Can dig be 3 position? Drive, lock and coast?

[terrible]

Can the dig on the capra be set up in three positions? Drive for 4wd, coast for front wheel drive and lock for turning? Or is it meant to be 2 postilion four wheel drive and lock?

[ndnjames13]

I have done it on a ttx325 but I haven't figured out my dx5c yet

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[Brake Weight]

Yes. Been covered a lot in another thread but likely dozens of pages back now.

What transmitter are you using?

[Lanky]

3 position. 4wd, front wheel drive/ open rear, front wheel drive/ locked rear

[terrible]

Thanks guys. I'll do a little more searching. My kit was missing the little wedge adapter that mates to the splines on the servo and the other side of the servo arm. I happened to have an old kimbrough servo saver so I can make it work. But the ecopower servo I have is being a bit quirky.

The transmitter I'm using is a futaba 4PV.

[Panther6834]

Originally Posted by terrible

Thanks guys. I'll do a little more searching. My kit was missing the little wedge adapter that mates to the splines on the servo and the other side of the servo arm. I happened to have an old kimbrough servo saver so I can make it work. But the ecopower servo I have is being a bit quirky.

The transmitter I'm using is a futaba 4PV.

The 4PM is similar to my 7PX, and I did initially get the dig working as a 3-position. I used one of the DT knobs, setting the step to '100'. Unfortunately, due to "problems" with the Spektrum SX107 servo, the servo rarely centered properly so as to get the rear freewheeling position. For now, I've (temporarily) given up on it...but, once I determine a proper digital servo (the SX107 is analog), I'll give it another shot.

I've spoken with Futaba about this...specifically, with someone at Futaba who's into crawlers...and, it seems the best possibility would be an S.Bus/S.Bus2 servo, connected through the S.Bus/S.Bus2 port. I haven't yet had the time to check specs & dimensions, but the most likely possibilities are the following Futaba mini service m servos: BLS671SVi, BLS173SV, BLS173SVi, S3174SV & S3172SV.

~ More peace, love, laughter & kindness would make the world a MUCH better place

[terrible]

Well I got it to work but it isn't very repeatable. I assigned the switch on the grip (ps2 I think) to be a two position toggle. Then I assigned DT4 as trim for that channel with 5 step increments. I used 5 because it took way to long at lower increments to get the servo to travel far enough.

I can go from 4wd to rear lock very easy but getting the position in between can be a pain. Plan on taking it out today so we will see if the coast position is even really needed.

[sleepyhatch]

The dig can be 3 position. I feel like the Spektrum SX107 servo is too weak, coupled that with servo saver, it is too inconsistent as a 3 position. I have a FlySky GT3C hacked, with end points set up, I cannot get the dig to engage (locked rear).

I just ordered a Reefs 99, plan to eliminate the servo saver. That will give me more torque, and precision.

[mewalsh100]

I've got mine functioning on my DX4C. It can be a bit fickle though.

[Panther6834]

Originally Posted by sleepyhatch

The dig can be 3 position. I feel like the Spektrum SX107 servo is too weak, coupled that with servo saver, it is too inconsistent as a 3 position. I have a FlySky GT3C hacked, with end points set up, I cannot get the dig to engage (locked rear).

I just ordered a Reefs 99, plan to eliminate the servo saver. That will give me more torque, and precision.

You discovered exactly what I, and others, discovered. Good luck with the Reef's 99...others have had success with it, but, personally, I currently avoid Reef's. That's partly why I'm looking into Futaba mini servos...particularly S.Bus2 mini servos, which will be a LOT more accurate than analog servos, and even more accurate than typical digital servos.

In regards to the servo-saver, I could be wrong (still a crawler newb, but learning extremely quickly), but I don't think that's the real problem...it always returns the horn to the exact same spot (ie. the horn's position vs the servo's spline passion). Part of the problem, as many have realized, is that the SX107 is way too weak. I believe the other part of the equation is that the SX107 is an analog servo. For steering in crawlers, analog servos are probably fine...but, for a 3-position dig, 'precision' is required, which means digital servos. Just as with short course trucks, STs, truggys, buggies, VTA & USGT cars, and all other RC race vehicles, a 3-position dig should really be using a digital...NOT analog...servo.

Quickly touching on the torque matter, I have several TLR off-road vehicles, and something I learned early on is that Horizon Hobby's "recommended" servos are ALWAYS too weak for the intended application. Why, I can't say...but, for any Horizon Hobby vehicle, if you ever compare the "recommended" servo against the servo in the photos for the same vehicle, you will (almost) always find a more powerful servo being used in the 'photo' vehicles. If you ever talk to any of the drivers of those vehicles, again, you will always find them using servos that are more powerful than the "recommended" servo...and that includes Horizon Hobby's own 'team drivers'...as the "recommended" servos are always too weak, and almost always too slow.

~ More peace, love, laughter & kindness would make the world a MUCH better place

[terrible]

I'm looking into Futaba mini servos..

I've always heard that futaba "sandbags" their servos, in that, the servo can actually produce more torque than listed. I will 100% agree but, the price point on futaba is up there. I do love my 4pv and try to buy futaba when I can but I've had good luck with hitec for most applications.

