build problem - servo cannot reach needed points

[gkatz 49]

hi all;

building my neo scorcher all went well until electronics part.

when mounting the servo to the bottom screws (1) i noticed that the part that needs to be attached to the actual streering (2) does not reach the needed contact points (3)

I am missing a centimiter give or take.

is this something that one usually encounter? is this a servo height issue? should I create new holes in the plastic chasis for (1) to pass in?

any siggestions?

thanks

[Twinfan 1243]

If you're building as per the kit then you shouldn't have an issue like that.  Any standard or low profile size servo should work fine.

Are you using the standard servo saver and arm?  And which servo do you have?

[gkatz 49]

47 minutes ago, Twinfan said:

If you're building as per the kit then you shouldn't have an issue like that.  Any standard or low profile size servo should work fine.

Are you using the standard servo saver and arm?  And which servo do you have?

hoe this vid shows better my problem:

https://photos.app.goo.gl/zmvAiSe8YT6muCTN8

your help is appreciated

[Twinfan 1243]

Your problem appears to be the blue aluminium servo arm.  The official Hop-Up is #54799:

https://www.thercracer.com/2021/03/54799-tamiya-tt-02-high-torque-servo.html

You seem to be using something else?

[gkatz 49]

hi

the arm is not a formal hopup but I dont believe its that. even with the plastic one form the kit I ahve the same problem

the arm is just too low and not alligned well with where it needs to conenct to. its really wierd...

so instead of having a relatively straigh line between both points i have a relatively big angle which cant really connect...

surely i did something wrong but I cant seem to undertstand what

[Twinfan 1243]

I think it's the arm from what I can see.  If you use the standard servo saver and plastic arm, the arm will be a lot further forward towards the front of the car.  It will stick out from the servo and allow a straight link to the steering arms.

Your issue is that the aluminium arm is too close to the servo body - it does not stick out far enough.  That is why the Hop-Up uses a thick/deep 5100 servo saver and arm on top, like the standard parts.

[gkatz 49]

ok will try the kit parts

[gkatz 49]

2 hours ago, Twinfan said:

I think it's the arm from what I can see.  If you use the standard servo saver and plastic arm, the arm will be a lot further forward towards the front of the car.  It will stick out from the servo and allow a straight link to the steering arms.

Your issue is that the aluminium arm is too close to the servo body - it does not stick out far enough.  That is why the Hop-Up uses a thick/deep 5100 servo saver and arm on top, like the standard parts.

yep you were spot on - thanks for the help

[Twinfan 1243]

No problem, happy to give something back to the forum after taking a lot over the last 12 months!  

[OoALEJOoO 3127]

@gkatz I don't think you did anything wrong . The issue seems to be that the servo you are using is a bit short. When using a standard servo, the servo link D6 will pretty much be orthogonal to the steering link A7. Some servos are shorter, resulting in D6 being in an angle that cannot reach A7. I've experienced this before with some servos on TT-02B kits. Looking at your video, it seems that this is the case with the servo you are using. Other than getting another servo, some possible solutions are:

• Try connecting D6 to the front side of the servo horn instead of the back. Maybe this will make it be orthogonal and reach better.
• Put spacers or shims between your servo and parts A3 to push it forward.
• Use part P6 (normally unused) as a servo link instead of D6. This part has a curvature that makes it reach A7 better. You will need to use a stepscrew to connect P6 to A7. To connect D6 to the servo horn you'll need a M3 screw + 3mm ID tube + locknut to connect to your servo horn (you can go without the tube, just make sure you don't overtighten the nut against the screw).
• Get a turnbuckle + connectors like in the above picture from The RC Racer.

Good luck!