What's the best trimming tools in the industry?

[LektroiD]

When I use multiturn trimmers, I find no matter what type of screwdriver or trimming tool I've used, they slip off the slot nearly every turn. I was wondering which are the best trimming tools available. I was thinking something with a hood to surround the set screw so it can't slip off, if such a thing exists.



What are the best tools in the industry to use for trimming this type of trimmer?

[Tac Eht Xilef]

For trimpots I've got a couple of Spectrol tools like these - one to use, the other to use when I can't find the first one, and visa-versa. Together they've lasted over 20 years of near-daily use.

Still looking for a good set of trimcap/RF alignment tools though...

[Richard Head]

I was thinking something with a hood to surround the set screw so it can't slip off, if such a thing exists.

They do exist, exactly as you describe, and they are cheap. They also have a metal blade inside the shround.
For RF work I use a ceramic bladed screwdriver. They are a bit more expensive but don't affect the tuning at all. They are also more fragile so have to be handled with a little care.

[Tac Eht Xilef]

Forgot to mention: yeah, the Spectrol tool I linked has a shrouded blade at one end and an open blade at the other.

[VK5RC]

Bizarrely i use the biggest screwdriver that fits the slot,  it slips out less often!

[Rick Law]

When I use multiturn trimmers, I find no matter what type of screwdriver or trimming tool I've used, they slip off the slot nearly every turn. I was wondering which are the best trimming tools available. I was thinking something with a hood to surround the set screw so it can't slip off, if such a thing exists.

After the same frustration, I came up with this.

Photo 1: The tool with the "retainer nuts".  The "bolt like" (hollow, both ends female, the silver color one) is the one I used.  These nuts/bolt are used to screw two RS232/VGA cables together, or at the PC side (KVM side) to secure the cable.  The "bolt" is "secured" onto the screw driver tip with heat shrink cable (later added a piece of plastic with a hole to hold it in place better, but without that will work too).


Photo 2: Close up of the tip with the hood in "normal" place so the trimpot screw fits inside the "bolt" and wont slip off as the screw driver turns.


Photo 3: The "bolt" (hood) pulled back exposing the screw driver blade.


I have been using it for over a year.  Works great.
Rick
 

[free_electron]

that is a clever idea !

even better is : ditch trimmers. use dacs with eeprom on board. they are often cheaper than trimmers ...

[mazurov]

Still looking for a good set of trimcap/RF alignment tools though...

In a set of nonames looking similar to yours I have a couple of all-plastic ones which I use to trim probes and HV blocks in my scopes. For pots I use a small flat screwdriver with a piece of heatshrink shrunk over a stem and unshrunk (or formed around a trim screw ) over a blade - this allows me to have a good screwdriver (i.e., Wiha) and trimming tool at the same time.

[poorchava]

Funny, I just made that one:
took a 2.5mm nail, cut off the head, ground the flat blade on the end, heatshrunk the end (just didn't heat the part which goes around the blade). The i took some random piece of plastic round stock, drilled a 2.4mm hole and pushed the nail in.

[SeanB]

Plastic knitting needles and some work with a needle file works for me. The heatshrink idea is a good one to add to the next ones I make though.

[LektroiD]

For trimpots I've got a couple of Spectrol tools like these - one to use, the other to use when I can't find the first one, and visa-versa. Together they've lasted over 20 years of near-daily use.

Still looking for a good set of trimcap/RF alignment tools though...

Just purchased the Spectrol tool. Apparently there's an equivalent Bourns tool which I may also buy for the same reasons you mentioned. Up until now I was using some old non-shrouded trim tools which came with my Moog Theremin a few years ago

[ajb]

I picked up some of the Vishay tools after seeing them mentioned here, and while they're a lot easier to use than a plain screw driver I frankly found them a bit annoying to use.  The shroud around the blade is big enough that it can be tricky to actually get the blade engaged in the screw slot, especially on smaller trimmers.  I found I had some 1/8"x0.014" brass tubing on hand that was a nice fit around a standard trimmer screw, so took matters into my own hands 

I bought some Wiha 2.5mm flat bladed screwdrivers, since these were a close match to the ID of the brass tubing.  Since I don't have a lathe, the best way I've found to cut short lengths of small brass tube is to chuck it into a cordless drill and (carefully!) score it with a utility knife, rocking the blade back and forth very slightly to expand the cut until you can cleanly snap it.  With a little practice it's much faster and cleaner than a proper pipe cutting tool, and while the piece is still chucked you can use a countersink tool to debur the inside and a file to clean and dress the outside of the cut.  Since the ID of the tubing is just a hair under 2.5mm, unfortunately it wasn't possible to just slide it over the screwdrivers and call it a day, so after cutting the tubing to ~20mm lengths I reamed it out with a #40 drill bit, stopping about 2mm from the end.  I did this with the tube held chucked in the drill and the drill bit held in a pair of vise grips, since the drill chuck holds the tubing much more firmly without deforming it than any other tool I had on hand.

The Wiha drivers have very nicely made tips with very crisp corners; knocking those corners down a bit with a file makes it much easier to install the sleeves.  After cleaning up all the parts, the last step is to slide the sleeves onto the drivers, with the un-reamed end towards the tip, and about 0.5mm or so of the sleeve extending past the tip.  The tip of the blade makes a very nice press fit in the un-reamed section of the tube, but I used a bit of Loctite for extra security.

The finished trimmer drivers provide a very easy fit around a standard 3/8" trim pot screw, and are much easier to align on smaller 1/4" trimmer screws, although if I were doing it again I might thin the tip of the screw drivers first to make it even easier to engage a screw.  As it is, though, the slight lip extending past the blade tip nicely centers the driver on the screw head, and a little twist reliably drops the blade into the slot with no fuss.

