Night of the Living Numpty - Part I

[Ted Maul]

Ok so having a great evening, but fed up so going to hold myself up to ridicule here.... twice
Part I. Been out of the scene for a long time and now have my 1st brushless motor and speedo, yay - SP GT2 and SP 6.5 pro.

Cannot for life of me solder the 5 wires to the speedo, eitehr the black/red power or the three motor wires. Motor connections fine, but *******d if I can do the speedo end. Iron is very old, like 20 years old I used at Uni for pcb work, marking faded but think it says 25w which sounds a bit feeble, is this the problem? Heatsink gets plenty warm enough...

Is there a trick to this or am I just rubbish at soldering

[MRD]

When I'm doing a speedo I use the biggest iron I have and the trick is to be quick. A small iron will cool down too quick and just heat up the speedo. The thick wires make it harder too as they take away heat quickly and suck up all the solder. I don't find it that easy so you're not alone, but a big iron and nice clean joints with fresh solder will make it easier.

[SHY]

I'd say 25W is way WAY too cold! Try a 65 or 100W and make it quick! (I use an el cheapo 100W and that works like a charm)

Plus make sure the tip is clean, use a wet sponge to wipe it off quite often.

Good luck! I've been there myself!

[SHY]

Oh, and make sure you apply solder to the wire ends before you solder to the ESC. A "helping hand" is of great use here, as the wires get smokin' hot!



-very handy for all the soldering actually, can't live without it anymore!!!

Another tip is to use cleaning gum to make the ESC stay put while soldering.

So here's the procedure:

1) hold the ESC in place to your workbench with cleaning gum (for instance Xceed), at an angle is often practial
2) use the helping hand to hold the wire one at a time, apply solder to the end first.
3) Let it cool down, positon the wire into the ESC hole (I sometime enlargen them with a Dremel to get the wire through). Use the helping hand to keep it in position.
4) Hold the soldering iron with one hand, the solder with the other...

BINGO!

[MRD]

I still don't know why they don't make the 1/10th speedos with plugs like the v3 Speed pash motors . It would save alot of hastle.

[SHY]

Even better: Make a standardized 3-face plug for all speedos and motors, which could then be bought in different lengths... (like a beefed up sensor cable)

I just hate three things about RC cars: Soldering, cleaning and re-building ball diffs!

[Ted Maul]

Cheers for all the advice, speedo did get warm but even dropping solder on wires didn't help as the solder wouldnt melt when wire touching speedo so guess iron just too weak.

don't feel quite such a numpty now, thank you!

[Rich D]

Hey Ted

Not to say that anyone who has given advice is wrong here but 25W iron is fine, thats what i use, mines an Antex 25W. As stated its imperitive that the tip is clean. It should be shiny - if its not use a flat file on the tip. The tip needs to have a flat ideally - not a pointed one ! I constantly use a bit of wet kitchen towel to wipe the burned flux away after each joint. You need only tin the ends of the wires and also tin the speedo where you are trying to solder to. It helps if you have decent rosin core solder - the Schumacher stuff is good as is the MuchMore stuff too.

I tend to mount the speedo onto my workbench with some servo tape ( Losi stuff is good ), clean the tip, apply a small amount of fresh solder to the tip just prior to use to help with heat transfer, then apply the heat to the speedo pcb whilst pushing the wire through from underneath. If you hold the heat onto the wire itself for too long then it will draw the solder down it making the wire rigid and youll have a crap dry joint too !

After a few practice runs you`ll be able to acheive a factory shiny joint without too much trouble. If you remove the heat a fraction before you remove the solder it helps to get that smooth shiny finish on the joints as below.



Hope this helps

Rich

[RogerM]

Size of the tip is important ... a bigger tip will hold heat longer when in contact than a smaller tip which will cool quickly.

[CrashBangWallop]

Originally Posted by Rich D

Hey Ted

It should be shiny - if its not use a flat file on the tip.
Hope this helps

Rich

Sorry but have to disagree here - If you file the tip on a modern soldering iron i.e. one with a coated tip you WILL ruin it.

If you have a soldering iron that has an old fashioned solid copper tip then file away ! But still best to use a bronze brush for cleaning the tip then re-tin the tip immediately, Or use a damp NATURAL sponge to clean the tip.

Soldering any RC stuff with a soldering iron of less than 45 watts will overheat speedo's and motor connections.

Key to success is decent solder - the stuff with lead in it and a flux core, 45W + soldering iron, make sure all joints to be made are clean and pre tinned. And last but not least be quick.

Personally use a 75W WELLER soldering iron used for lead light windows with an 8mm round chiselled tip. £35 from a DECENT tool store.

[racingdwarf]

I'm with the large Iron camp here, I used my 65w large tip, yes you do have to keep an eye on the case with a large tip or you will have melt marks oh to soon, but you can work fast without to mutch heat transfering to the speedo. but each to there own

I agree on the plugs on the ESC would be nice, think speed passion already do

[Rich D]

That's all good dude and works fine for you I have no doubt. You may of burned a speedo out with a low wattage iron but I've never managed to since I started racing in 1987. Nor have I managed to ruin a tip by filing it. Maybe the Antex tips are different. Nothing wrong whatsoever with my joints. I used a 100w iron to build cells back in the day but personally think it's very much overkill for pcb work. The solder melts instantaneously upon touching the tip onto the board with my 25W iron. Anyway. Peace.

