Newbie Question about Schumatech DRO
 

Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?

Thanks all

Dan wrote:
Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?

Thanks all

i bought Chinese DRO's as shown in:
http://www.shumatech.com/support/chinese_scales.htm
I bought them as a kit with the readout and all I had to do was install
and plug in the wires.
As far as I can tell the accuracy is OK, with a resolution of .0005"
and it compensates for backlash in the machine. There is a button that
will rezero the reading at any point but I have had a lot of trouble
with the scales losing synchronization with the readout due to the
flimsy nature of the electrical connection. When this happens you must
take out the batteries and leave them out for 1 minute, then replace.
Someone has suggested soldering the connections together but this would
be difficult as they are encased in plastic.
The battery covers and the contacts are very poorly made and have given

me much trouble. The contacts that the battery touches are .005" thick
and I had one break off when replacing the battery. It was replaced by
the vendor but I feel that These Chinese scales arev too pooly made to
bother with.
Engineman

wrote:
and it compensates for backlash in the machine. There is a button that
will rezero the reading at any point but I have had a lot of trouble
with the scales losing synchronization with the readout due to the
flimsy nature of the electrical connection. When this happens you must
take out the batteries and leave them out for 1 minute, then replace.
Someone has suggested soldering the connections together but this would
be difficult as they are encased in plastic.
The battery covers and the contacts are very poorly made and have given

me much trouble. The contacts that the battery touches are .005" thick
and I had one break off when replacing the battery. It was replaced by
the vendor but I feel that These Chinese scales arev too pooly made to
bother with.
Engineman

There's no reason to use batteries, when one can supply
the power via the connector.. The connector pins are :

1. - power
2. clock
3. data out
4. + power

So, in my setup, I supply the power through this
connection and don't use any batteries. I have
soldered wires of a cable directly to the connector
of the caliper - it is easy when one takes away the
plastic cover of the electronics of the caliper.
I couldn't find connectors anyway, so soldering was
only option.

"Losing syncronization" is weird, as the scales
(calipers) send their position syncronously - about
10 times per seconds in slow mode - the display electronics
just wait for a new reading, convert it to displayable number,
and start waiting for next reading.. So if there is
connection problem, just reconnecting should make it work
again. I can't understand why one would need to switch off
for 1 minute - definitely not because of calipers.

Of course, I have no experience with the product
mentioned above - I have my own electronics for
reading the calipers. But the principle of operation
has to be the same.

Kristian Ukkonen.

You've got it right. One of the great things about a dro is that
backlash goes away. The backlash is in the screw/handwheel, moving back
and forth in relation to the table. The dro measures the table directly.
So if the table doesn't move (while you're taking up the backlash), the
dro doesn't measure any motion.

Steve

Dan wrote:

Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?

Thanks all

"Dan" wrote in message
...
Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?

Thanks all

IMHO for the cost of most decent DROs you can almost convert the machine to
CNC. Of course depending on skill level, bargains found, and current
machine.

--
Chris

If you can read this, thank a teacher. If it is in English, thank a
soldier. If it is in ebonics, thank your Congressman.

Dan wrote:

Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?

Thanks all



Maybe I didn't understand what you were asking about backlash, but I
still think that for side milling you should approach the reading you
want from a direction the mill will "push against" when you start
cutting. To do otherwise invites dimensional disaster, particularly if
you can't or don't lock the slide before starting the pass.

Jeff

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Dan wrote:
Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned about
backlash when using a DRO or does the scale compensate for it. Seems as
though the DRO gives actual position and Backlash is no longer a problem?

Fo those of you who have built this DRO before, is this a project someone
with little electronics experience can do?


Yes, If you run into a problem just go on the web site & someone will
walk you through your problem. Mine works great. I soldered the wires on
HF units.
Total cost with 3 scales $225.00

Thanks all

Jeff Wisnia wrote:

Dan wrote:

Wanting to add a DRO to my mill/drill (RF30 clone) and am considering
theSchumatech DIY DRO. My question is do you have to be concerned
about backlash when using a DRO or does the scale compensate for it.
Seems as though the DRO gives actual position and Backlash is no
longer a problem?

