Traxxas T-Lock TRA5697 for TRX-4 - Guide

[Ambis]

I found only one topic about the TRA 5697 T-Lock module (for summit).

The module allows you to control two servos from one channel.

• Ch position -100 is all servos "off"
• Ch position 0 is one servo "on"
• Ch position +100 is both servos "on"

The problem with TRX-4 is: One servo is the other way around than what they are in the Summit. This means, by using the T-lock with TRX-4 as it is supposed to be used, you get a really funky setup:

• Ch position -100 front is locked
• Ch position 0 both are locked
• Ch position +100 rear is locked

OR if you switch the servos:

• Ch position -100 rear is locked
• Ch position 0 both are unlocked
• Ch position +100 front is locked

And that is what you do not want. You'll be missing full lock and full open with the stock T-Lock setup which ever way you connect the servos.

What I did:

With my Futaba 4PL (4 fully programmable channels), I use one channel (ch3) for the rear lock ONLY. This allows me to have one button that controls the rear diff only. I can also set the End points for the servo, which maybe means it won't burn out so quickly.

In ch4 I have the T-Lock system which is hooked to the front lock AND the 2-speed. Now I get:

• Ch position -100 front is open and slow gear
• Ch position 0 front is locked and slow gear
• Ch position +100 front is locked and fast gear

This means whenever I run with fast gear, my front diff is locked. But I am willing to live with that, since I get to run my Futaba radio with front EPA's etc (and I can also easily drive with one hand which is hard with the TQi).

If someone were to offer this piece (TRA8240) at shapeways where the other servo mount would be flipped, then the T-lock would work out of the box (with open, one locked, both locked functionality).

Hope this helps.

 

[sunsetkid]

Hi there. I use a 4PL and encountered the same issue.
I suggest: a simple servo signal reverser costing a few dollars.
You connect the servos to the tra5697 where:

Ch position -100 rear is locked
Ch position 0 both are unlocked
Ch position +100 front is locked

And you insert the signal reverse between 5697 and the front diff lock servo.
This solves the issue without having to reverse the servo physically

 

[Ambis]

Wow! I had no idea those even existed! gotta find myself one of those.

 

[sunsetkid]

Yes they are available!
I got mine off Taobao in china.

The exact same one is available on Aliexpress.
Less than usd 2 shipped.
Shipping time for aliexpress is notoriously slow though

https://m.aliexpress.com/s/item/32760510378.html?spm=a2g0n.search-cache.0.0.3d2c41cawnJzDD

 

[Ambis]

Ordered a bunch of Turnigies from Hobby K. Nice and very short.

 

[sunsetkid]

hobbyking reverser is cheap too. shipping is better as they're based in HK.
i used to be a longtime customer of theirs, from the time they were called united hobbies 15 years back. but in recent years, i just buy direct from Taobao China. basically almost everything i can get off HK, its available at a better price off Taobao. only thing is you need to learn how to read Chinese.

 

[Ambis]

hobbyking reverser is cheap too. shipping is better as they're based in HK.
i used to be a longtime customer of theirs, from the time they were called united hobbies 15 years back. but in recent years, i just buy direct from Taobao China. basically almost everything i can get off HK, its available at a better price off Taobao. only thing is you need to learn how to read Chinese.

Thank you for this information. I will now start learning to read Chinese to save a few bucks.

 

[Greatscott]

This is funny, I just ran into this issue last night when I was trying to install my DX5R.

The servo reverser is the answer to get it to work like the TQi. With the DX5R, the center position was with both locked, and I could unlock the front front while keeping the back locked, or the other way around, but not both unlocked. I am thinking about running it this way and seeing if it isn't actually useful.

 

[fr8cture]

Front locked and high gear......why?

 

[clm]

Peppy from Star Fox: So it can "Do a barrel roll!":ror:

 

[Ambis]

Front locked and high gear......why?

Because that is the only reasonable setup you can have with the T-Lock without a servo signal reverser. And the only use I've had for the faster gear is to bash around and flip the truck.

There's other ways to set it up, but this has the least drawbacks.

Going to have a spin this afternoon. Looking forward to being able to lock the rear only (makes more sense to me than locking the front).

 

[sunsetkid]

Thank you for this information. I will now start learning to read Chinese to save a few bucks.

