HO Digital caliper ?

Model Railroader General Discussion (Model Railroader)
1

Quick question. I have reviewed some of teh digitial caliper but it is not clear to me whether these can be set to measure in HO. For instance, If I wanted to measure a wall height of 8’-10" in HO scale, do the digital calipers have this capibility or do I have to still do the conversions first ?

Thanks in advance for your response

YGW

2

Are you talking about actual HO calipers - i.e. calipers that will measure 1" but tell you it’s 87.1"? Or, regular calipers that will do that calculation for you?

Tom

3

If they can do HO measurements, I am sure they will specifically declare that. Starrett, for one, does not declare that.

I’m in the middle of a project now, and I convert everything to “real” dimensions in .001". Which is exactly what a caliper will do. At least, a non-metric.

I sure wouldn’t MIND a caliper that output both “real” dimensions and HO. But I don’t think anyone makes a good one that does that. And I don’t want a not-good one.

Ed

4

I think in the last 2 months we had this conversation and someone said there used to be a converting calipers.

It wouldn’t be hard to set up an spreadsheet to do the conversion or even a calculator app on your phone or computer.

The cheap Harbor Freight calipers used to burn through batteries, they are better now. They are plenty accurate for our purposes.

For 8’ 10 …Convert to inches 8’x12"= 96"+ 10" and it = 106" to convert that to 1/87 multipy 106 x 0.011494 and you need 1.22 ruler inches to be 8’ 10" in HO land

0.011494 is your conversion factor for HO to convert the real dimension in inches into scale inches

5

I read not to long ago in the MRH forums about TMTV HO Scale Calipers.

Do some searching.

I believe it is TrainMasters TV.

I recall seeing a HO scale caliper at one time with Micro Mark on it but Micro Mark no longer shows it. Not enough demand from what I found out.

Echo Mountain Model Products sells one for $58.00 and it does different scales.

Rich

6

I asked that same question here a while back,3/4mts ago.Was told they were no longer being made, anyway I couldnt locate one.

Someone,can’t recall whom, posted a link in that thread, to a site that had spreadsheets to covert all kinds of stuff. Thanks to who ever that was.

With tose spread sheets and my 20$ caliper its quite simple to figure out what I need

7

I deal with this all the time. “Spreadsheets”? Right.

I’ve got me a “pocket calculator”. From the olden days. It’s not blue tooth or wireless enabled. And it can’t be hacked.

I just enter my number, multiply or divide as necessary; and I have my answer.

Sorta like back in 4th grade. You DID do the homework, didn’t you?

Ed

8

4th grade pocket calculator? I think we were barely past the personal chalk board stage back then.[swg] I think I was in grade 8 or 9 before I saw my first Texas Instruments calculator.

Dave

9

General made a dial calipers that reads out in HO feet and inches. I have one and it is very useful, but I think it is now several years since General offered it. It is not digital but “analog.” I think it also can be read out in O (1/4" scale) but there the conversions are much easier using regular calipers and other measuring devices.

Dave Nelson

10
11

Thanks everyone for the replies. Very helpful If anyone has the link to the spread sheet mentioned I would greatly appreciate that link.

Thanks

YGW

12

I still have my slide rule…somewhere.

13

[quote user=“7j43k”]

I deal with this all the time. “Spreadsheets”? Right.

I’ve got me a “pocket calculator”. From the olden days. It’s not blue tooth or wireless enabled. And it can’t be hacked.

I just enter my number, multiply or divide as necessary; and I have my answer.

Sorta like back in 4th grade. You DID do the homework, didn’t you?

Ed

4th grade? I was out of high school, married with kids before pocket calculators were affordable.

When I need to know how big a thing is in HO, I use my digital calipers,witch tells me in nice big numbers,I then turn to my SPREADSHEET hanging onthe wall to my right.In less time then it took you to smart off I have my answer

14

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 a 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.

Once I get my workshop set up (still unpacking) I plan to create one of those spreadsheets, print and laminate it. Then I’ll just thumb tack it to the work bench.

Ed (7j43k),

I didnt do my homework, I just took the tests and passed the classes once I figured out I could get away with it.

15

I am certainly not saying I had a pocket calculator in fourth grade.

In the above, I say that I use one NOW. It, admittedly, is from the “olden days”. But not THAT olden. More like “shortly after they became commonly available and dirt cheap”.

THEN I start referring back to fourth grade. Notice that I shifted to past tense. That part is about knowing how to multiply and divide.

