Digital Linear Measuring Devices

[Ben]

What is the principle used in digital linear measurements?
I want to build a 30 inch measurement tool with a digital readout for
height
adjustment on a bandmill carriage. Are there suppliers of plans, kits,
components etc.
Thanks, Ben

 

[GPG]

Resolution? accuracy?

 

[Ken Moffett]

What is the principle used in digital linear measurements?
I want to build a 30 inch measurement tool with a digital readout for
height
adjustment on a bandmill carriage. Are there suppliers of plans, kits,
components etc.
Thanks, BenDo a google search for LINEAR DRO

 

[Spehro Pefhany]

What is the principle used in digital linear measurements?
I want to build a 30 inch measurement tool with a digital readout for
height
adjustment on a bandmill carriage. Are there suppliers of plans, kits,
components etc.
Thanks, Ben

Lots of technologies for that distance range- optical (scales),
magnetic, linear pot, capacitive, rotary encoder+rack and pinion, etc.
etc. What's a "bandmill"? Some kind of big wood sawmill bandsaw thing?

If so, you probably don't need machine-tool accuracy/resolution, but
have a nasty environment. You could probably adapt a magnetic machine
tool DRO with a 36" scale- cost should be maybe $800 USD for a "kit"
(display + scales).

Best regards,
Spehro Pefhany

 

[S.M.Taylor]

What is the principle used in digital linear measurements?
I want to build a 30 inch measurement tool with a digital readout for
height
adjustment on a bandmill carriage. Are there suppliers of plans, kits,
components etc.
Thanks, Ben

Interfacing details for the Chinese DRO are widely available. There is a
Yahoo group
http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/?yguid=47656649

With a files area containing the details you need. The Chinese DRO are
available over 1 metre long.

Personally, a DRO on a bandmill sounds like overkill. I think a wire
pulley /optical or hall encoder would do well, for the 1/32 " accuracy
you probably need.

Steve

 

[S.M.Taylor]

Spehro Pefhany wrote:
.. What's a "bandmill"? Some kind of big wood sawmill bandsaw thing?

Yes, for trees ! Big, scary machine....

Steve

 

[Tony Williams]

Spehro Pefhany wrote:
What's a "bandmill"? Some kind of big wood sawmill bandsaw thing?

Yes, for trees ! Big, scary machine....

Scary as hell. I only ever did one job in a sawmill,
never again. It was also on the plank-cutting bandsaws.

Two huge bandsaws running alongside each other, one fixed
and the other on a moving carriage, moved as required for
the desired plank width. About 12 tree trunks circling on
a carousel, and each time a trunk came around it had another
plank sawn off it. You didn't work 'on the saw', you worked
inside the saw, standing in the carousel, trying to do the
adjustments, whilst dodging the circulating tree trunks.

The moving bandsaw was moved with a large leadscrew and
turns-counter. At each power-up the saws closed together,
(onto a stop switch), and the turns-counter was Zeroed.