Hammer A3-31 Digital Read Out ... Imperial or Metric

[Girard Ibanez]

I bought the imperial one, used it for two days and sent it back for the metric. The acme thread that raises the table is 2 mm per rotation. It is a designed metric machine. If each turn of the handle was 0.100“ I would’ve stuck with Imperial.

The handle is an analogue. When you’ve played long enough in decimals of an inch and converting to mm, it just become second nature.

Matt,

I see the problem with the Imperial DRO ... If the acme threaded rod was 40 threads per 1 inch then this will be a true decimal inch change in height for every 1 revolution.

I sent an email to have my DRO order updated to the metric DRO.

Thanks

[Rod Sheridan]

I find it hard to believe there is not a switch to toggle from one system to the other as needed. I do not think the scales or reader heads are different. $10.00 HF calipers have the switch onboard.
Bil lD.

The gauges are digital mechanical, you have to purchase the correct one.........Rod.

[Jim Becker]

Jim,

I've been contemplating on this decision for the DRO, my Incra fence, Incra miter and Incra router lift are all imperial. It would be foolish for me to purchase the metric DRO for the jointer planer. I wish I had switched to metric during my initial purchase. As others have said, the metric system is much easier.

I am 56 years old ... it would be a massive brain adjustment.

That's perfectly reasonable....use the system you are best setup for. BTW, I'm about to turn 62 and started doing the metric dance about two years ago. I've "fallen off the wagon" slightly since getting my CNC because of the nature of the projects and the training materials, but I'll "correct" that at some point. I wish I would have switched to metric decades ago...

[Edwin Santos]

Edwin,

Yes it is dependent on the system I use most ... Imperial. Now that I know the DRO is in decimal inches, eg. I still have to convert 3/32" fraction to decimal inches. Hence why others prefer switching over to the metric system.

Thanks for all the replies ... I need to start by getting a metric tape ruler to grasp my old head and adapting the brain cells to metric.

You're right about the conversion of the decimal inches to fractions. I have a quick reference conversion chart tacked to the wall with conversions between fractional inches, decimal inches and millimeters. Now I know most of these conversions in my head, but if you worked in metric it would eliminate the conversion step.
I think adopting metric is a fine idea, but don't get hung up on the handle revolution thing. The purpose of the handwheel readout it to free you from reliance on counting handle turns, the readout should be the only thing you need to watch. Bottom line, if you work in metric or plan to change, get the metric handwheel, and if you work in Imperial, get that one. Either one will do what you want with great control and precision.

[Jim Becker]

You're right about the conversion of the decimal inches to fractions. I have a quick reference conversion chart tacked to the wall with conversions between fractional inches, decimal inches and millimeters.

I have a similar accommodation at my CNC workstation...a rodent pad with a fractional to decimal conversion chart. Like you, I know the most common ones at this point, but having the rest handy is, um...handy. LOL

[Prashun Patel]

I advise getting the metric.

The reason I went with metric is that it's easier to remember the exact mm number than the fraction (for me) when switching between set ups. As much as I try to gang my work so that I do all jointing then all planing, I always have a random piece that I need to re-plane to match the others. Remembering a discrete mm number is easier to remember and easier to set than imperial fractions. In my head, this is just more repeatable.

While I have always found fractional inches more intuitive than millimeters, that stops at 1/8". 16ths and 32nds are not intuitive for me. When thicknessing, I am usually not shooting for a particular number - but just to get all the pieces perfectly flat and consistent - and looking right to the eye. That means sometimes working between the convenient fractions. With mm, that becomes a non-issue for me.

I have a conversion sheet nearby so I can remember that 3/4" is about 24mm.

Also, if you happen to have a Domino, then it makes setting tenon thickness and stock thickness more intuitive.

[Girard Ibanez]

The gauges are digital mechanical, you have to purchase the correct one.........Rod.

The name Digital Read Out (DRO) is misleading. The word "Digital" translates to electronic readout. It should be mechanical digit read out.

[Rod Sheridan]

The name Digital Read Out (DRO) is misleading. The word "Digital" translates to electronic readout. It should be mechanical digit read out.

I'll disagree, to me digital means it has numbers that change. Remember the mechanical digital clocks or odometers in vehicles?

Now if it had said electronic digital then I would have agreed with you.


