iSpindel - digital WiFi hydrometer

[Harry Bloomfield]

Ballast help needed
Just finished building using a 4.0 pcb.
All working ok but I can't get anywhere near 25 degrees in plain water, not much spare space for weights in the current tube, shouldn't go for more weight in the larger tube?
Any tips gratefully received, thanks

This was my reply to someone with the same problem, in another forum...

Same pcb here, in a PET big XL. I assume you have done the 90 deg calibration, with the PET perfectly horizontal?

I soldered my battery in, rather than use a holder and proceeded to try to get it to 25 deg. It floated only slightly down from horizontal at the bottom. To get an idea of the amount of extra weight needed to get it to 25 deg., I wrapped 4mm plumbers lead around the outside of the PET at the bottom. It seemed I needed around 20g or 2 x 2" lengths. I moved the battery down as far as possible, then stuck a strip of that spongy double sided tape to the pcb, either side of the battery, then the lead onto that. That had it floating at 16 deg and I was able to snip off lead from the upper ends, 4mm at a time, until I hit 24 deg at 20C. I think my final weighting was 16g of lead.

I see you said a larger PET. The larger the PET, the greater the displacement, the more the weight needed to get the correct 25 deg.. The lower you can get the weight in the PET, the less weight will be needed.

 

[gingerneil]

Ballast help needed
Just finished building using a 4.0 pcb.
All working ok but I can't get anywhere near 25 degrees in plain water, not much spare space for weights in the current tube, shouldn't go for more weight in the larger tube?
Any tips gratefully received, thanks

I found that a lump of sugru in the bottom with a couple of buttons stuck in it worked well for me. Does mean everything is stuck in the tube tho, but at least its all stable and fixed in place.

 

[Adean]

Which size tube are you using, and is the board snug in there?

Have you done the sensor calibration in the maintenance page (not the full iSpindel calibration, this one just makes sure it reads flat as flat)

What angle are you getting? Have you got a picture?

Photos as requested - I have also had the battery on the scales, only 29g - please don't be too harsh with comments on my soldering skills ! ;-)
I'm sure it's something blatantly obvious but I just can't work it out
Screenshot while flat on table after calibration plus screenshot as per floating image.
Many thanks in advance
Alastair

 

[gingerneil]

That battery is definitely suspect.. they should be around 45g I think. I need to order some, and its very tempting to buy cheap ones - but you can almost guarantee they'll be fake and/or dangerous! You need to be paying about £4-£5 a battery.

 

[Adean]

That battery is definitely suspect.. they should be around 45g I think. I need to order some, and its very tempting to buy cheap ones - but you can almost guarantee they'll be fake and/or dangerous! You need to be paying about £4-£5 a battery.

Thanks. I'm going to try and get a Samsung one instead

 

[pottsworth]

Unfortunately both of my batteries are currently in batches of beer, but google suggests they should be about 45g.

You also have the older V1/V2 Wenos which may we’ll be a few grams heavier.
try sticking 20g of ballast in the bottom and see if that helps.

Alternately it might be worth trying a different battery, as I’d assume less weight = less lithium = less able to sustain charge.

 

[Adean]

Unfortunately both of my batteries are currently in batches of beer, but google suggests they should be about 45g.

You also have the older V1/V2 Wenos which may we’ll be a few grams heavier.
try sticking 20g of ballast in the bottom and see if that helps.

Alternately it might be worth trying a different battery, as I’d assume less weight = less lithium = less able to sustain charge.

Thanks. I'm going to source a different battery and see if I can squeeze some ballast in the tube as well.
Thanks for your help

 

[CBBC]

I have 3 v4.0's left with more on the way
I've managed to source everything but still waiting on a few things to actually arrive, they will be on ebay either tonight or tomorrow

Hi Wezzel any joy getting them on eBay yet?

 

[Adean]

Unfortunately both of my batteries are currently in batches of beer, but google suggests they should be about 45g.

You also have the older V1/V2 Wenos which may we’ll be a few grams heavier.
try sticking 20g of ballast in the bottom and see if that helps.

Alternately it might be worth trying a different battery, as I’d assume less weight = less lithium = less able to sustain charge.

Just ordered a replacement battery listed as 47g so that should help.
I'll report back when installed and tested.
Thanks
Alastair

 

[gingerneil]

Hi Wezzel any joy getting them on eBay yet?

I'm in the process of building some to pop on ebay too - so shout or keep an eye out there in the next week or so if you want one.

 

[Adean]

I'm in the process of building some to pop on ebay too - so shout or keep an eye out there in the next week or so if you want one.

I'm thinking of building a 2nd one if you'll excuse me jumping on this thread!

 

[private4587]

Does anyone have an up today parts list for these, i have the older on that used a sledge. But i gather the more modern way is to used a PCB. Would be very grateful as i want to progress with this project. I do have a lot of the smaller parts for the original design.

 

[pottsworth]

Does anyone have an up today parts list for these, i have the older on that used a sledge. But i gather the more modern way is to used a PCB. Would be very grateful as i want to progress with this project. I do have a lot of the smaller parts for the original design.

