Hi - does anybody know if there is a measuring tool available (verniers or micrometer, preferably digital) that can directly read out scale dimensions? I read that PFM offered one years ago but haven't seen anything current?
Would be very handy sometimes to be able to measure something from the scrap box in "real world" size, just to check if it would fit a current build.
I'd have thought that digital verniers would be relatively simple to have one or more alternative scalings built into their display electronics.
Thanks,
Bob
Found this in a search of the forums.
http://cs.trains.com/mrr/f/88/p/261157/2938320.aspx#2938320
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Years ago I purchased an HO scale dial caliper, on eBay, manufactured by General Tool. Its plastic, so its not as durable as a regular caliper. The stock number, 1401, isn't listed on Generals website. The included paperwork is dated 1994. I didn't see any currently listed on eBay and there are no completed listings. An inexpensive dial or digital caliper and a conversion chart might be your best bet.
I use a digital caliper and this chart http://www.urbaneagle.com/data/RRconvcharts.html
I have been using a Mitutoyo Digital Caliper for the last 10yrs. Not a problem with it...but You pay for it...highly precision instrument that reads MM, IN. and Fractions. Really no need for a chart. I used to build/rebuild Diesel engines and race car engines so I needed a precision one so the expense was justified. For Modeling purposes You can get a pretty good one for under 30 dollars, even stainless steel ones....stay away from plastic ones if You can. Here is a You-Tube video of some You can review:
https://www.youtube.com/watch?v=1yqZx_FNbSs
Take Care!
Frank
There are a zillion smartphone and tablet scale conversion apps, so just get a regualr one and punch in the numbers. Mitutoyo is good stuff, you'll find their stuff in many precicion machine shops. That level of prcision is a bit more than $30 though. But then one doesn't need to measure to the nearest 10th when working with scale models. accuracy to the nearest thousandth is plenty.
I'll never forget an older issue of MR with a column on calipers, recommending the digital ones so you didn't have to keep track of how many times the hand spun around in the analog type..... I think that was by Lionel Strang. Hopefuly he's learned how to read a dial caliper by now. I was just shaking my head.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Re copied from the linked thread, and I should clarify. The made in China Starrett costs about the same as an Athearn RTR Diesel. The Made in USA version costs as much as a sound equipped Athearn Genesis.
On page 69 of the OCT 1997 issue of MR is a table to convert real dimensions to HO scale in an Excel spreadsheet. (HO 1" = .011") You can do the same with a spreadsheet program and print one out for easy reference.
Note:
I bought a plastic General 6" Dial. It cost $30. It is not accurate, and not very useful as far as I am concerned. I went to Starrett's website and bought a steel 6" dial caliper (3202-6). It is accurate to within a .001". Its made in China. If thats not your bag, an extra $100 buys you a dial caliper made in Massachusetts. Plus its made out of steel. It costs about the same as an Athearn RTR locomotive (without sound). In my book the Starrett was a better purchase.
http://www.starrett.com/metrology/metrology-products/precision-measuring-tools/slide-calipers/Dial-Calipers#currentPage=1&displayMode=grid&itemsPerPage=24&sortBy=listprice/asc
I don't use digital precision measuring instruments, because dial and vernier dont have batteries that have to be replaced, and I prefer to not have to fiddle with my tools to get them to work.
The Chinese made ones at Harbor Freight are fine enough for model work, they are metal, not plastic, and fairly inexpensive. They have dial and digital, I have one of the digital ones. Haven't used it in some time (it's been in my tool box for 3 years since I moved) and the batteries are still good.
I've got a Mitutoyo digital 1" micrometer that reads to 0.0005" from my last job and that worked great for stuff under an inch. Last year I bought a 6" dial caliper from Harbor Freight and even though it's a cheap one, it's surprisingly accurate. With a dial, I can see the pointer between the 0.001" graduations so it's accurate to around 0.00025" (a quarter of a thousandths)...plenty good enough for modeling. I'd rather have a nice dial caliper, not my cheap HF one, but it surprised me how good it was (a Mitutoyo caliper feels MUCH better but is easily over $100).
The batteries in my digital mike go dead in about a year (it has an auto-off feature) but the dial caliper never needs batteries and keeps it's measurement nicely. I still use the mike even though the batteries are dead because it also has markings on the barrel. Learn how to read one and you'll have that skill for life...even when the batteries die. :)
Buy the best tools you can afford, they'll last for ever and make your job that much easier.
http://delray1967.shutterfly.com/pictures/5
SEMI Free-Mo@groups.io
delray1967 ...even though it's a cheap one, it's surprisingly accurate. With a dial, I can see the pointer between the 0.001" graduations so it's accurate to around 0.00025" (a quarter of a thousandths)...
...even though it's a cheap one, it's surprisingly accurate. With a dial, I can see the pointer between the 0.001" graduations so it's accurate to around 0.00025" (a quarter of a thousandths)...
You're right, it's readable, not necessarily accurate. I just meant with a dial needle, you can see about where the needle points to, about half way between the graduations, or just a hair over or under a graduation. My mike reads 0.0000 or 0.0005, it might be just at the sensor boundary (which would be around 0.00025?) but I'd never know it; it only blinks from zero to a half thou instantly. It's just another (small) benefit of analog things (dead batteries drive me crazy.lol).
I haven't had it calibrated officially, but the small shop I worked at 10 years ago made high precision carbide gages. I didn't make those just ran the cnc's that made carbide endmills, so sometimes there'd be pretty accurate scrap I would salvage (shanks were centerless ground to 0.0002).
When taking a reading with the dial calipers, I take it three or four times and average the reading (slight pressure can compress whatever I'm measuring and the jaws could also flex (something a good 'name brand' set of calipers wouldn't tend to do. The readings are never more than 0.0005 off. The shop I worked at had a Starrett 8" dial caliper that was super nice (smooth as silk) but for hobby work, all I could justify buying is something that can read to 0.001. I am (surprisingly) pleased with the cheap (Pittsburgh?) calipers (for hobby use).
An affordable way to check for caliper accuracy:
Use a GOOD quality feeler gage (note the big letters: "GOOD"). I've got one from back when people had to check spark plug and points gaps. I spared no expense. Mostly because feeler gages, at the time, never got really expensive, anyway. It goes from .0015 up to .025. I just checked my caliper and it was OK. That is, being digital, the numbers on the screen matched the numbers on the gage leaves. And try not to cheat by weaseling on how hard to close the jaws.
Someone else has suggested using loose balls from ball bearings. Now, those don't come with numbers etched onto them, so you may be making unwarranted assumptions, there. But they do go much bigger than feeler gages. But, whatever dimension they were SUPPOSED to be, you can pretty much count on that as being true.
For us/we folks, probably the only time we need accuracy in the thou range is, coincidentally, in the feeler gage range. Out in the 5 and 6 inch range, not so much. Just a thought, there.
However, if you want to go further, do an Amazon search for "gage block". There's quite a selection, from a $15 1-2-3 block that's a thou off in one dimension to some Mitotoyo blocks that are somewhere close to absolute perfection.
Ed