Hitec HS-815BB Has anyone used one before

[fats_nz]

I have found this hitec winch Hitec HS-815BB

I want to use a winch arm for my impending 10r because they are faster than a drum. Does anyone know if this winch is powerful enough for the sails.

My mast will be 2meters tall and I havn't worked out just how long the boom will be but im sure it will carry a significant amount of sail area.

any suggestions?

Smartwinch to exspensive
hitec drum to slow
what to use???

[Brian Wa]

I can't say how it will perform on a 10R yacht but on my IOM one metre boat it works fine on the No 2 and No 3 rigs, I haven't built the light airs No 1 rig as yet.

Brian

[thorsail]

hey fats
you might be on the edge there - 815BBs have been a standard in the
Soling 1 Meter boats - those are 10+ pound boats with a total of 600 sq.
inches of sail area .

[1967250s]

Lots of people use the 815bb, very powerful and reliable. For only 600 squares, it should be plenty. You can go to servocity.com to compare to others, the geared setups are super-powerful. I have an 815bb with a 5-1 ratio on my N12 with 1500 sq.in..

[Brian Wa]

You can run the 815BB on 5 cells and get more torque out of it.
Check the manufacturers specifications for details.


Brian

[Brian Wa]

I have an 815bb with a 5-1 ratio on my N12 with 1500 sq.in..

Could you please explian how you achieve the 5:1 ratio. A sketch or photo would help to clarify things.

Brian

[DanL]

Really don't think the 815BB will come close to being adequate.
Even if the 815BB has the torque, it will suck a lot of current to maintain its arm position and will likely be overpowered in gusts, either blowing out the servo or the fuse. It's an arm servo with 140 deg rotation and will require a long arm that really cuts the force it can deliver (over 10" center-to-tip by my estimation).
I tried an 815BB on a Soling 50 (about 1000 sq-inch sail area) and blew fuses (blew a servo before I used a fuse), had glitches, etc. Tested the amp draw under load and it was peaking very high (don't remember the numbers, but definitely over the 815BB rating). Your sail area will be about 1700 sq in., almost double that on my Soling 50. That's a lot to pull around.
I also used the 815BB on a 7ft square rigger brig. Sail area per mast (one servo per mast) is approx. 4+ sq ft (576+ sq in) and the 815BB's were just barely making it. Wouldn't pull the yards around against a strong wind (12mph) and would overload in a gust. You might consider a 785BB drum winch, but with a bigger drum to increase speed of line pull.
I think these approximate calculations are good:
For the 815BB servo: Assume you need to pull the sheet 24" (you will probably need more). At 140 deg arm rotation, the servo arm would need a length of over 10 inches to get that length of pull. The torque of the 815BB at 6V is 343 oz-in. The "delivered" force would be 343 oz-in/10" arm = 34 oz. of force. The speed would be 0.38 sec for full travel of 140deg (from spec sheet).
For the 785BB servo: Same total pull assumed, 24". At 1260 deg rotation (3.5 turns), the drum radius would need to be only 1.1 inches to pull the 24" of line. The torque of the 785BB at 6V is 183 oz-in. The "delivered" force would be 183 oz-in/1.1"= 166 oz. of force, about 5 times more than the 815BB. The speed would be (from the specs) 1.4 sec x 3.5 rotations = 4.9 sec. Too slow for you, but likely enough power.
But now increase the 785BB drum radius to, say, 3 inches to get more line speed. The force available would be 183 oz-in/3"= 61 oz., nearly double that of the 815BB with the 10" arm, and only 1.3 rotations rather than 3.5 rotations would be needed. The speed would be improved to (calculated from 1.4sec/360deg per the specs) 1.3 rotations x 1.4 sec/rotation = 1.8 seconds for the required travel (about 3x faster than with the smaller drum).

Now you have an option with double the force of the 815BB, but still at 1.8 sec vs the faster 0.38 seconds of the 815BB. And I'm not sure that even double the force will do it for your sail area.
Also, look at these servo/gearboxes:
http://www.servocity.com/html/spg400a_top_mount.html
Plenty of power for about $100 range, super quality (have one in my Soling 50 now), but weight might be an issue for you. Speed is dependent on gear ratio you pick.
I'm guessing you need a servo rated at least 1000 oz-in for your sail area.

Hope all this helps some. Also hope somebody out there can add/improve the recommendation.

[Dick L.]

Used the 815BB on my 1100 sq. inch 1 Meter trimaran and needed it because it was "QUICK" - and could handle the load. The Hitec drum is S-L-O-W in comparison (used on the Laser I believe) and if you can plan ahead it's fine. On the multi, there is no such thing as planning ahead - it all happens "NOW" and one can only react.

I am runnig a "Y" harness and have not had any power loss or battery issues - but use 5 NiCads for receiver/servo power.

It was also used in my F-48 multihull (48 inches long with 1400 sq. inches of sail area) and again no problem. With that said - I did change down in rig sizes so the big sail area was in light winds. As winds picked up sail area decreased so never seemed to have over-loaded the thing. In fact, just wish they (ServoHut) would modify one for 1-3 turns. I would go for it in a minute.