There is a full parts list here, and they make a PCB. The same parts list will also work with the cherry Philips iSpindel 4.0 board from PCB way

https://www.opensourcedistilling.com/ispindel/

 

[ChrisT]

@private4587 The first iSpindle I build was the sled and I built that on a piece of veroboard, I later upgraded this to the PCB. I later got hold of a CherryPhilip V4 PCB and then some OpenSourceDistilling V2 PCBs.

The parts I used are the same across each of these 3 variants, except for the switch. However, the switch is the same on the CherryPhilip and OSD PCBs.

In my personal opinion the OSD PCB is the better one, because of the "wings" added to the PCB to make it easier to tailor the fit to your Pelting. I found the assembly of the CherryPhilip and OSD PCB essentially the same process, each PCBs is marked well enough to locate and orientate each component, but look at the assembly videos for each, it does help with the easiest sequence.

I've got some stuff left over which I'll be listing in the for sale this evening if your interested.

 

[ChrisT]

I should also add, buy a real 18560 battery, look for one that is listed as more than 40g in weight. If the weight isn't given, move on to the next listing.

My first batteries were cheap knock offs and they gave a reasonable battery life but were VERY light, required an M10 nut added. The last iSpindle I built with a real battery didn't need any additional weights.

 

[Adean]

I should also add, buy a real 18560 battery, look for one that is listed as more than 40g in weight. If the weight isn't given, move on to the next listing.

My first batteries were cheap knock offs and they gave a reasonable battery life but were VERY light, required an M10 nut added. The last iSpindle I built with a real battery didn't need any additional weights.

I had the same problem. First battery was a copy and only weighed 29g was a nightmare to get the angle lower than 70 degrees. Replacement ordered and quoted at 47g, just waiting for it to arrive.

 

[Wezzle]

I'd also recommend not skimping on the batteries, not to say fakes are dangerous, but the capacities are massively inflated. I have a "3600mah" Ultrafire which is actually around 800mah. It's been relegated to a torch by my electric meter.
I would say - go for a genuine PROTECTED cell. the small protection circuit adds to the weight and is a backup should the charge board fail, soldered something wrong, or you use the 4-pin TP4056

Hi Wezzel any joy getting them on eBay yet?

i'll be adding them around 8pm tonight

 

[Harry Bloomfield]

Another quick update on my iSpindel progress, plus a question....

Proper switch fitted in place of my pins + jumper and a new 3400mA (49g) battery fitted, to replace my original used 2200mA (40g) battery. This latter was showing signs during a couple of test runs, of it not being able to last through a fermentation. Strangely, its capacity seemed to be improving with each test run and recharge.

New battery took 5 hours to fully charge, before the blue LED came on. With the heavier battery, on my V4 pcb and in a big XL PET, calibrating the the 25 degrees needed much less lead at the base. Total of lead needed was around 4g, this I stuck with double sided tape, in two equal amounts, one either side of the battery. This so as to get the pcb to float horizontally.

The pcb has some free movement inside the PET, but it always seems to settle in the same spot in the PET. Opening up/ recharging doesn't seem to make much difference to the reported tilt, when compared to its natural errors.

I then moved onto the tricky job of trying to sort out the polynomial expression. I used the online web calculator, which could be set to produce an SG result - iSpindel Calibration. Rather than work down from highest to lowest density, it seemed more sensible to begin with pure water at 20C, then add and dissolve sugar step by step to calibrate against my hydrometer. Trying to use my hydrometer, was a miserable failure, because it was so difficult to read sat in my 5L bucket. Instead I swapped to using my refractometer, which allowed me to gradually add sugar, dissolve, then take SG and record tilt eight values, every 0.010, from 1.000 up to 1.080, which I then fed into the calculator.

Question - The calculator produced three output values :-

Degree 1:y = 0.002136398x + 0.947774285

Degree 2:y = 0.000015813x^2 + 0.00080716x + 0.973129924

Degree 3:y = 0.000001691x^3 + -0.00019427x^2 + 0.009101072x + 0.86958553

I tried editing/pasting the Degree 2 values in the iSpindle's line for the equation, but there didn't seem to be enough space in the line, ignoring that and saving it anyway, then checking it in tap water with Ubidots - the SG values were gibberish.

I then resorted to pasting in the Degree 1 value like this '0.002136398*tilt+0.947774285', which it seemed to accept. Is space for the equation limited?

I then moved onto to starting a 5gallon batch of red wine, using the iSpindle in earnest - rather than waste my already dissolved in water sugar. My initial mix always works out with hydrometer or refractometer at an SG of 1.080. The ispindel/Ubidots is reporting a drifting value of 1.0807 at midnight, 1.0856 this morning, with a temperature variation of 18.813C to 19.375C over the same period. This seems to be pretty fair and reasonably stable output.

 

[pottsworth]

My equation (in Plato for brewfather) is:
-0.000005343*tilt^3 + 0.005028252*tilt^2 + 0.000356375*tilt + -6.13780388

My brewpi accepts a much longer equation (brewpi just reads angle and does the calculation itself), but 4 significant figures seems like plenty.

I’d expect the degree 1 to be fairly inaccurate, at least in the middle, as it’s a linear approximation of non linear behaviour. That said it should at least give a reasonable indication of the speed that the fermentation is going, and when it is stable, which for me is one of the most useful things.

 

[gingerneil]

I'm using the 2 degree equation in my ispindel with ubidots. Don't forget you can also derive the SG in ubidots itself rather than in the ispindel config.