Going to expand this thread a little......
GENERAL ADVICE:
Unless you are going to use all the functions and desire accuracy of higher end instruments I would suggest
one don't spend a lot and be practical on intended use of what and why you buy something. There are many
different "toys" available, some worth buying new because of todays technology and associated cheap price.
I will add that a specific tool even if used once a year purchased at "steal" price could worth it's weight in
gold when your doing something. Any electronic used "toy" should be considered faulty, but, an attachment
may worth the chance. Know the instruments you are buying, be patient and you can have a lot of practical use
"toys".
SO, that said and it's just my opinion,
Volts,Ohms,Current,continuity Multimeter................
Have a Fluke 87 & 77 and mostly use the 77. Another cheapo one is in the auto tool box. One can get a lot for
your money these days.
A dual trace scope can come in handy and you can find some used ones reasonably priced. Functionality,
bandwidth, sensitivity, etc all add to the cost. Have two of them 20 & 400 Mhz, don't use either of them
often.
Then you have temp measurement........
You can get probes which work with the higher end multimeters, but, individual
digital hand held infared or thermometers with probes are nice also. All depends on what
one is going to do with it. An infrared nonconctact with emissivity adjustment is a very usefull item.
There are manny available today resonably priced.
Then you have RPM measurement........
This is one thing that you should have. There is nothing wrong with contact speed indicators ( Biddle,
Hassler, etc ) because if you can't shut the rotating item off it may be the only way to measure rpm and they
are quite accurate. The digital tach's are just great to use and you can get one for cheap!
Then you have inductance and capacitance measurements.........
Comes in handy if you want to know some characteristics of the unknown stepper, but, the average guy
won't be interested or use one, and yes some of the higher multimeters provide these functions.
Then you have you AC amp measurements.......
A clamp on meter is usefull to measure current draw.
So there are a lot of "toys" out there and can find some real bargains if they take their time.
Here is some prices and toys and most are handheld:
RPM MEASUREMENT:
- Digital Tach DT-2234C ~ $11 on EBAY today ~ very accurate and just great for checking or setting rpm.
I modified a contact strobe attachment from a high end but broken digital tach $3 from flea market
so it can be used on contact.
- Biddle, Hassler or other mechanical brands - why bother when you can buy the above today
Multimeter:
- Fluke model 77 - $10 from a pawn shop ( I usualy have a few batteries with me so i can test stuff when
looking for stuff. )
Dual Trace Scope
- B&K 25 Mhz with probes - Flea market and could check the trace before purchase ~ $50
AC CURRENT CLAMP METER
- Sperry digital with leads/case - and also has typical multimeter function ~ $12 ( took a chance
didn't have a battery with me to test, the leads were worth the money ) like new and works fine.
TEMP MEASUREMENT
- Whal - digital infrared nonconctact with emissivity adjustment ~ $15 Garage sale
- VMR Taceable Digital - Data logging with probe and case ~ $5 flea market special and like new!
TORQUE MEASUEMENT
- Look for In oz torque wrench, beam type is ok 0 to 28, or 1/4" drive adjustable say 20 to 100,
but my best find was an actual small calibrated Gauge 10-120 in oz / reversable and very accurate.
That's what's used to find the affect of bearing preload or gib adjustment on min axis torque and backlash.
In summary you can have a lot of use full toys for under $100.
FWIW and may your dumpster diving adventures be fruit full,
RICH