iSpindel Digital Hydrometer

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Okay, Moad I found your post with your sled on dropbox (red)

Below is a comparison of the size of this versus DRAWER-COMBO-SHORT-SPRING2_STL (blue)

The one a lot of users had printed by Kerry from 3D hubs is significantly bigger.

What bottle did you guys find to work with this?

View attachment 109498
I used the sled from post #1, the tinkercad one I think it is. This fits loose in the XXL bottle from eBay. I added a little bit of padding on each side and it sits nice and snug
 
Got my iSpindel working. I'm running through a fast ferment for calibration right now.

I ended up needing 30g of weight to make sure the iSpindel was at a good angle in tap water (my angle there was 23.32°).

I'm seeking a bit of advice from anyone who has set one up already.

My calibration angle in tap water was 23.32°

I made up a 1.084 SG sugar solution and pitched yeast into that. Initially the iSpindel angle was ~58°. All good at that stage.
I pitched some SO4 and noticed fermentation activity, krausen etc. 24 hours after first pitching yeast I notice that the angle has actually increased by ~5° to be ~63°. It's only gone back down a few degrees since then. So how on earth do I take this rise in angle into account for calibrating? A bit hard to get it accurate with a 5° discrepancy for the starting gravity of 1.084.
 
I don’t think they are very accurate for various reasons. I’ve seen this as well and I don’t know why.

I won’t be using mine to change temps as it is not accurate but it does give you a decent idea of where the ferment is up to based on the graph. You’ll at least know when your ferment is done and be able to take one sample to take FG rather than a few along the way
 
I have only done one brew with mine but I found the readings to be very stable.

This is my tilt angle curve (I haven't calibrated it properly yet so just no SG on this) , the biggest blips were less than 1% apart from the cold crash. Of note are the hydrometer readings (taken from the tap at the bottom of my plastic fermentation vessel), both of them caused a drop in angle (possibly from pressure drop in the fermenter after taking a 100ml sample?). Also the dry hop addition caused an increase in angle (I think I bumped the iSpindle)
upload_2017-11-7_12-32-18.png
 
I have only done one brew with mine but I found the readings to be very stable.

This is my tilt angle curve (I haven't calibrated it properly yet so just no SG on this) , the biggest blips were less than 1% apart from the cold crash. Of note are the hydrometer readings (taken from the tap at the bottom of my plastic fermentation vessel), both of them caused a drop in angle (possibly from pressure drop in the fermenter after taking a 100ml sample?). Also the dry hop addition caused an increase in angle (I think I bumped the iSpindle)
View attachment 109546
Dry hopping introduces fermentables in the form of glucose and enzymes contained in the hops. I recent talk from Yakima Farms at home brew con talked about this.
 
Dry hopping introduces fermentables in the form of glucose and enzymes contained in the hops. I recent talk from Yakima Farms at home brew con talked about this.

That is interesting. Does that mean I should be leaving it longer to ferment before cold crashing after dry hopping. I always assumed that hop oils were unfermentable and usually cold crash and fine one day after adding them so I get a total of 3/4 days dry hopped before kegging.
 
I got round to building an iSpindle last weekend (after having parts dribble in for what seemed like forever). I have gone the wireless charging route too, and am using the following product:
https://www.aliexpress.com/item/Wireless-Charger-Receiver-Module/32279028531.html

It gets a little warmer than I would like and doesn't have two way communication smarts to turn itself off (like the cell phone ones do) but charges the battery successfully. I just turn it off when the battery lipo charger board lights up blue.

The receiver coil fits inside the inner lip of the lid of the PET bottle so the bottle can sit upside-down on its lid and charge.

I aim to never open my bottle once it is calibrated so I picked up a couple of magnetic reed switches (https://www.jaycar.com.au/glass-reed-switch-n-o/p/SM1002) from Jaycar.
One to replace the toy switch (to turn off the device when sitting in my charging station), and one to replace the Wemos reset switch so i can double tap the switch to enter config mode.

