da Rock

The problem a lot of us seem to be having is the weakness of the Wingspans. That was mentioned when I emailed them about sending my 1st pair back, and I've recently received a response that says they have a 99% belief the software update should solve the problem.

Keep in mind when testing the gear in the shop that the shop environment doesn't include the air drag that adds to the workload retracts face when lowering the gear in flight. Hopefully the software change ups the power at 4.8volts. If they hope to compete at all with Lado, they really do need to easily cycle struts and ARF wheels in flight at 4.8V. There are going to be lots of modelers who not only put articulated struts on their models but include scale doors like on the Hellcat. Those are attached to the struts and add both weight and drag.

Heck, the full scale Corsair pilots used to unlock the gear and let it hang out as dive brakes. The doors on the Corsair were not huge, the ones that were attached to the struts, but they added sufficient drag to slow the plane at speed.


BTW, look at the lower right of the picture of the Hellcat in the museum.

flutter caused it

The recent Model Airplane News magazine (Febuary edition) has additional information concerning the expected release of Robarts' new electric retracts. The information given state that they will be available in either 85 or 90 degree versions, with no mention about availability of a rotating set.

frets24

My Feedback: (15)

This should be interesting....Just received a set of the 85* high speed (8-11 sec) E-tracts from WingSpan. They're intended for a 70'' Zero that won't be ready to maiden until late spring to mid summer. I may have jumped the gun on these though I really need them at the very beginning of the wing mods in order to do the fitting and mounting reinforcements....Catch-22 I suppose.

Will be following along here for the latest and the greatest......(emphasis on the greatest, got burned on some early lados)

da Rock

OK, both sets showed up last night in one package. I had time enough to test the returned set on the Hellcat. They seem to operate about twice as fast as they did (without wire/wheels) before I sent them back. I began reinstalling them in the wing but haven't gotten much of that done. Will get back when there is something worth mention.

edit (Fri 9th)........ Today at the field they wouldn't lift the gear the Lados lifted easily. Think tonight I'll try running them from their own battery on shorter wires.

FWIW, I'd sent the weak set back to Wingspan around Nov20 and got them back here yesterday, Dec7. Not bad.

drube

Sounds good so far!

irocbsa

My Feedback: (12)

Mine should arrive back here today. I hope I have the same results.

da Rock

Bad results today.

They couldn't extend the gear with the plane upside down. The Lado's had no problems with that gear and the same wiring with an 800 mAh NiCd pack that runs the whole model at 4.8V (what failed to work the 1st try and got the WingSpans shipped back). However, it's quite possible the 1300 mAh 6V NiMH pack can't provide the juice with the regular wiring.

Tonight I try providing the WingSpans their own 7.4V LiPo pack right there in the wing with them (on a very short connection).

drube

Bummer, was hoping for good news.

What kind ofpower does WS recommend?

da Rock

OK, I tried giving them their own dedicated pack. Used a 6V and put it right in the wing with them. No long connection and the same voltage RBean reported drive his Wingspans. No joy. They move out about an inch and slow to a stop.

Time to email WingSpan again. Something isn't right.

irocbsa

My Feedback: (12)

No, it certainly isn't. I'm sorry to hear about your troubles Rock. I got mine back yesterday from Wingspan and they are functioning well on a 4.8V 1700Mah pack. I am using ESM 4" wheels and Lado struts. All in all, it's a pretty heavy load for them to lift.

I will run the retracts on 6V in the plane with a pack dedicated specifically to the retracts. I'm going to keep cycling them and see how they hold up.

drube

Iroc, so youhave no problems with them? Have you had a chance to fly with them yet?

da Rock

Good to know everybody isn't having the trouble mine have given. That means they'll have some that work to swap for mine that don't.

One thing I noticed with mine. When they worked the couple of times they did, they speed up after moving about an inch and then slow down to the same pace for the last inch. They were fast through the middle of the arc. Odd, you'd think they'd go at constant speed the entire arc.

I'm using the OEM wheels and Robart struts, and the Lados didn't break a sweat moving them in or out. And the swing was at a constant screw jack speed. I'm looking forward to the faster speed. When I get some that work that is.

da Rock

I've not seen anything in the advertising about special power requirements HOWEVER..... I just received the following from Michael. I have to admit it's a bit surprising, but here it is.

da Rock

This is surprising. But we'll see in a very short while.

Needless to say, that's a huge battery capacity even if it's LiPo. If simply using high voltage and such a BIG battery works, it'll be interesting to see how much capacity those things use up. Hopefully a 25C or greater LiPo of smaller capacity would work. It will be much better if we don't have to carry so much weight. We're talking about 4-5 ounces for battery weight with a LiPo.

Competitively, air retracts carry a significant weight penalty over most electrics, so going from air to electric you'll have weight to spare. But the Lados worked happily on the RX battery and take no extra anything.

