3LikesTekin RX8 1/8 Scale Brushless ESC Thread
02-28-2010, 09:01 PM
#6811
John_stu, if the problem is poor performing lead-free solder on the MOSFETs or poor solder joints on the control board, it shouldn't be too hard to hit everything manually with a temperature controlled soldering iron at 700 F. Best thing would be to remove the solder from the cracked joint using desoldering braid and replace it with some 60/40 lead/tin solder. Cracked joints are about the easiest thing you can repair yourself in electronics, provided you can see the crack (magnifier helps).
Tekin could be in kind of a bind because Europe requires ROHS lead-free solder compliance, and they can't make a seperate product for Europe and the US. But, unfortunately, lead-free solder has inferior performance to regular old 60/40 solder. But the good news is that if thats indeed the problem, I will just take my board and hit all of the joints manually at 700 F and then put some new 60/40 solder on the MOSFETs (grounding strap and grounded, temperature controlled iron recommended for this step).
Tekin could be in kind of a bind because Europe requires ROHS lead-free solder compliance, and they can't make a seperate product for Europe and the US. But, unfortunately, lead-free solder has inferior performance to regular old 60/40 solder. But the good news is that if thats indeed the problem, I will just take my board and hit all of the joints manually at 700 F and then put some new 60/40 solder on the MOSFETs (grounding strap and grounded, temperature controlled iron recommended for this step).
03-01-2010, 01:17 PM
#6812
John_stu, if the problem is poor performing lead-free solder on the MOSFETs or poor solder joints on the control board, it shouldn't be too hard to hit everything manually with a temperature controlled soldering iron at 700 F. Best thing would be to remove the solder from the cracked joint using desoldering braid and replace it with some 60/40 lead/tin solder. Cracked joints are about the easiest thing you can repair yourself in electronics, provided you can see the crack (magnifier helps).
Tekin could be in kind of a bind because Europe requires ROHS lead-free solder compliance, and they can't make a seperate product for Europe and the US. But, unfortunately, lead-free solder has inferior performance to regular old 60/40 solder. But the good news is that if thats indeed the problem, I will just take my board and hit all of the joints manually at 700 F and then put some new 60/40 solder on the MOSFETs (grounding strap and grounded, temperature controlled iron recommended for this step).
Tekin could be in kind of a bind because Europe requires ROHS lead-free solder compliance, and they can't make a seperate product for Europe and the US. But, unfortunately, lead-free solder has inferior performance to regular old 60/40 solder. But the good news is that if thats indeed the problem, I will just take my board and hit all of the joints manually at 700 F and then put some new 60/40 solder on the MOSFETs (grounding strap and grounded, temperature controlled iron recommended for this step).
funny i was thinking the exact same thing ..........
03-01-2010, 01:54 PM
#6813
so has anybody fixed there broken solder joints their self?
03-01-2010, 02:20 PM
#6815
I had the "chassis hits the ground and cuts out" problem last summer and was able to find the loose joint and fix it. Lasted 7 months and then had another issue, but being a team member I decided to mail er in since I could afford the time this time around. In the last 15 months I've gone through about 10 MMM's (before the rx8 came out) and only 1 rx8. 3 or 4 mmm's were v3 to boot.
03-01-2010, 02:47 PM
#6816
so where was the loose/cracked joint. any pics?
03-01-2010, 02:55 PM
#6817
I don't have an pics because I fixed the thing right at the track to finish the day.
In my case it was the pot hanging off the bottom of the lower board that had one bad joint. From others who have opened them up it sounds like there are a couple other places it could happen, but I don't know personally.
In my case it was the pot hanging off the bottom of the lower board that had one bad joint. From others who have opened them up it sounds like there are a couple other places it could happen, but I don't know personally.
03-01-2010, 03:36 PM
#6818
Broken solder joints are very common on circuit boards that are put into use in things that get bounced around. I had a Silverado that didn't want to shift into 4wd, push button style. I took the switch apart and could see that the joints had cracked where the plug connected to the cb. I resoldered it, with 60/40, and it never gave me trouble again. If this theory about the silver solder is true I'm confident Jim and the crew will get it figured out. I know it's hard to be patient when you just want to race and your stuff keeps letting you down but please just hang in there. The performance difference will be worth it in the end.
03-01-2010, 04:46 PM
#6819
Many of these lead free solders contain a little silver, so they are actually stronger. But a lot of these new alloys are more brittle than good old lead. Anyway, glad its solder joints that are causing most of these problems because its something you can semi-quickly fix in the field.
Also, getting something mass produced with 60/40 solder might be next to impossible these days unless you are making aerospace or medical stuff at a high price. I think almost everybody else has converted to lead free solder. Plus, who knows about the thermal expansion and contraction properties of most of these new alloys. The RX8 is undergoing some pretty serious temperature cycling every time you run it.