[David Hess]

Real screwdrivers are nice but the plastic tools with a small metal bit have the advantage of not affecting the circuit very much either electrostaticly or magnetically.  Non-conductive tools also keep mistakes from becoming catastrophes.  They also make expensive ceramic trimming tools so even the magnetic effect of a small metal bit is not present.

[rob77]

even better is : ditch trimmers. use dacs with eeprom on board. they are often cheaper than trimmers ...

i'm afraid that would work only for a very small subset of cases vast majority of cases require a trimpot and nothing else.

[Kjelt]

Free idea for Bourns and other trimmer manufacturers: use Torx screws 

[David Hess]

Free idea for Bourns and other trimmer manufacturers: use Torx screws 

Then we will need twice as many trimming tools.

http://xkcd.com/927/

[Rick Law]

Free idea for Bourns and other trimmer manufacturers: use Torx screws 

Then we will need twice as many trimming tools.

http://xkcd.com/927/

I would prefer a simple Phillips screw over Torx.  The "+" shape should prevents it from slipping off.  Phillips is also less picky on size.

...
I found I had some 1/8"x0.014" brass tubing on hand that was a nice fit around a standard trimmer screw, so took matters into my own hands 

I bought some Wiha 2.5mm flat bladed screwdrivers, since these were a close match to the ID of the brass tubing.  Since I don't have a lathe, the best way I've found to cut short lengths of small brass tube is to chuck it into a cordless drill and (carefully!) score it with a utility knife
...

Wow, you are a series trimmer.  You did a lot more work than my simple "hex nut with heat shrink" posted earlier in this thread.

Real screwdrivers are nice but the plastic tools with a small metal bit have the advantage of not affecting the circuit very much either electrostaticly or magnetically.  Non-conductive tools also keep mistakes from becoming catastrophes.  They also make expensive ceramic trimming tools so even the magnetic effect of a small metal bit is not present.

For a while, I used my set of Radio Shack plastic TV adjustment screw drivers.  In just about a month of use, the plastic worn out.  It became so soft it was not able to turn the screw.

You will need plastic of fairly good quality.

[DmitryL]

For a while, I used my set of Radio Shack plastic TV adjustment screw drivers.  In just about a month of use, the plastic worn out.  It became so soft it was not able to turn the screw.
You will need plastic of fairly good quality.

Now you can by pretty nice and cheap ceramic screw drivers. I think, they are made of that zirconium stuff that is used for ceramic knives.
Google "ceramic scredriver"

[Electro Fan]

I saw this comment on a GC Waldcom product review:

"Let me start off by saying I'm not disappointed in the slightest in the tools themselves. They are top shelf stuff. But people need to be aware these are conductive nylon tools and as such aren't suitable for high voltage like vacuum tube equipment. These work great on transistorized/IC electronic equipment and have nice variety of ends."

Is there a difference in conductivity between nylon and other plastic trimmer tools?  Does it matter for low voltage DC work, or only AC work, or mostly for high voltage AC work (like vacuum tubes)?  How about for an external trim pot on an oscilloscope plug-in?

Anyone have a recommended source of safe and effective trimmer tools?  Thx

Vishay Spectrol?
GC Waldcom?
Jonard?
Others?

[Sjokolade]

I bought this Hozan D-16 kit, have not used it much so far so I don't know if the plastic wears out or not.

Link to Hozan homepage

[KJDS]

even better is : ditch trimmers. use dacs with eeprom on board. they are often cheaper than trimmers ...

i'm afraid that would work only for a very small subset of cases vast majority of cases require a trimpot and nothing else.

A long time ago I saw a graph of decades vs number of adjustments in a companies products.

1960s   1000 adjustments
1970s    100 adjustments
1980s      10 adjustments
1990s         1 adjustment

Good design and a little digital control can solve most issues.

I did design a diplexer that had 48 adjustment screws that all interacted with each other. Was a fun thing to tune.

[Howardlong]

even better is : ditch trimmers. use dacs with eeprom on board. they are often cheaper than trimmers ...

i'm afraid that would work only for a very small subset of cases vast majority of cases require a trimpot and nothing else.

A long time ago I saw a graph of decades vs number of adjustments in a companies products.

1960s   1000 adjustments
1970s    100 adjustments
1980s      10 adjustments
1990s         1 adjustment

Good design and a little digital control can solve most issues.

I did design a diplexer that had 48 adjustment screws that all interacted with each other. Was a fun thing to tune.

Agreed, the last two RF designs I've designed have zero hand adjustments, and the most recent has an end-to-end integrated self-test for use in production that identifies each of about two dozen signal paths across five decades of frequencies, that saves masses of time. The only thing it doesn't test for is acceptable phase noise and whether the RF connectors are physically OK. I do those last two tests myself.

[David Hess]

1960s   1000 adjustments
1970s    100 adjustments
1980s      10 adjustments
1990s         1 adjustment

2000s   The integrated lithium memory backup batteries die rendering your 1990s instruments into doorstops.  The manufacturer offers to sell you new ones since they are unsupported and the calibration software was never made available to end users.

[Rick Law]

Trimpots with their 100-turn life cycle really is for occasional adjustments only.

If it is occasional, throwing a digital potential meter at it seems an overkill.  On the other hand, a design that uses a 100-turn trimpot for frequently-used adjustment is probably a design not worth fixing.

[FrankenPC]

Free idea for Bourns and other trimmer manufacturers: use Torx screws 

Then we will need twice as many trimming tools.

http://xkcd.com/927/

That XKCD comic explains just about everything wrong with standards from electronics to plumbing.