Mad Wax

Going in circles with choices here so I think a poll should help me out. Choices 6&7 are for owners, and should give a idea if the new hitec's suffer from frequent failures and how they compare to the Rhino's.

According to each official website, it appears the Hitec is more powerful!

5745 torque @ 6v- 250 oz
Rhino torque @ 6v- 205 oz

But on another site the Rhino's have 70oz more torque

Previous servos were dual hitec 705's, so I would want similar speed & power. This is for the Leopard.

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The warning with digital servos seem to conflict with RC usage (lots of opposing force etc)

Do not overload the servo Digital servos excel in their precision of movement and great holding power. In contrast to conventional servos with analogue electronics, commands are constantly passed to the motor of a digital servo. The servo attempts to move to the commanded position and maintain it under all circumstances. Where loads are severe, this results in very high current drain, and in the long-term this can result in overloading and even servo failure. For this reason the following points must be observed when using digital servos, to minimise the risk of failure and to ensure that the servo’s effective life is as long as possible:

Make full use of maximum servo travels If the travel of a control surface is excessive, do not correct it by reducing servo travel at the transmitter, but by re-connecting the linkage inward on the servo output arm (or outward at the horn). This exploits servo torque more effectively, and at the same time reduces the power required of the servo, and therefore its current drain.

Digital servos must never be stalled for a long period This is very important at the servo’s maximum travel (e.g. aircraft control surface at one end-point, model car brake / steering system), or when the servo is used for a non-proportional function (e.g. retracts, landing flaps may jam).

Avoid any situation in which the servo is constantly working against a force e.g. carburettor with spring-loaded throttle arm.

Note: 5-cell operation With a 5-cell battery the current drain is higher for a given load, and this significantly increases the risk of overload and failure. If you are using 5 cells, it is even more important to observe the above points!

jimbo1890

Mad Wax, Were you happy with the speed and power of the twin 705's? if you were stick with what you know. I had twin 705's in my old marder which worked well untill I stripped a gearbox. I then replaced with a single 755hb and the 705 went to throttle/brake. the steering isn't quite as good as it was before.

Mad Wax

Yeah dual 705's fast and torquey. I'm just wondering how they'll compare to a single digital servo (cost about the same) £25 for a 705, £50-£60 for single digital. Unless I'm mistaken a dual 705 has more torque than a rhino/5745- but less holding power.

thinking about it now- maybe buy a set of three 705's? Dual steering and throttle/brake servo? Good price overall, and lots of torque for brake. I have the PCM 3PK set, that allows analogue servos. But what about the fail safe? Does it still work with analogue servos? (battery and intererence fail safe)

Mad Wax

I've decided to go for analogue servos all round- with the lower current drain and longer battery times, especially warning regarding digital servos on throttle (spring) and also holding even if it's stalling..

So recommendations for analogue servos- 705 and 645- my previous setup. Any other higher torque than the 645?

chowderhead72

My Feedback: (4)

HITEC 805bb=343in/lbs@6v slow and noisy look at the TG5995 =digital,fast, titanium gears and 400+in/lbs all in a standard size case....I have two on order to replace a pair of 805s(slow and noisy) which replaced a pair of 5745s (epa set to %82 and still fried, POS) If I was starting over I would bite the bullet and buy the tonewega/oddified 50; $300 and you are done. I have bought:
2@5745s $85 each
2@805bb $40 each
2@5995tg robo $115 each
Total $480 just in steering servos and still 200in/lbs short of the tone/odd servo!

Mad Wax

Just went for dual 705's and a 645, pretty cheap £80 for all three from Als Hobbies.. Really not bashing hard or compo so don't need holding power of digital's, and prefer something a bit cheaper.

Just need new battery pack.

badz

My Feedback: (1)

I've fried 3 5745's and 2 805's and 1 705 so far all on a Hitec radio...I run a 5745 with a Airtronics and haven't ever had a problem with it. I've set the epa's down to 80% and they still fried on the Hitec setup. What worries me is over the winter I've built 4 airplanes and changed to Hitec's cause the LHS only was stocking Hitec flight packs....sure hope these Hitec's aren't prone to failures like the ones in my rc cars have been.

Mad Wax

Bump so Jeepfreak can post his poll choice

sasquatch1976

mad wax: Hitec 945MG. Still analogue as you like, but 13 kg (181 oz./in) vs. 9.6 kg (133 oz./in)