Also, getting something mass produced with 60/40 solder might be next to impossible these days unless you are making aerospace or medical stuff at a high price. I think almost everybody else has converted to lead free solder. Plus, who knows about the thermal expansion and contraction properties of most of these new alloys. The RX8 is undergoing some pretty serious temperature cycling every time you run it.
03-02-2010, 12:34 AM
#6820
03-02-2010, 06:22 AM
#6822
Currently my RX8 is missing one of the solder posts and I have the wire soldered directly into the board. I am a very accomplished technician and have good equipment but I was unable to resolder the post to the board. I could not get the post hot enough as soon as it would touch the board it would disapate the heat. I had repaired the same RX8 last summer (loose solder post) and it worked fine up untill 7 min in to a 10 min main at CRCRC. I was running 3rd behind Brent Thielke and Jesse Robbers.
03-04-2010, 02:33 PM
#6823
Those posts and the heavy copper boards require an immense amount of heat to solder correctly. It can be done but it's a royal pain and you're better off sending it in and letting us do it.
03-04-2010, 04:59 PM
#6824
i want to share my experience that had since i've owned my rx8. first off the rx8 has been completely unreliable for me, in 5 months it has stopped working 5 times every time it has failed its the same thing something comes loose on the circuit board. so its spent about 3 of the 5 months i've owned it in the mail going back in forth to and from tekin. so i've had it in my possession about 2 out of the 5 months i've owned it and i race once a week max. 1 of the units died on the first battery every run thru it and 3 lasted a full race day and the most resent red heatsink version lasted almost a month but i only race one time a week max.i even have tryied mounting them with http://www.amainhobbies.com/product_...ng-Gel-1-Sheet but same results.each time i send it in for repairs it takes 2 1/2- 3 weeks to get it back. and each time tekin has reassured me they have the bad solder joint issue worked out and that i should not have any more problems.The last time it died i got upset that it has failed so many times and i decided to contact tekins president jim campbell and speak with him about the problems im having. i told him i did not want the product anymore i wanted to return it for a refund but he talked me into giving it one more try because he said he would ship me out another pcb board today ( week ago monday am) and that i would be racing by the weekend and that he would send a few extra boards to my local track so we had spares because im not the only one who is having issues with the rx8 at my local track, so i agreed. friday came and so did the mail but no package from tekin so i called jim and he told me it shipped so i asked for a tracking # and he told me the shipping person went home and wont be back till monday but my order did definitely ship and i should see it any day. so mondays mail came no package so i sent jim an email asking for the tracking#, no reply.tuesday came and so did the mail no package so i called tekin and the person answering the phone tells me your order should go out any day now.so me and jim have spoke several times now over the past week through email and on the phone and each time week speak he tells me your board will ship soon. so to be honest i have been getting very agitated about the whole thing. in jims email he told me he didnt ship the board to me or my local track because he is waiting to see what i post on rctech because i've been bashing the rx8? soo what he is threatening not to help me or people at my local track if i tell others about the problems im having with my rx8?after explaining to jim that i only race in the winter and i've spent 3 of the 5 lasts months of my race season waiting for my rx8 to be repaired and explain that i have spent $60 shipping it back 5 times and all the race entrance fees i've lost when the unit failed and how my race season is ruined and his response "you should have a spare esc" well right now time a tough for me im lucky to be ablt to aford a car never mind a spare esc so he says will make it up to me by sending me a free t-shirt and still to this day as far as i know the boards have never been shipped to me or my local track and at this point i think i have been treated very poorly i think i deserve to be able to send my rx8 back for a full refund because of the extreme problems im having with it.i would really prefer not to use tekin products anymore or at least until then can fix the rx8 problems and i do understand that its not all the rx8's have these issues but a lot do and mine is one of them.this really has ruined my whole rc season i've spent so much time being aggravated about this rx8 breaking almost every time i use it i haven't had a chance to have much fun even if i get this stuff worked out im done for the season, this whole experience with tekin and the rx8 has really sucked the life out of me...............buy a mamba monster i would if i could get my money back from tekin i've asked jim several times if i could get a refund if i sent the rx8 back but he has not answered me in emails and from when i asked him on the phone it really didn't sound like that was an option,and after this "bashing" in sure tekin is done with me as i am done with them.
anyway jim hope you enjoy the $330 i paid for my broken rx8 and my $40 for the hotwire i no longer need ,spend it wisely
anyway jim hope you enjoy the $330 i paid for my broken rx8 and my $40 for the hotwire i no longer need ,spend it wisely
03-04-2010, 06:17 PM
#6825
soo.....did ya get the free t-shirt? 
After the 3rd time I woulda dumped it on someone else after they fixed/replaced it and got a different brand ESC.
After the 3rd time I woulda dumped it on someone else after they fixed/replaced it and got a different brand ESC.