk/forums/...91&p=2#1218194