But actual testing (after breakfast) should show more about this.

da Rock

Turns out I won't be testing the suggested battery setup. Although I have a number of electrics and LiPos to fly them with, I don't have any 2000-3000 mAh 7.4V packs. MOF, I don't have any two cell packs anywhere close to that large.

irocbsa

My Feedback: (12)

drube, at this point I am not having any issues. Of course, I have had issues of my own and had to send them back twice to get them working right. I did switch to a 6V 2200Mah pack.

drube

Thanks, so WS is recomending a 6v 3000 mah battery... I wonder how many flights you can get with that size battery? I don't mind adding a battery but I would like to get at least 4 or 5 flights in before recharge. I'm with youRock, whatkind of current draw willthese have?

da Rock

It's a puzzle right now that's in the process of being solved. I've got the LiPo on the smart charger. It came off that charger immediately before being used to cycle the gear 5 times in different attitudes. So it was full when it was asked to work the gear. It went back on immediately after that work. We'll see what that took for capacity and then make some wild a** guesses as to what effect aero-drag would have and what impact using a 10C pack instead of 30C would be and if there need be a more appropriately sized pack and.... on and on and on.

da Rock

Is that 2200 mAh pack a NiCd? The 1300mAh NiMH 6V packs I bought to do the job, couldn't do it. NiCd of course can deal with higher loads.

da Rock

OK, it appears the capacity of the dedicated pack is not an issue other than it's affect on the ability of the pack to provide for load.

It appears that LiPo packs dedicated to the retracts don't have to be large capacity if they have a decent C rating. I'm going to borrow something in the 1000-1500 mAh range to do a 2nd test before flying. They'll probably be at least 20C nowadays.

I'm not going to rely on NiMH for the retracts, either dedicated or shared with the RX etc. They most certainly need to be considerably larger capacity than I'd have used just to run the model otherwise.

I don't have any NiCds that suit any situation with these retracts. But from the looks of it, for a dedicated pack for the retracts, I'd go with 6 cells and more capacity than I've yet seen anywhere.

irocbsa

My Feedback: (12)

It's a NiMH pack. 6V, 2200 Mah.

da Rock

I've been buying batteries from HangTime for years. He's a good source of information about batteries and makes good quality packs. I'm don't usually use NiMH packs for flying models (great for TXs however) so don't have direct experience with that chemistry so decided to research a bit in HangTime's website. http://www.hangtimes.com/giantrxpacks.html

The 1300 mAh 5 cell NiMH I tested (and that failed to drive the WingSpan retracts) weighs 4.3 oz. It's impedence and 6V wasn't enough to run the WingSpans as mentioned. So I figured to see what going to 2200 mAh in NiMH would do for me. I know that size works well for others, but how much weight will the model have to carry compared to the 2.3 ounces my test LiPo that worked OK added.

Well, I couldn't find any 2200 mAh NiMH for sale from my usual (3) sources. So I looked at both 2000 and 2400 mAh packs. While I was looking at 5 cell packs, I decided to also look at 6 cell ones as WingSpan suggests the higher the voltage the better. And since my "puny" little 1300 mAh 10C LiPo drove the WingSpans decently enough at 7.4V and used almost no capacity doing it, I figured the 6 cell NiMH made good sense.

My little LiPo weighs 2.3 oz and does the job with no sweat and almost no capacity drain. Apparently the LiPo voltage and impedence is all that's needed to get the job done and capacity is only needed for NiMH in order to get around poor impedence from that chemistry. As an aside, HangTime lists impedence and it appears there is a fairly wide range found over different size NiMH and it's not predictable by size. So.........

It looks to me like using NiMH burdens the model with a bunch of weight that's only needed to make up for poor performance under load. The 2400 mAh packs I could find appear to weight around 11 ounces. The 1900 mAh packs are 10oz. It looks like to get acceptable performance out of NiMH requires over a half pound (close to 3/4lb) of dead weight. (I feel an extra battery just for the retracts really is dead weight considering the Lado's don't require their own power to do the job.)

When I get the time, I'm going to test a couple of "small" NiCd packs. If I can find them. I figure a 6 cell NiCd pack of around 600 mAh just might work as NiCd provides voltage lots better than NiMH does.

In the meantime, I figure to go with LiPo and only add about 3 ounces of dead weight instead of over a half pound.

flutter caused it

Sorry to leave everone hanging on the install. I've just completed school yesterday, and have my pinning ceremony tonight where I will receive my RN degree (after 3 1/2 yrs). I have also decided to return my WingSpans to Mike, as he states that he will install a "sofware" update to help aleviate some cycling problems that come from the needed wiring extemsions. I was also told to replace my 4.8 volt pack with at least a 5 cell, with a capacity of 2400mAh. Like DaRock, my Lados have worked fine with my 4.8 volt 1800mAh pack, and anything more is simply adding weight, but what are we to do??. I have come so far with the install, that I hate to admite defeat, so I will return the WingSpans for the update, and hope for the update to cure some of the problems, but I must admit that I have some reservations. It almost seems as if what is needed is a stronger motor, or a finer pitch jack screw to help overcome the cycling issues.
Iroc, is your WingSpan retracts of the "rotating" type, or the standard fare? I did see it mentioned anywhere.

irocbsa

My Feedback: (12)

Hi guys, I have both the standard and the rotating set. I too apologize for the delay in updating. Thus far, I have had good luck with the retracts after they arrived back from Wingspan. Michael has been very prompt in addressing the problems and I'm hoping that all the feedback he's getting on real and potential issues will result in a reliable product that fills a huge gap in the market.

I've been using 6V packs and haven't had cycling issues yet. The software update seems to have made a difference as I had issues just like you are talking about regarding the use of y-harnesses and extensions. Both my rotating and standard units are lifting Lado struts and ESM metal wheels.

da Rock

Man, it'd be good to hear from someone who used 6V but got it from NiCds.

It really appears NiMH has to have 2200 mAh capacity for 6V to work. It'd be nice to see what capacity was needed for NiCds to work.

It really appears that LiPo can be really small, at least compared to NiMH, and work great.