Fo those of you who have built this DRO before, is this a project
someone with little electronics experience can do?

Thanks all


Maybe I didn't understand what you were asking about backlash, but I
still think that for side milling you should approach the reading you
want from a direction the mill will "push against" when you start
cutting. To do otherwise invites dimensional disaster, particularly if
you can't or don't lock the slide before starting the pass.

Jeff

Good point, Jeff. When I had a mill-drill, I remember the experience
having a lot stronger words attached to it than 'dimensional disaster'.
I didn't break an end mill, but things were pretty exciting for a brief
moment.

Steve

Hi Dan,

I built one, was my first electronics project, actually purchased a
soldering iron just for the Shumatech Dro. Now, that said, it worked,
was not a fan of the "Chinese scale thing", Had a house fire, ruined
it, went out and purchased a 3-axis DRO (JENIX) with glass scales,
couldn't be more happy. It is much more sturdy than the Shumatech
model (no did intender, great product for those with the time and a low
budget). Now, that said, Scott Shumatech is a good guy, will help you
through the construction (as well as yahoo group fellows) and it is a
very powerful (from a software point of view) little unit. From what I
last read, he is expanding the PIC Basic chip memory to allow more
steps and, obviously, more features.

In a nut shell, ya get what ya pay for, cheap case, your time, but cost
only a few hundred bucks....

Hint, if you are going to do the Shumatech thing, go to
MyLittleMachineShop web site and order the scale to controller cables
now, they are usually backordered...they made the whole job alot
easier. I started off trying to make them and destroyed my first scale
in the process.

John

Hello John,

Aside from the flimsy case and Chinese scales, is there anything else you
don't like about the Shumatech design? I've just ordered a couple of boards,
am planning on installing them with JENIX scales. Might as well consider
suggestions for improvements while I'm at it.

Nobody on the yahoo group ever has anything but praise for the design, so
criticism is interesting/useful.

Thanks,

Adam Smith
Midland, ON, Canada

"CAMCOMPCO" wrote in message
oups.com...
Hi Dan,

I built one, was my first electronics project, actually purchased a
soldering iron just for the Shumatech Dro. Now, that said, it worked,
was not a fan of the "Chinese scale thing", Had a house fire, ruined
it, went out and purchased a 3-axis DRO (JENIX) with glass scales,
couldn't be more happy. It is much more sturdy than the Shumatech
model (no did intender, great product for those with the time and a low
budget). Now, that said, Scott Shumatech is a good guy, will help you
through the construction (as well as yahoo group fellows) and it is a
very powerful (from a software point of view) little unit. From what I
last read, he is expanding the PIC Basic chip memory to allow more
steps and, obviously, more features.

In a nut shell, ya get what ya pay for, cheap case, your time, but cost
only a few hundred bucks....

Hint, if you are going to do the Shumatech thing, go to
MyLittleMachineShop web site and order the scale to controller cables
now, they are usually backordered...they made the whole job alot
easier. I started off trying to make them and destroyed my first scale
in the process.

John

No criticism here either, great product...just more of a "toy" like
feel to it, a bit flimsy of a box, Chinese scales are, well, Chinese
scales. The box is something like 2.5"x4"x7" or something like that,
about 1/5th of the size(volume) and 1/10 the mass of the Jenix
box.....The software is great though, a lot of functionality, more than
the Jenix that I purchased.

If you are $$$$$ conscience, go for it, it's by far the cheapest way to
go as long as you don't bill your time out as part of the $$$$.
Personally, I used it as a reason to buy a Panavise, Soldering station,
static pad, etc.....

Go for it, you won't be unhappy, just not quite the "industrial/heavy
duty" feel to it.....

John