diy solar

diy solar

DIY BUSBARS

TKB4

New Member
Joined
Dec 2, 2019
Messages
208
How do you make/cut DIY busbars? I have used cutoff wheels on copper, Miter/cutoff saw on aluminum as well as pipe cutter and then flattened the pipe for smaller projects of both and brass and hacksaw for smaller projects. Sort of a dedicated metal cutoff or bandsaw what have others used ?
 
Hacksaw or cutoff Wheel.... and a drill press. I have considered buying a small mill to make one or more of the holes slightly oval.... but have not pulled the trigger on that expen$e yet.

Do you plate your copper? If so how?
 
I cut my copper/aluminum/brass with hacksaw, chop saw, grinder. A bench grinder with wire brush cleans burrs well.

For backwoods elongated holes- drill 2 spaced holes leaving some meat in between holes
Dremmel with micro disk cutter or a file to open the flat sides. It can be time consuming & fine work.
OR
If you have a drill press and a cross slide milling vise, a carbide burr works well. Drill 1st hole. Adjust item in vise. Start milling.

Tinning copper.
Use a CLEAN, STIFF bristle Stainless or brass brush. Stainless seems to work best - clean your copper well. Use sandpaper or a rotary brush if it is very dirty copper. Use a file if a flat surface is needed in the application.
Apply good quality flux. Heat copper with propane torch. When hot enough to freely melt solder, apply a high tin content (plumbing) solder ensuring complete coverage of the copper. Shake off the excess while hot. Reheat if needed to reflow solder to a smooth surface. Leave item for a few seconds for the solder to solidify (flash), then clean the hot item with a damp cloth. This removes any excess flux which may otherwise result in corrosion of the copper or other points of contact. .
 
For backwoods elongated holes- drill 2 spaced holes leaving some meat in between holes
I want a *much* smaller elongation than that. Measure fairly closely and I try to make the holes only slightly larger than the studs...but inevitably the holes will be fractionally out of position. I typically only need to elongate the hole by less than 10% of the diameter.
If you have a drill press and a cross slide milling vise, a carbide burr works well
I have tried that with an end mill but it did not work very well. Could you link to a burr that you are talking about?
 
Tinning copper.
Use a CLEAN, STIFF bristle Stainless or brass brush. Stainless seems to work best - clean your copper well. Use sandpaper or a rotary brush if it is very dirty copper. Use a file if a flat surface is needed in the application.
Apply good quality flux. Heat copper with propane torch. When hot enough to freely melt solder, apply a high tin content (plumbing) solder ensuring complete coverage of the copper. Shake off the excess while hot.
I have a solder pot that I dip the busbars in (at least the shorter ones).
Shake off the excess while hot. Reheat if needed to reflow solder to a smooth surface.
That is important! You want the bar to be as smooth as possible. One little bump can hold the bar off the terminal pad and create a very poor contact. I often wipe the bus bar with a cloth while the solder is still flowing hot. That gives a very nice smooth surface.

I have also tinned with electrolysis..... but it is a royal PITA

 
You can try Liquid Tin. Coats as fast as the liquid touches copper. Here’s a before and after pictures of my DIY bus bars.
 

Attachments

  • E51A9BCC-38B5-4C8B-9A67-C1742A8A06F0.jpeg
    E51A9BCC-38B5-4C8B-9A67-C1742A8A06F0.jpeg
    76.4 KB · Views: 89
  • F82E6519-D99A-41CD-BFD9-F6F1212F820D.jpeg
    F82E6519-D99A-41CD-BFD9-F6F1212F820D.jpeg
    156.1 KB · Views: 89
  • 2B92EECD-199E-46B0-89EB-A77E862A1496.jpeg
    2B92EECD-199E-46B0-89EB-A77E862A1496.jpeg
    85.1 KB · Views: 90
You could try a jig to get all of your holes the same spacing.
Drill the first hole in the bus bars and sit that on a pre-made piece of wood with a bolt in the position of the hole, do up the nut on the bolt to hold the bus bar in position and clamp the wood in a vice on the drill press and drill the second hole at the correct position. Now just undo the nut and replace the bus bar with the next one to be drilled while not moving the wood.
Might need some fine tuning with regards to the wood thickness but im sure it wouldnt be too hard.
Just a thought.
 
if the busbars are for indoor use with lithium batteries I do not bother with "tinning".
Agree with the liquid tin as a nice protective coating (a bit pricey) but it puts on a nice thin (really thin) layer (buy it when you need it, does not like long term storage, at least for me).

