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Would anybody like to beta test a rechargeable battery system for Renishaw OTS probes

corednc

Aluminum
Joined
Sep 3, 2019
Location
East Coast
Visited a friends shop in late 2019 and saw all the 1/2 AA batteries from their probes that they discard in a year. They get approx 6 months out of a pair and less if the machine is lights out (more tool probing). With 48 mills they go through about 250 batteries a year on just the table probes alone.
This seemed like a waste of money, material, etc. so I created a rechargeable battery system for the 1/2 AA OTS probes. It screws into the back of the OTS probe in place of the battery cover and provides power via a single rechargeable li-ion battery. You should see no difference in use from the 1/2 AA batteries, it even signals the probe when the battery is low so that the low battery lights on the OTS and OMI/OMM work as they should. If you forget to charge the battery in time, 10 minutes on a charger and you are good to go for the rest of the day and maybe more, no more scrambling to overnight ship a few batteries with a machine down.

I have a few beta units remaining so let me know if you are interested. Please note that the beta units that remain have some cosmetic issues (spots on the anodizing and things like that) but they are all fully functional, batteries included.

on_probe.jpg
 
It actually uses a 21700 battery but you can find a charger for under $10 from the usual places. I prefer the vapcell s4, usually about $35 but well worth the extra.
 
If 10 minutes on a charger gets you through the rest of the day, how long does a full charge get your friend running lights out? How does the life of this setup compare to that of running the standard batteries?
 
This is a neat idea, but why TF would a shop with 48 mills continue to buy them with the stupid 1/2AA size probes? The full AA size OTS is a direct swap... :nutter:

The full size system is also a lot smaller than this, and lasts months running 24/7 in our environment with tool breakage running on every tool.

Seems like a creative solution to a problem that shouldn't really exist.
 
If 10 minutes on a charger gets you through the rest of the day, how long does a full charge get your friend running lights out? How does the life of this setup compare to that of running the standard batteries?


Sorry I was not clear, when I said "you should see no difference" between this and the standard batteries I meant the runtime of the OTS will be same with this set up as with the 1/2aa. So if you get about 6 months with your 1/2aa batteries you will get about 6 months with this. My friend gets about 2 months running lights out with the 1/2aa batteries and about the same with the rechargeables.

When it comes to lithium derived batteries there is about a 4x difference in energy density in single use vs rechargeable batteries so you need to increase the size of the battery to compensate, there are also some other differences like output voltages that you need to contend with.
 
why does anybody need a wireless probe? Pallets?

Dare I say most moving table machines have wireless tool probes? Certainly most new machines from the big builders.

One less thing to deal with. The optical interface is already there for the spindle probe, so might as well use it. Plus some of us like to move it to a new spot (or yank it off the table) from time-to-time.
 
It is quite amazing, that Renishaw are still "pumping" the OTS1/2AA product. The lithium 1/2AA batteries are expensive, difficult to find, and not all off them can work with the device (just see the proper battery type "bulletin" attached to operation manual). The newer OTSAA does the same job, using not restricted, widely available cheap batteries. So why not to discard the older product. Maybe the words "sorry, we've made a mistake" do not exist in their vocabulary.
 
This is a neat idea, but why TF would a shop with 48 mills continue to buy them with the stupid 1/2AA size probes? The full AA size OTS is a direct swap... :nutter:

The full size system is also a lot smaller than this, and lasts months running 24/7 in our environment with tool breakage running on every tool.

Seems like a creative solution to a problem that shouldn't really exist.

Unfortunately there is not always a choice as to what size OTS you get, it is usually up to the machine tool builder. AFAIK the AA size OTS is not an option for Haas machines (certainly was not for me) and swapping it out after the purchase is approx $2500.

I think the biggest problem is that even if you are using the 1/2AA or the AA version they are still single use batteries which seems like such a waste given the li-ion rechargeable options that we have today. Single use batteries end up costing more and creating more waste than something like this. When I looked into it, even with my very modest production I spend about $65 per milling machine per year on single use batteries and dispose of at least 9 batteries per mill per year.
 