Originally Posted by CrashBangWallop

Sorry but have to disagree here - If you file the tip on a modern soldering iron i.e. one with a coated tip you WILL ruin it.

If you have a soldering iron that has an old fashioned solid copper tip then file away ! But still best to use a bronze brush for cleaning the tip then re-tin the tip immediately, Or use a damp NATURAL sponge to clean the tip.

Soldering any RC stuff with a soldering iron of less than 45 watts will overheat speedo's and motor connections.

Key to success is decent solder - the stuff with lead in it and a flux core, 45W + soldering iron, make sure all joints to be made are clean and pre tinned. And last but not least be quick.

Personally use a 75W WELLER soldering iron used for lead light windows with an 8mm round chiselled tip. £35 from a DECENT tool store.

[CrashBangWallop]

I have to make an addition to my previous post and that is there is no substitute for practice and experience no matter what equipment you have.

And by practice, myself and Rich D seem to have had over 50 years of playing with hot metal ! ! POB.

[SlowOne]

Originally Posted by CrashBangWallop

Sorry but have to disagree here - If you file the tip on a modern soldering iron i.e. one with a coated tip you WILL ruin it.

If you have a soldering iron that has an old fashioned solid copper tip then file away ! But still best to use a bronze brush for cleaning the tip then re-tin the tip immediately, Or use a damp NATURAL sponge to clean the tip.

Soldering any RC stuff with a soldering iron of less than 45 watts will overheat speedo's and motor connections.

Key to success is decent solder - the stuff with lead in it and a flux core, 45W + soldering iron, make sure all joints to be made are clean and pre tinned. And last but not least be quick.

Personally use a 75W WELLER soldering iron used for lead light windows with an 8mm round chiselled tip. £35 from a DECENT tool store.

Gotta support Rich D here and discourage those new to soldering from wielding a 75W iron anywhere near current model motors and electronics.

Like any skill, you can use the wrong tools if you have a great deal of it, but if you are new to soldering, then do not use anything over 30W for soldering motors and speedos, or take anything over 18W near circuit boards and RC connections.

The key to any good soldering joint is clean parts and use of flux. I never hear people talk about flux, but it is vital to a clean, solid joint using the minimum amount of solder. With a proper paste flux, you can use any solder.

When you solder, and you have correctly tinned both parts, the joint should be made in under three seconds. If it takes more than that to make the joint, you've not done the right prep. Using a 25W iron for almost everything, I have no problems with motors or speedos providing the joints are prepared, the wire is hot and the iron has a drop of solder on it to aid heat transfer. HTH

[Ted Maul]

Originally Posted by SHY

Oh, and make sure you apply solder to the wire ends before you solder to the ESC. A "helping hand" is of great use here, as the wires get smokin' hot!



-very handy for all the soldering actually, can't live without it anymore!!!

Another tip is to use cleaning gum to make the ESC stay put while soldering.

So here's the procedure:

1) hold the ESC in place to your workbench with cleaning gum (for instance Xceed), at an angle is often practial
2) use the helping hand to hold the wire one at a time, apply solder to the end first.
3) Let it cool down, positon the wire into the ESC hole (I sometime enlargen them with a Dremel to get the wire through). Use the helping hand to keep it in position.
4) Hold the soldering iron with one hand, the solder with the other...

BINGO!

Got one of these saturday from amazon, £7 delivered and mine had a soldering iron stand too.... 100w iron arrived, will try again this week..

[SHY]

It'll be much better, I promise!

Remember to clean the tip with a wet sponge or a copper brush now and then. You may also give the soldering iron a "wack" to get rid of old solder on the tip. But don't go wild there...

Happy soldering!

[samd]

Originally Posted by Rich D

That's all good dude and works fine for you I have no doubt. You may of burned a speedo out with a low wattage iron but I've never managed to since I started racing in 1987. Nor have I managed to ruin a tip by filing it. Maybe the Antex tips are different. Nothing wrong whatsoever with my joints. I used a 100w iron to build cells back in the day but personally think it's very much overkill for pcb work. The solder melts instantaneously upon touching the tip onto the board with my 25W iron. Anyway. Peace.

The soldering or Rich's car is so good it goes extra fast on the straight bits

[Rich D]

Originally Posted by samd

The soldering or Rich's car is so good it goes extra fast on the straight bits

you almost had me in the final Sam - better luck next time. See you at a few regionals, get yourself there, no excuses !

[Ted Maul]

All done and dusted within about 20 mins, even fiddly capacity wires.

Car is unfeasibly fast I have to say, fan is a bit noisy but maybe unnecessary anyway.....

Thanks for all your advice guys, much appreciated (and no i won't post pictures as I didn't cut wires to size so it looks a bit messy but have not decided whether to swap chassis so not going to chop wires until I have)