RMG is pretty much the only other option. Email Mark Gee (AMYA Class secretary) and he should be able to give you an idea of what they are using. It may be the RMG series - don't know.

[DanL]

Dick L
How long is your servo arm on the 815BB in the 1M trimaran?

[A.B.]

Can the 815 be run through the y harness and use 6 AA batteries? For a grand total of 7.4 volts?

[DanL]

You can jack up the voltage, but there is a limit to the load the motor inside the servo will take. I think they rate it at a max. of 2 amps. When I used it in the Soling 50 with about 1000 sq in of sail, it would blow three amp fuses.
Seems others got better output from the 815BB than I did, but I just don't think it will handle the roughly 1700 sq in of sail that fats nz is looking at.

Note that an 805BB, same guts as an 815BB and same power output, can be ordered with a 180 deg rotation option for the same price as the 815 (which has only 140 deg rotation). That gives you over 25% more rotation than the 815, allowing use of a shorter arm and a bit more power transfer.

[Dick L.]

Dick L
How long is your servo arm on the 815BB in the 1M trimaran?


Total of 4 inches in length, and a double arm - one side controls mainsheet and other side of arm controls jib in a "classic" dual sheeting arrangment.

Unfortunately it is too wide for my main hull, thus sticks out on each side - It follows similar to the red 1 Meter multihull in photo (courtesy of Jack Ronda - Washington) which is a scaled down Mini40 "PULSE" design. Doesn't "look" great above deck, but works .

[fats_nz]

ok so the arm with the big winch may be overloaded on my boat. I could use the drum winch. Shorten the travel by adjusting the End Point on my transmitter and attach the sheets to the boom closer to the mast i.e. less moment arm. This could give me a balance of speed and torque.

I do like the smartwinch and have one on my other boat but this boat will just be a "hack" so im not to concerned about having the best and most expensive gear.

Thanks for all your input its appreciated

[robert harik]

A large variable is the friction on the sheets as they and pass through and change direction at the ends of the winch arm and fairleads. A huge amount of power can be lost to heat and actually removing material from the arm,sheets and fairleads. Bearing pulleys, work really well,teflon or nylon bushings in the winch arm are much lower friction too. Spraying the sheets with teflon lube works great also.

There is a simple mod to make the 815 move through 180 so you dont need as long an arm. When you set up the winch make sure that the arm is parallel to the centerline of the boat when close hauled so the arm the sheet sees is as short as possible and the servo will be able to hold its position easier.

[larrykin]

Hi Fats NZ,

My 2 cents worth. My biggest boat is an AU Class. LOA 1.7m, boom 750 mm, mast 2.2m with sail area approx 1.4 sq m or 2000 sq. inch. (It's not for racing as sails are illegal). Here's a pic of the boat when it just had the sails fitted -

http://i231.photobucket.com/albums/ee243/larrykin/AU%20Class%20Build/P1010652.jpg

I talked to Rob at RMG Sailwinch and he explained to me that the only winch that would work in my AU boat was a 380EH Sailwinch Servo. Others would stall and burn-out. The specs say it has a Stall Torque of 29.9 kg/cm. The same drum winch is fitted to the French boat - pic below. As for speed; when I'm sailing the winch pulls 'just right' to tack and keep control of the boat in strong winds.

On one of my 1m boats I have a HiTec HS-765HB fitted with 11 kg/cm torque.
The HiTec is 'overkill' for the 1m boat and cost $AU69.

The RMG winch cost $AU280. RMG does sell smaller smart winches, as you probably know. But they're still about $AU240. So how much money are you saving with the HS-815BB considering that its specs don't seem to match your boat?

I've been in the position sailing a 1m boat, where the wind suddenly picked up and the winch had no way of getting the boat turned round back to shore. Kept racing downwind and finally smashing onto the rocks. Lucky I could retrieve the wrecked boat. From this lesson I now go the safe route and have winches strong enough to haul the sails. Cheaper than losing a boat. Or like building a Porsche and fitting it with a VW motor.

Larry L.

[fats_nz]

Hi Larry,

Thats a very nice boat you have.

The prices in NZ dollars is
280RMG $290ish
Hitec Drum $90 ex USA
Hitec BB Arm winch $90 ex USA.

I have seen plenty of people use the hitec drum winch on EC12's which i think would not be a lot smaller than my new boat. They don't seen to mind it and one swears by them.

As you know there is a significant price difference. Maybe I should look at building my own, similar to the RMG but without the clever electronics Rob puts in his winches?

[CaptainBit]

My best advise would be to "bite the bullet " and buy yourself another RMG winch.
Not only would you then have no question as to whether it will do the job but you will also have a spare for your other boats.

A WIN/WIN solution....dadahhh. :D

[fats_nz]

Gidday Ian,

Hope you are well.

Yes that could be the inevitable but it is a good idea to research the options first. Is there anything else out there worth looking into?