Ed

16

At the current time, I am working on building an NW2 in HO scale. Dimension in HO feet and inches are pretty useless. I convert any of those dimensions (wheel diameter is an obvious one) to decimal inches. 40" quickly becomes .459", because it is more useful. And, of course, it reflects the true diameter of the model wheel. Mighty handy. Say, for example, if you wondered what size brass rod to use to make one (1/2" would work). Neither do they sell brass rod in HO feet/inches.

Note also that, for a wheel in HO, NMRA’s RP-25 is also in decimal inch dimensions. Not HO feet/inches.

One additional compelling reason is that my machine tools are all in decimal inches. I am currently in the middle of machining a fuel tank on my milling machine. EVERYTHING is in decimal inches.

What I’m trying to get at is that I don’t see much use in an HO caliper. I suppose if I had one, I might find an occasion to use it. But I think it would be rather rare. And, remember, those dimensions pretty quickly would be turned into “regular” dimensions. At least, if I were doing model building.

I think it far better to get a GOOD caliper in basic decimal inches first. THAT one will be more useful overall. You, of course, might find you still have a yen for an HO one. These things happen.

Ed

17

I totally agree with you. The only uses I could see is if you were verifying the dimensions of a model or making a scale drawing working from the model, or if you were checking the dimensions of a detail part.

A HO scale dial caliper is entirely too situational a tool to use for me to spend money on it.

18

I seem to have mislaid mine. It’s not where I left it. Well, it actually might be. Where I left it. But it’s not where I THINK I left it.

But I have my father’s. He got it to go to college on the GI Bill. It’s a big ole magnesium Pickett Model 4. I see on Ebay they’re sharply discounted.

Ed

19 
                   HO Scale Measurements
 HO ft\in     0     1     2     3     4     5     6     7     8     9    10    11
     0     0.00  0.01  0.02  0.03  0.05  0.06  0.07  0.08  0.09  0.10  0.11  0.13
     1     0.14  0.15  0.16  0.17  0.18  0.20  0.21  0.22  0.23  0.24  0.25  0.26
     2     0.28  0.29  0.30  0.31  0.32  0.33  0.34  0.36  0.37  0.38  0.39  0.40
     3     0.41  0.43  0.44  0.45  0.46  0.47  0.48  0.49  0.51  0.52  0.53  0.54
     4     0.55  0.56  0.57  0.59  0.60  0.61  0.62  0.63  0.64  0.66  0.67  0.68
     5     0.69  0.70  0.71  0.72  0.74  0.75  0.76  0.77  0.78  0.79  0.80  0.82
     6     0.83  0.84  0.85  0.86  0.87  0.89  0.90  0.91  0.92  0.93  0.94  0.95
     7     0.97  0.98  0.99  1.00  1.01  1.02  1.03  1.05  1.06  1.07  1.08  1.09
     8     1.10  1.11  1.13  1.14  1.15  1.16  1.17  1.18  1.20  1.21  1.22  1.23
     9     1.24  1.25  1.26  1.28  1.29  1.30  1.31  1.32  1.33  1.34  1.36  1.37
 HO ft\in     0     1     2     3     4     5     6     7     8     9    10    11
    10     1.38  1.39  1.40  1.41  1.43  1.44  1.45  1.46  1.47  1.48  1.49  1.51
    11     1.52  1.53  1.54  1.55  1.56  1.57  1.59  1.60  1.61  1.62  1.63  1.64
    12     1.66  1.67  1.68  1.69  1.70  1.71  1.72  1.74  1.75  1.76  1.77  1.78
    13     1.79  1.80  1.82  1.83  1.84  1.85  1.86  1.87  1.89  1.90  1.91  1.92
    14     1.93  1.94  1.95  1.97  1.98  1.99  2.00  2.01  2.02  2.03  2.05  2.06
    15     2.07  2.08  2.09  2.10  2.11  2.13  2.14  2.15  2.16  2.17  2.18  2.20
    16     2.21  2.22  2.23  2.24  2.25  2.26  2.28  2.29  2.30  2.31  2.32  2.33
    17     2.34  2.36  2.37  2.38  2.39  2.40  2.41  2.43  2.44  2.45  2.46  2.47
    18     2.48  2.49  2.51  2.52  2.53  2.54  2.55  2.56  2.57  2.59  2.60  2.61
    19     2.62  2.63  2.64  2.66  2.67  2.68  2.69  2.70  2.71  2.72  2.74  2.75
 HO ft\in     0
20

http://www.urbaneagle.com/data/RRconvcharts.html

this is what I use