I like this idea, good luck with it.
We only have one OTS probe here, it uses the 1/2aa batteries, and it doesn't get a lot of use compared to you 24/7 people.
Still, every time I swap out the batteries I think "what a waste."
There's no reason the table probe on a little DT-1 can't be wired to avoid this.
 
When I looked into it, even with my very modest production I spend about $65 per milling machine per year on single use batteries and dispose of at least 9 batteries per mill per year.

We haven't bought (or thrown away) AA or AAA batteries in years. Quite a while back I bought about 40 of these in bulk packs and a charger, then put them in one of the consumables drawers in the tool crib. IIRC they have more capacity than normal single-use batteries as well.

https://www.amazon.com/Panasonic-BK...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
 
Just a little update, beta tests went fine so I decided to pull the trigger on a production run.

Lessons learned
[1] The final device contains 4 stainless steel springs but in the beta version the largest spring was epoxy coated spring steel with the ends slightly exposed so that it could conduct. Had to make the change because even with the primary liquid being coolant, bare steel will still rust given the right conditions.
[2] At my spring supplier for stock stainless there is a 11x price difference if you buy 1000 pieces and a 2x difference if you buy 100 pieces. I can only assume they are made to order and the set up time must be large or I am in the wrong business.

Even the simplest things have microcontrollers and software that needs to be programmed and doing things one by one is a pain. To make things easier you generally create a bed of nails which is another circuit board that connects to your production board through a set of spring loaded pogo pins. The bed of nails can then program and test and adjust all of your production boards at once. Add some downward pressure and in a little less than 4 minutes all boards are programmed and ready to go.
The pictures don’t include the automated test equipment that connects to the bed of nails and I botched the bed of nails PCB layout so I had to pull out the magnet wire to make things right.
 

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I'd be curious about a rechargeable sled for RLP40 probes. The issue I have from time to time is the battery compartment gasket leaking, then corroding the contacts though.
 
It has been a while since I updated this thread. Sorry, I was unprepared for the semiconductor shortage and I had to put this on the back burner for a bit. Project is almost done, just trying to pull things together.


disassembly.jpg


11 machined parts
5 o-rings
3 circuit boards
3 springs
4 different adhesives

The biggest issue with this product is the assembly, it is more complex than screwing things together because it is designed so the electrical current from the battery is isolated from the case (The only live parts are the spring loaded tips). Also it is designed to keep moisture out while also being able to handle any moisture that may accidentally get in.
To save time on assembly I was able to remove all the press fit parts in favor of screw threads and a retaining clip. Using a 0.001" shim to slip an o-ring past some threads was too time consuming and error prone.

It would be interesting to hear experiences having your product assembled by another company when the assembly is finicky.
 
First let me say a big thank you to those of you who participated in the beta test of this product, I appreciate the feedback. I also want to say sorry for the delay, the semiconductor shortage caused some issues.

This product ( the renicharge ) is now in stock and ready to ship. Free charger included while we have them in stock. Any info and technical details you need should be on the website Renicharge | corednc but feel free to contact.

ren_mult.jpg
 
Why is this better than regular rechargeable batteries?

The 1/2 AA rechargeable batteries that would fit in the probe have a fully charged voltage of 4.2 volts and a typical capacity of about 280 mAh. Since you need two of these batteries in series that gives you 8.4 volts which is much higher than than the 7.2 volts that the probe expects from new single use 1/2AA batteries.
When I tried regular 1/2AA rechargeables in my probe it would not function and flashed a battery warning light sequence. The probe is very particular when it comes to its power requirements, even certain brands of single use 1/2 AA batteries are known to cause issues (see manual)
Also, even if you could get them to work there is the capacity issue, with a capacity of about 280 mAh 1/2AA rechargeable batteries would last about 2 weeks in your probe if you didn't use it and less if you did before needing to be recharged.

With a capacity of 5000 mAh the Renicharge will last just as long in your probe as single use 1/2 AA batteries and it outputs the correct voltages to imitate single use batteries in various stages of discharge so the probe responds correctly.
 








 
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