Hi, some options to consider:

  • Replace you reed switch with a Capacitive Touch sensor (TTP223B). This works through some surfaces. It can be connected to the RST to reset the Wemos, or as a general purpose switch. So device is 100% sealed, but with touch sensistive switches :)
  • If you never want to open it again I suggest you put the Wemos into "deep sleep" mode. In this mode is uses virtually no battery. Depending on your battery quality, could last for years. The Wemos can be scheduled to wake every hour or so and grab a sample. This reduces battery consumption enormously, and no need to worry about LEDs, as they will be mostly off.
Small TTP223B: https://www.aliexpress.com/item/10P...lgo_pvid=85d13aeb-a47d-4473-bb27-1c7a148f045a
 
Hi everyone. Sorry I just did a recount of the boards i bought. I ended up getting 25 @ $48.48 So works out around $2 per board. I have some with spares from Aliexpress. Would have been good if I counted the boards before I posted on the forum. Anyway pm me if intrested. The extra spares will be $1extra. This includes the micro switch, the diode, the usb charging port and the two resistors.
Just let people know. I have none of the spares left. The boards I still have and will post out with the resistors. $2 each board and $1 for postage.
 
The link to the stli on post 1 does not work. I ran a few of the stl files through the quote mechanism on 3D Hubs and they all error for PLA with some walls too thin for FDM printing.
Anyone know where you can buy a kit of parts? Might be just as cheap when multiple shipping charges are factored in (I'm in Canada btw).
 
The link to the stli on post 1 does not work. I ran a few of the stl files through the quote mechanism on 3D Hubs and they all error for PLA with some walls too thin for FDM printing.
Anyone know where you can buy a kit of parts? Might be just as cheap when multiple shipping charges are factored in (I'm in Canada btw).

Hi Dwayne, have a happy new year.
Maybe you may want to take a look at this eshop (https://www.3d-mechatronics.de/en/ispindel-diy-set_151.html).
That is where I got my kit from. Everything needed is supplied except a 20 gram counterweight that might also be needed.
 
Thanks for the link and happy new year.
What do those of you who sourced the parts yourself reckon you ended up paying for the finished ispindle ? Just wondering what the saving would be over buying the kit in the above link.
I'm planning on getting 2 or 3. Which would cost $120-180 CAD +shipping and possibly duty.
 
Thanks for the link and happy new year.
What do those of you who sourced the parts yourself reckon you ended up paying for the finished ispindle ? Just wondering what the saving would be over buying the kit in the above link.
I'm planning on getting 2 or 3. Which would cost $120-180 CAD +shipping and possibly duty.

My costs are not the cheapest possible. Diodes, resisters and battery were from local shops (ie 200% markup) and wireless charger was local stock off ebay (50% markup). Rest was from ebay/aliexpress and all includes shipping. AUD but not far from CAD

Code:
Temp Probe        1.85
PET Bottle        3.87
Gyro              1.35
Sled              5.63 (13.03 + 9.50 shipping for 4 sleds)
LiPo Charger      0.53
LiPo Battery      8.90
Wemos D1 Mini     3.99
Resistors         0.96
Diode             1.50 (replaced reset resistor)
Switch            1.95 (tilt - replaced toy switch)
PCB               1.49 (7.45 for 5)
                 =====
                 32.02

Optional:
Switch            2.75 (magnetic reed - replace Wemos reset)
Wireless Charger  7.99
                 =====
                 42.76
 
Just let people know. I have none of the spares left. The boards I still have and will post out with the resistors. $2 each board and $1 for postage.
Hi Everyone,
I have sold out of the boards.
Still yet to build the ones I bought. Hope I have helped some people out to get started.
Cheers
Chucka
 
Was keen to make a glass version of this. Anyone endeavoured to source a suitably sized glass test tube or similar?
 
Was keen to make a glass version of this. Anyone endeavoured to source a suitably sized glass test tube or similar?
Just my 2 cents (and maybe I'm wrong)
I was thinking about this and still not sure if it's a good idea. Glass is much heavier than the plastic tube so the rate of angle variation / gravity will be smaller than in the plastic one.

As a conclusion you will have a device that can measure gravities over 1.100 but will lose a lot in terms of resolution.
 
Hi guys, just build my ispindel and ran it through 2 calibration tests. It seems to be working fine but after each calibration, i test it again in plain water and keep getting a sg reading of 1.003 both times.
Cant seem to get it to 1.000. I did make a variable in ubidots though that subtracts the extra .003 but dont know if i should be doing that.

Does anybody know how to make a variable in ubidots that can show ABV value as fermentation progresses ?
Or anyway of grabbing only the initial reading of OG ?

Thanks
 
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