POTD- PROJECT OF THE DAY: What Did You Make In Your Shop Today?

I love the structural shunt!!

Here's a similar one I did for our First Robotics 10 slot charger. Yes, it will get some riv nuts soon
749987829fa20123f83e81b6b98c4efd.jpg


Sent from my SM-G715A using Tapatalk
 
Quick look at your metering and it is not good...

VRLA batteries do not like being overcharged.

Battery is full usually at 2.25 VPC or 13.5 volts.

Some chargers go higher resulting in equalize or bulk charging then drop down to float.

Reason for building our unit is just that, we have a 36 volt 5 Amp lead acid charger that is still showing the RED charge at 44 or so volts, when tested on some alarm batteries it would shift to green to indicate charge complete and maybe floating, have not retested on them yet.

The float charge should not exceed 0.1 % capacity in Amp hours, those look like 16 Amp hour batteries.

0.016 is 0.1%, if left at a higher rate they can Gass off when the pressure valve opens.

That size battery is often used in UPS and is rated for "Cycle Service" where it has a heavy load for short periods followed by high rate of charge to get ready for next cycle.

This matches your use, however cycle Service batteries are usually swapped out yearly while same battery in float service design life is 10 years.

If you do rapid charging for contests your batteries will loose both life and capacity.

The capacity part is critical in your application as you need every bit of available power.

Better to buy additional batteries and reduce charging stresses.

The cost of additional batterys rotating may have a lesser cost due to longer life than stressing singles.

Get the data sheet for your batteries and insure your charger stays within those guidelines.


Sent from my SM-G781V using Tapatalk
 
I wouldn't put much stock in the Volt readings... cheap-o.
These are sealed batteries. SLA.
I'm confident the $1k charger knows its business.
Yes, we only get a couple years out of them! I just built a tester to get a bit closer to our real loads that pulls 50 Amps! In competition we peak up around 200 Amps, and pull 1/4 to 1/2 the capacity in 3 minutes.
018c3d37a0eb525522c46dd834d4abc5.jpg
9a2f634e83d1793acf68ac82d1863a35.jpg


Sent from my SM-G715A using Tapatalk
 
Taday I replaced the X axis scale on my Ditron 80 DRO. I was never really happy with the slim 1um magnetic scale though it was sure tiny and nice physically. Inconsistent diameter mode readings were frustrating, and I found that if I could locate an error, blowing off the scale of ferrous chips/dust would make it disappear. I blame the design for exposing the edge of the mag strip, not fully covered by the stainless top strip.

But the new generation of Ditron scales completely encloses the magnetics with three sides by the aluminum carrier and on the mag side by the stainless top strip that slides inside the extruded carrier. I think this will be much better.

It’s an easier install than the older design, though every bracket and screw position is different. It’s in and linear calibrated, and against three 123 blocks, it’s as accurate as I can read the 0.0005 DTI.

I’ll report after I use it a bit.
 
Last edited:
Taday I replaced the X axis scale on my Ditron 80 DRO. I was never really happy with the slim 1um magnetic scale though it was sure tiny and nice physically. Inconsistent diameter mode readings were frustrating, and I found that if I could locate an error, blowing off the scale of ferrous chips/dust would make it disappear. I blame the design for exposing the edge of the mag strip, not fully covered by the stainless top strip.

But the new generation of Ditron scales completely encloses the magnetics with three sides by the aluminum carrier and on the mag side by the stainless top strip that slides inside the extruded carrier. I think this will be much better.

It’s an easier install than the older design, though every bracket and screw position is different. It’s in and linear calibrated, and against three 123 blocks, it’s as accurate as I can read the 0.0005 indicator.

I’ll report after I use it a bit.
How do you determine the calibration factor? Move the DRO the distance of a 123 block and divide the distance by the number of counts? I'm asking because I am trying to decode the output of a read head myself, for a home brew DRO reader. More accurately, I am trying to incorporate a DRO function into my home brew electronic lead screw controller.
 
How do you determine the calibration factor? Move the DRO the distance of a 123 block and divide the distance by the number of counts? I'm asking because I am trying to decode the output of a read head myself, for a home brew DRO reader. More accurately, I am trying to incorporate a DRO function into my home brew electronic lead screw controller.
You will need to find the technical data sheet, but in absence of that I'm certain the encoding are standardized. Here are some schemes for encoding to give you an idea:

Magnetic-Tape-Examples-768x401.jpg


Heidenhain-Reference-Marks.gif
Combined%20scale%20(incremental%20%2B%20absolute).jpg
 
How do you determine the calibration factor? Move the DRO the distance of a 123 block and divide the distance by the number of counts?
The DRO has a calibration routine in it, so basically all you do is move a certain distance, your choice, and tell the DRO just how far that was. The DRO does the math and applies a linear correction factor to all future measurements.

I use a couple 123 blocks for a 6” baseline, and a DTI to get as accurate position as possible.

The math is something like (DRO reading - Actual travel) / Actual travel = correction factor.
 
The DRO has a calibration routine in it, so basically all you do is move a certain distance, your choice, and tell the DRO just how far that was. The DRO does the math and applies a linear correction factor to all future measurements.

I use a couple 123 blocks for a 6” baseline, and a DTI to get as accurate position as possible.

The math is something like (DRO reading - Actual travel) / Actual travel = correction factor.
I am trying to use the magnetic scales that I have, but using my own software. Pretty much a diy DRO. So I don't get the advantage of any built in calibration routines. I have to write the routines myself. Hoping it is a simple correction factor. Can I presume the main incremental scale is fairly linear, so a simple calibration factor is sufficient?
 
You will need to find the technical data sheet, but in absence of that I'm certain the encoding are standardized. Here are some schemes for encoding to give you an idea:

Magnetic-Tape-Examples-768x401.jpg


Heidenhain-Reference-Marks.gif
Combined%20scale%20(incremental%20%2B%20absolute).jpg
For the cheap scales that I have, and the even more ancient 1/4" high 7 segment LED displays, I have to believe it is the simplest incremental scale. Hoping it is linear so a simple correction would suffice. Guess I could stack some 123 blocks and see if the same calibration factor applies.
 
Back
Top