Eight t 2.0 rtr truggy throttle servo

[Losi-038]

The 2 times I've been to a local track I have lost my throttle after a jump I have replaced servo. works great than hit jump and blown again can anyone help? Thanks

[mottman]

I type this, really hopeing it won't come back to haunt me. This whole throttle servo issue can go from friendly advice to all out flame war in nuthin flat! I almost feel I should just keep my mouth shut, Besides I could be wrong, my testing is actually limited. BUT all of these servo failure posts is driveing me crazy! So Im' gonna throw it out there for anyone willing to give it a try. I hope it helps!
First; a big fat disclaimer .I am shareing this tech tip in the hopes it helps LOSI 8IGHT-,1.0 ,2.0 buggy or truggy owners solve ONE problem that causes throttle servo failures. I WILL NOT GURANTEE this tip as an end all, be all, cure all, for every possible cause of servo failures..If you don't follow LOSI's throttle setup addendum sheet. If you adjusted you'r idle screw with the servo fighting to hold the carb closed and now the carb is sticking, this mod ai'nt gonna do squat! If you have the throttle linkages setup on some goofy angles that are causing the servo to hang up n bind, you'r servo is as good as toast! And . I hate to say this , BUT I FEEL I REALLY HAVE TO' If you try this tip with a servo that has already been used offroad in a LOSI 8ight (of any type) THE DAMAGE MAY ALREADY BE DONE, AND IT'S JUST A QUESTION OF WHEN THE SERVO WILL FAIL! I BELIEVE THIS MOD WORKS and I HAVE BEEN TRYING THIS ON MY LOSI 8IGHT-T 1.0 and I have yet to experience a servo failure! On the bright side, the mod is not hard or expensive . So here it is;Step 1; Before you go to the LHS , measure the space beneath the throttle servo ,if you have less than 3.5 mm then, search through you'r spare parts and find the throttle servo spacers ( A-4453 ) and if you already used them or can't find them, then add em to you'r shopping list. While you'r at it add this #( 1) LOSI=( A-9415 ) to the list.These are servo mounts for the LOSI XXX-NT and MAYBE a set(4) of 4/40 x 5/8 "bolts, now make the decision on a replacement servo Go get em. and proceed to Step 2 .
Step 2 ;A ; remove , the right side chassis guard, radio tray, and throttle servo, and clean everything up. B; refer to LOSI's instruction manual and find the chart that explaines if you are to use the spacers for you'r particular servo. If the chart tells you to use the spacers then use 2 sets and the longer 4-40x5/8" bolts if the chart tells you not to use any spacers use at least 1 set (you want 3.5-4.0 mm of clearince between the servo and chassis )Don't bolt the rear of the servo down yet, this is just a trial fit!C ; instead of useing the A-4421 servo mounting backplate for the rear of the servo, trial fit one of the A-9415 mounts you bought in it's place. you want the 2 legs faceing down toward the chassis, the solid end up (against the radio tray) try it both ways to see witch fits you'r servo better (the upper mounting holes are offset for different size servos, D ; Once you have determined the best fit mark the outside leg of the a-9415 mount. remove the servo and the A-9415 mount from the radio tray and reinstall the radio tray onto the chassis bolting it up just like you normally would. E; With the radio tray remounted to the chassis you need to take carefull measurements to determine the EXACT LENGTH AND SHAPE OF THE A-9415 MOUNT ! it will be too long and the outside leg will interfere with the right side chassis guard. make carefull measurements and try to end up with a SNUG fit . I started by trimming 4mm off the top and cutting off most of the outside leg. then fine trimming from there on the inside leg that contacts the chassis sitting flat. On THE 2.0 radio tray you will need to rerout the battery wireing or trim a little clearence on the mount for the wires. F; Once you have the standoff to the proper shape and length reinstall the servo with the spacers and standoff, double check you'r work, reposition the carb for a smooth action, and finish with the setup addendum sheet. good luck . the goal is simple, you are turning the new mount into a rear standoff /support for the back of the servo and raise the servo to get more clearance. WHY? because THE CHASSIS IS FLEXING UP AND WHACKING THE BOTTOM OF THE SERVO this standoff is simple ; When the chassis flexes up, from a jump the chassis will push up on the standoff wich will push up on the rear of the servo(keeping the servo away from the chassis ) Unlike a stiffener or a more ridgid radio tray, that holds the servo in a steady position for it's whipping . I will try to post some pics or diagrams tommorow but when you have the mount bolted on the radio tray it shoulden't be hard to figgure out. mottman .