They were digital, not analogue...........Regards, Rod.

[Girard Ibanez]

I'll disagree, to me digital means it has numbers that change. Remember the mechanical digital clocks or odometers in vehicles?

Now if it had said electronic digital then I would have agreed with you.


They were digital, not analogue...........Regards, Rod.

Rod,

I stand corrected .... I looked up the definition. You are most correct.

[Prashun Patel]

I thought 'digital' in this context meant you have to use your fingers.

I don't think there's a strictly yes/no definition for 'digital'

[Chris Fournier]

There won't be a good answer here, they'll all be good answers. I'm Canadian, I used Imperial for the first 11 years of my life and then made the government mandated switch over to metric. As a Canadian I live next to the largest Imperial measuring country on Earth. I also machine metal as well as wood. Classical guitars are typically called out in metric, steel string and electrics in Imperial. My Minimax will allow me to choose systems and I use decimal inches. Personally I couldn't care less how much a rotation of my table feed moved the table if I have a digital readout, I'm working off the readout. I have long since memorised the decimal conversion for our fractions of an inch. I am used to and wired for Imperial in most things, no right no wrong. Use what you are comfortable with!

[John Kee]

Hard to rewire your thinking, like Chris said the change was mandated but for some of us the reprograming didn't work. I was 22 when it came in and to this day I think in Imperial and I set everything for imperial. Don't really care if somebody says its simpler and the rest of the blah, blah, blah. I work with wood and construction of it. Woodworking materials here are bought in imperial and all the dimensions are just metric that's been converted from imperial, that includes architectural drawings. This is forty years after the conversion. Use what your comfortable with and hook yourself up with a modern electronic DRO that can read both, not some dail that can randomly spin out of sync. Yes they will spin out of sync occasionally like I experienced on my 2008 A3-31. The machine is long gone and the DRO got binned and it was only $50.00 back then.

[Girard Ibanez]

Hard to rewire your thinking, like Chris said the change was mandated but for some of us the reprograming didn't work. I was 22 when it came in and to this day I think in Imperial and I set everything for imperial. Don't really care if somebody says its simpler and the rest of the blah, blah, blah. I work with wood and construction of it. Woodworking materials here are bought in imperial and all the dimensions are just metric that's been converted from imperial, that includes architectural drawings. This is forty years after the conversion. Use what your comfortable with and hook yourself up with a modern electronic DRO that can read both, not some dail that can randomly spin out of sync. Yes they will spin out of sync occasionally like I experienced on my 2008 A3-31. The machine is long gone and the DRO got binned and it was only $50.00 back then.

I was thinking on the same line .. Perhaps someone has added a digital Wixey height gage.

After considerable thoughts and reading on this thread, I am sticking to what I am comfortable ... back to imperial DRO. I can always change it later but for now going with my first decision.

[Curt Harms]

Definitely metric for 2 reasons

1) If you design your own stuff, metric is much easier as there are no fractions. Who would ever know if your shelf is 20mm or 0.75" thick?

2) Your machine is metric, one revolution of the planer elevation hand wheel is 2mm. If you're using the Imperial gauge, it's 0.078 inches. good luck with wrapping your head around that.

I have the metric gauges on both my A3 and B3, time to get with the 21st century and go metric.............Regards, Rod.

More than a few people in the U.S. will do as well with .078" as with 2 mm. I understand what you're saying and agree but a person is going to have to want to learn what 2 mm looks like. Old dogs, new tricks and all that.

[Rod Sheridan]

More than a few people in the U.S. will do as well with .078" as with 2 mm. I understand what you're saying and agree but a person is going to have to want to learn what 2 mm looks like. Old dogs, new tricks and all that.

I agree Curt, however I doubt if anyone could recognize 2mm or 0.078" without measuring.

That's what I find so odd, we've been metric since the 70's, yet when I'm at the supermarket buying lunch meat, people still claim they don't know whether they should buy 200 or 300 grams. I couldn't estimate whether that's 4 or 6 ounces, I just know that I buy 300 grams (approximately).

It's not because I need 78 grams per day or 0.78 ounces, it's just that I know 300 grams is about right for the number of sandwiches I'll make.

We measure almost nothing in our life, yet worry so much about the measurement system......Rod.