Ahah, it will cost you much more in time and money to learn Chinese than what you get to save..

 

[sunsetkid]

This is funny, I just ran into this issue last night when I was trying to install my DX5R.

The servo reverser is the answer to get it to work like the TQi. With the DX5R, the center position was with both locked, and I could unlock the front front while keeping the back locked, or the other way around, but not both unlocked. I am thinking about running it this way and seeing if it isn't actually useful.

You get this scenario when your front servo goes into the B port of the 5697 and the rear goes into the A port.

To get it working like the TQi, you plug the rear servo into the B port and you place the reverser between the A port and the front servo.


Alternatively, just get a hacked flysky gt3c for 8ch or the expensive upcoming futaba 7px. Won't even need a 5697 or reverser!

 

[CODYBOY]

You get this scenario when your front servo goes into the B port of the 5697 and the rear goes into the A port.

To get it working like the TQi, you plug the rear servo into the B port and you place the reverser between the A port and the front servo.


Alternatively, just get a hacked flysky gt3c for 8ch or the expensive upcoming futaba 7px. Won't even need a 5697 or reverser![/QUOTE

I have been running the hacked GT3C for several years, so no brainer for me."thumbsup"
Ernie

 

[Ambis]

Yesterday I got the signal reversers in the mail and put one in.

I put it between the T-Lock and the front diff, which now gives me (with 4PL):

Rear lock: Engaged - Open
Front lock: Engaged - Open - 2Speed 2nd gear

Which means I have full control over rear lock (with EPA's to keep servo happy) - which is in my opinion the most useful lock to control.

Then, when needed, I can lock the front also, but need to be wary which way I run the switch because I might engage 2Speed 2nd gear.

But the great thing now is that when running 2Speed 2nd gear, I have an open front diff (good for axle shafts!) but I can still control the rear lock!

And BTW, this thread was for 4-channel radios and using the T-Lock. But thanks for mentioning the flysky radio.

 

[RickM]

Ok. So I ordered a t-lock and servo reverser, but I have a question. I’m going to use a Futaba 4pl, and I was wondering if the setu0 mentioned above truly works like the stock setup on the diffs or am I going to be giving up something?

 

[RickM]

Well. I got my t-lock and reverser and set everything up the way it was mentioned above, but I think I fried my little servos trying to figure this out. Using the Futaba 4pl, I had very little trouble setting up channel 3 as my transmission, but on channel 4 I was having problems, and may have fried my servos. Can someone post up how they setup servo 4. In other words, what were the end points used etc. My setup is as follows. I am using DT4 as a 3 pos switch. I have the channel setup normal. Position is at zero, sub trim is at 0 I have the end points as EPA U 30, and EPA D at 61. I could never get them to work like they are supposed to. Any help would be appreciated.

 

[BashNSlash]

Hi there. I use a 4PL and encountered the same issue.
I suggest: a simple servo signal reverser costing a few dollars.
You connect the servos to the tra5697 where:

Ch position -100 rear is locked
Ch position 0 both are unlocked
Ch position +100 front is locked

And you insert the signal reverse between 5697 and the front diff lock servo.
This solves the issue without having to reverse the servo physically

I got my 5697 and just have to wait for the servo reverser to arrive before I set things up.

But how does one adjust the EPA's with this configuration? Can they even be adjusted?

 

[BashNSlash]

Ok, I picked up both the 5697 and a servo reverser and couldn't get it to work right. So I tried the servo reverser on its own and it worked perfectly.

This is the one I used. Note that it's a y harness style.

This is way easier than using the 5697.

On my flysky fs-gt5, I was also able to adjust the endpoints to make both servos happy yet functional.

Sent from my SM-N950W using Tapatalk

 

[rcracer78@gmail.com]

Sorry to resurrect this post but I’m about to do this with my Futaba 4PKSR and R614FS. Don’t laugh...she’s an oldie but goodie. Much prettier & comfortable in the hand, compared to Tqi too. Anyway, I just need a little guidance before taking on this task so any advice would be greatly appreciated "thumbsup"

My question is...

Can I do this successfully with a y-harness type servo reverser?(like the last post)
OR
Do I still need T-lock TRA5697 and reg or y-harness type servo reverser?