[mottman]

mottman here ,

Anybody try this yet ? I am still working to post some pics , hopefully I can get em up soon . Sorry for the delay .

[mottman]

sorry it took so long . here are some pics , more to come .

[mottman]

here are some more pics of the standoff mod

[mottman]

Here are the last of the pics explaining the throttle servo mod . As you can see it is'nt real hard or complicated . There are NO MODIFICATIONS TO THE SERVO OR CHASSIS OR RADIO TRAY ! You'r modifieing a 6.00 part , adding 2 or 4 servo spacers and useing 4 , 4/40x5/8" bolts ( and thats only if you'r useing all 4 servo spacers )

[eurofocus]

Here are the last of the pics explaining the throttle servo mod . As you can see it is'nt real hard or complicated . There are NO MODIFICATIONS TO THE SERVO OR CHASSIS OR RADIO TRAY ! You'r modifieing a 6.00 part , adding 2 or 4 servo spacers and useing 4 , 4/40x5/8" bolts ( and thats only if you'r useing all 4 servo spacers )

I was told to put larger spacers between both my servos, just haven't gotten to it yet. Good pictures to help explain this! Already had a servo horn (plastic) strip on me, so before I track it again i'll be adding spacers/shims to help prevent them from being bashed by the chassis from the inevitable radio tray flex.

[mottman]

This mod wont help stop you from stripping out the plastic servo horns , for steering I would recommend an aluminum horn . This mod prevents the throttle servo from completely dieing , it's been working good for me so far ( and if everyone knew what servo I am useing they would either laugh or cry ) . I dont know what happened to the text I added to each pic to further explain this setup . it gives alot of good , ez to follow details . Sux being computer illiterate !

[mottman]

Argh ! I hate computers sometimes ! Any friendly / computer expert moderators out there who wouldn't mind helping this tech dunderhead , move or restart this post , and maybe figgure out what happened to my picture's text ? Please . Pretty please ?

[mottman]

http://forum.losi.com/showthread.php?p=31713#post31713

[Sein]

I have a new servo on the way and I am gonna try this mod. My 8t is eating servos like there starburst.
And I do set my EPA's. My throttle travel was at 60% of it max travel and brakes were at 69%. My steering servo works great but that throttle and brake just keeps getting ate up. :(

[mottman]

Sein , I really hope it helps . Although it may be painfull , try to grind through my long written first post on this thread . The big important things to remember ;

A , be sure you trim the standoff to a SNUG fit .

B , if you hardmount you'r servo , use enough spacers to achive AT LEAST 3MM OF CLEARANCE BETWEEN THE BOTTOM OF THE SERVO AND THE TOP OF THE CHASSIS . MINIMUM !

C , If you cushion mount you'r servo , make that 3.5 mm . MINIMUM !

D , Of course , follow LOSI'S addendum sheet ( to the letter ! )

E , make sure the carb is't sticking and the linkages are'nt binding at any point in they're entire movement . goes without saying , you gotta fix those issues as well ( just as important ! )

F , Ocassionaly ( I would say every 2 gallons or so ) check the mount for damage and see if it is still a SNUG fit . After a while the standoff will become a little bit shorter ( the chassis is hammering up on the bottom of the standoff every time it flexes ) Once the standoff has 0.040" or so, slop , it may be time to replace or add some washers on top of it as shims to make it a SNUG fit again .

G , Be sure to tell us how / if it is working for you . ( feedback please )

Thanks , Mottman .