Fix a spring steel thermostat on Caravel?

#1: Post by **peacecup** » November 23rd, 2014, 9:20 am

The thermostat on the Caravel turns off the heating element by the expansion of a spring steel strip when the boiler gets hot. On my boiler the steel spring is bent too far outwards, and it expands too far before the boiler quite reaches the boiling point.

I need to figure out a way to bend this steel strip back inwards a bit. I tried rolling it with a rolling pin and it worked a little, but not enough. A simple problem, but no simple solution that I can think of. Any ideas?

#2: Post by **drgary** » November 23rd, 2014, 12:53 pm

Jack:

Don't bend it. You have a VAM, I believe. The tensioning of the kettle against the thermostat rocker switch is adjusted by springs inside tiny adjustment knobs under the front of the group that raise or lower the front part of the heating element and an adjustment screw inside that tensions the back of the heating element carriage and tensions that entire assembly. This has been discussed under postings about the SEPS system. I tackled this on my Carvavel 1.0, bent that tab and regretted it. I bent it back as best I could (now it works fine) and adjusted the SEPS system.

November 24th, 2014, 2:39 pm

I did bend it out a little, which was a mistake. I think I have those front adjustment screws all the way out, so I can't tilt the kettle any further away from the themostat switch.

Anyone have any idea how I can bend that clip inwards a little. I rolled it with a rolling pin and that had some effect, but I wondered if anyone has a better idea?

PC

#4: Post by **drgary** » November 26th, 2014, 3:12 pm

I did that with thin needle nosed pliers that I used to grip mostly near where it attaches. This gave me a curve rather than the original flat tab, but it adjusted it back into range where it touches the rocker for the microswitch.

#5: Post by **cuppajoe** » November 27th, 2014, 12:59 pm

Hi Jack -

For situations like this I use a precision screwdriver with a thin shaft. Force the shaft between the spring and what it is fixed to and get it down as far to the attachment point as possible. This gives you a fulcrum point to bend the spring inward. Any thin rod-like material will work.

Hopefully you can make sense of that.

November 27th, 2014, 3:52 pm

Yes I understand that - a very good idea. The same principle that Gary suggested but slightly less invasive. I'm going to try it before I go to bed!
PC

November 27th, 2014, 4:25 pm

I love the HB community.

I found a paper clip, thinking that a round fulcrum would work nicely. I wedged it down as far as it would go and tried the rolling pin method again. This time Bob was definitely my uncle, and the top end bent in exactly as would be expected. I'm testing it now and will have a chance to pull shots over the weekend.

This VAM version has a 2-stage themostat switch. The outer knob is used for coarse adjustment, and the inner knob for fine-tuning within the basic temperature range. Incredible design.

PC

November 27th, 2014, 4:48 pm

I got mine really hot by boiling the water for a few minutes. Carefully removed and emptied the hot water, then push and rubbed (sounds bad) the metal tab with the plastic side of a 2 sided rubber / plastic mallet. Repeated several times until it was as flat as it was going to get,

Then very gently made many tiny adjustments outward again over time with the tip of a flat head screw driver (when hot / just been used) to get the tab in balance with the SEPS. My 1.0 thermostat is now quite useful / adjustable.

#9: Post by **drgary** » November 27th, 2014, 5:12 pm

peacecup wrote:This VAM version has a 2-stage themostat switch. The outer knob is used for coarse adjustment, and the inner knob for fine-tuning within the basic temperature range. Incredible design.

Can you please show us a photo of that thermostat switch? I checked Francesco Ceccarelli's VAM photos and don't see it there. You may remember that awhile back we discovered some machines with On/Off switches and those hadn't been documented previously.

Aren't you glad you kept it?

November 27th, 2014, 5:19 pm

Dr Jim was one of our early inspirators here on the lever forum. It was when I recalled him writing that he sold an Olympia Club in a moment of temporary insanity that I decided I'd probably never own another VAM 1 if I sold this one. Now I have new top-notch seals from Kurt and a functioning thermostat and I'm ready to get down to business.

Next I need to address a re-wiring job and a cracked element insulation block.