A nice rigid mount for another brand of micro servo would be nice too. I've noticed quite a bit of flex out of the mount even with end points set. The servo can only do so much if what it's mounted to moves around.

[Panther6834]

Originally Posted by terrible

I've always heard that futaba "sandbags" their servos, in that, the servo can actually produce more torque than listed. I will 100% agree but, the price point on futaba is up there. I do love my 4pv and try to buy futaba when I can but I've had good luck with hitec for most applications.

A nice rigid mount for another brand of micro servo would be nice too. I've noticed quite a bit of flex out of the mount even with end points set. The servo can only do so much if what it's mounted to moves around.

There are machined servo mounts available, for the steering servo, as well as the dig servo. I'm drawing a blank on who's selling the "package" (both mounts), but I'm sure someone will chime in with that answer. As for servos in general, Hitec had been my 'go-to' for a while. While I have one Savox, a couple of Spektrums, and a few Futabas (soon to be more, once I've built this second Capra), most of my vehicles are running Hitec.

There was a point I was considering switching to Savox...I even created a thread, raising that very question...but, the consensus was to stick with Hitec. The primary reason I'll be running Futaba in the 2nd Capra (steering), and looking into Futaba for the 1st & 3rd (dig only) is because of the extreme accuracy when connected via the S.Bus/S.Bus2 port.

As accurate as T-FHSS SR mode is (compared to T-FHSS), the S.Bus/S.Bus2 is more accurate. Speed-wise, both are equally 'fast'...but, Futaba does now have something faster - their new FASSTest technology, although, that's specific to their air transmitters.



~ More peace, love, laughter & kindness would make the world a MUCH better place

[turboturro88]

i set mine up for this using the stock controller. only problem is it goes from 4x4 to rear locked skipping over the free wheel unless i start at rear lock then it will go into free wheel then 4x4 mode.

[sleepyhatch]

SSD makes the servo mount package, steering and dig servo mounts. I bought it from Amain, they are great, and cheap too.

https://www.amainhobbies.com/ssd-rc-...00394/p1155898

My Reefs 99 will be here Friday, will swap out the Spektrum SX107 this weekend.

[Panther6834]

Originally Posted by turboturro88

i set mine up for this using the stock controller. only problem is it goes from 4x4 to rear locked skipping over the free wheel unless i start at rear lock then it will go into free wheel then 4x4 mode.

If you start at rear locked, switch to freewheeling, then switch to 4WD, what happens if you two to switch it back to rear freewheeling? Does it go to freewheeling? Or, does it go immediately to locked rear?

~ More peace, love, laughter & kindness would make the world a MUCH better place

[Still Bill]

Originally Posted by turboturro88

i set mine up for this using the stock controller. only problem is it goes from 4x4 to rear locked skipping over the free wheel unless i start at rear lock then it will go into free wheel then 4x4 mode.

Actually not a problem. That is how mine works using Spektrum Rugged and Reefs 99 micro servo. Such switching is referred to as "Cyclic" on the Rugged.

[turboturro88]

Originally Posted by Panther6834

If you start at rear locked, switch to freewheeling, then switch to 4WD, what happens if you two to switch it back to rear freewheeling? Does it go to freewheeling? Or, does it go immediately to locked rear?

~ More peace, love, laughter & kindness would make the world a MUCH better place

it would go back into locked.

[Panther6834]

Originally Posted by turboturro88

it would go back into locked.

In other words, you don't have the '3-position' set up properly...or, you're having the exact same problem that most of us have had when trying to get 3-position to work with the SX107, which brings me right back to what I said earlier about analog vs digital servos.

I'm not trying to put Horizon Hobby, it any of their brands, down. As I've explained several times, in multiple threads, and in multiple forums, Horizon Hobby is known for "recommending" servos that are considerably less powerful than what should truly be needed. Additionally, there's the matter of analog servos being less accurate than digital servos. While I can see using analog servos for steering on a crawler, i would NEVER out an analog servo into one of my race vehicles. Likewise, one shouldn't be used in a 3-position dig...2-position, yes, but 3-position, no.

~ More peace, love, laughter & kindness would make the world a MUCH better place

[TheLetterJ]

I think part of the difficulty of setting it up as a 3 position is the flex of the dig servo mount. It may consistently hold its settings when pulling, but when it pushes (or vice versa), the servo kinda leans the opposite way and the same degree of rotation at the servo will have the shift rod in a different spot. With such a narrow range between the 3 positions, that little bit of flex can cause a lot of headaches.

I don't know if either will 100% fix that issue (though they certainly couldn't hurt) but SSD makes an aluminum servo mount set, and there's at least one 3d printed skid that has the dig servo mounts incorporated into the skid.

[aconsola]

I built a Capra over the last couple days. I got the Dig set up to be 3 position using a 7px transmitter and a generic mg90s micro servo.



I used a plain servo horn with the post mounted far enough out that it was nearly hitting the far side of the yoke when the arm was perpendicular to the servo.

I found that having the post centered when perpendicular caused the linkage to bind on the way towards locked rear as the arc of the horn travel was pulling the linkage towards the servo.


I used dt4 and started by setting the center point with the sub trim function. Then I set it to 100 step to make it 3-position and used end point to adjust the travel independently in each direction. It took some tweaking, but now it consistently moves between all 3 positions as expected.