definitely make a jig to setup your busbars for drilling. I would not recommend you try and "mill" with a drill press.
There is a huge difference between mills and a drill press and it has to do with the lateral (sideways)forces on the quill bearings. A drill press is designed to ONLY take forces directly along its vertical axis (up and down). Any sideways force rapidly starts to damage to quill bearings/housing (it just is not made for that). A mill has bearing surfaces that are designed to handle lateral forces. You can get an x/y table and try to mill with your drill press but, well, be really really careful as you will certainly start to cause a lot of runout in your drill press.
The safest way is to just drill a series of hole and then use a burr with a hand grinder to even things out. fyi, put a release agent (like wax) on your burrs to keep them from getting gummed up hehe
 
I have also tinned with electrolysis..... but it is a royal PITA

Heck, I must be twisted because I thought the plating process was a fun project. Doesn't take long either, takes more time to prep by scrubbing the copper for plating.
 
Carbide Bur set.
 
I have 3/8"x1" aluminum bar stock that I will eventually get around to using to make bus bars for my LiFePO4 cells. I'll cut to length using a chop saw with a Freud Diablo non-ferrous 48t blade. Holes for the posts will be drilled with a regular drill bit on my drill press. Then to create a slight elongation I'll use an aluminum spiral router bit, possibly on the drill press but the router is also an option. I'm not going to cut much elongation since my cells are in a compression frame and don't move much at all.

I'm not planning to put any finish on the bus bars. I may insulate the area between the terminals with heat shrink tubing. Or, I may get lazy and just use electrician's tape.
 
Heck, I must be twisted because I thought the plating process was a fun project. Doesn't take long either, takes more time to prep by scrubbing the copper for plating.
It was fun the first time. Interesting the second time. A chore the third time. If solder-plating wasn't so much easier I would still do the electrolysis.
 
I agree with others in the need to not have tinned bus bars since they’ll be used indoors in a protected environment. The desert environment here does not have a lot of humidity to speed up corrosion so another reason I originally went with bright copper. However, I revised my build to tin the copper bus bars because of the poorly machined stud holes on the aluminum battery terminals. I want to attach the bus bars to the batteries and virtually never touch them again. That’s why I have a middle stud point for my connections. So a light tinned surface plus Ox-Gard became required. Normally I prefer to have the bright copper finish bars. That way if/when oxidation is happening I can see it sooner on the bright copper as it changes color than on tinned surfaces. With flooded acid batteries, it’s standard operating procedure to fully disable the battery connections at least once a year for cleaning off the oxidation/contamination from the acid. With these aluminum terminals on the LiFePo4 cells, the less you screw and unscrew the studs/bolts the better.

As for fabricating the bus bars, I have metal fabricating equipment including a metal plate shear, hydraulic punch, knee mill... So I was able to make nice precision bars for all the good that did. Because at least half of the bus bars had to be manually filed on the stud holes in order to get them on to the not so straight studs. Over sized punched oval holes allowed easy fit but sloppy holes make for less electrical surface contact. So building your bus bars with hand tools works just as good as using fancy machinery because of the lack of precision on the battery terminal holes requires manual adjustments/tuning for these inaccuracies.
 
Because at least half of the bus bars had to be manually filed on the stud holes in order to get them on to the not so straight studs.
That is my finding as well. The holes were very close, but not perfect. Making the holes just 1/4mm oval would have made them fit.
 
rat tail file or chain saw file can elongate
Yup....that is what I use. Unfortunately the copper gums up the file rather quickly..... Does anyone know how to easily clean the soft copper off the file?
 
Hacksaw or cutoff Wheel.... and a drill press. I have considered buying a small mill to make one or more of the holes slightly oval.... but have not pulled the trigger on that expen$e yet.

Do you plate your copper? If so how?
No I dont plate the copper but I did some chrome plating in chemistry class in college. Doubt its really worth it.
 
You could try a jig to get all of your holes the same spacing.
Drill the first hole in the bus bars and sit that on a pre-made piece of wood with a bolt in the position of the hole, do up the nut on the bolt to hold the bus bar in position and clamp the wood in a vice on the drill press and drill the second hole at the correct position. Now just undo the nut and replace the bus bar with the next one to be drilled while not moving the wood.
Might need some fine tuning with regards to the wood thickness but im sure it wouldnt be too hard.
Just a thought.
I make a long pattern "jig" first and drill all the holes for several bus bars (2-4 feet worth) then cut them apart which doesnt need to be very accurate as log as they ar not too long
 
Yup....that is what I use. Unfortunately the copper gums up the file rather quickly..... Does anyone know how to easily clean the soft copper off the file?

I would try using a pin point nozzle on my air compressor real close to it .... and have safety glasses on.
 
Back
Top