VAM/Caravel thermostats - anatomy and issues - Page 2
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Italyhound (original poster)
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Problem SOLVED.
I will not take the credit, as Francesco took one look at my pictures I sent him and told me the problem.
Take a look at the VAM kettle (top) and the caravel kettle (bottom).
There is a metal tongue that is attached to the VAM Kettle. On the Caravel, it is on the rocker assembly and held on by a phillips head screw. The latter piece is pictured in previous posts on this thread. It is this metal tongue is a major factor when the tstat will click off. If it is screwed in too tight and stiff, it will not be pushed back with the kettle in place and it will cause the element to shut off too quickly. If you loosen it, as I eventually did, it will allow movement to the back of the frame when the kettle is seated - and will let the machine boil away. It might be that those folks who changed to new springs and had success actually were forcing that tongue back further with the increased spring tension - that's a guess and perhaps another fix.
Anyway, assuming your rocker is already set by the bottom screw so that the on/off switch will click the element on when powered up, the tongue placement will help you get to boil if it isn't screwed down tight like mine was.
From there, you can FINE adjust the temp knob which basically protrudes into the tongue and changes the point at which is clicks off. I would think that if you cant get a low enough temp with the knob at minimum that you would tighten that tongue a teeny bit and retest. Conversely, if too low - loosen the tongue.
Now I will eventually adjust my VAM, which should be easier since it is one less moving part to adjust - but I don't want to get ahead of myself.
I can't speak to deadbands yet, and since I am a one shot at a time pony, I wont likely experiment anytime soon but this might be a factor in deadband adjustment too - how easily that tongue can move a little back and forth with cooling/heating of the kettle.
I still have the issue of the blazing hot frame (see below), and that may indeed be a spring issue. As has been noted elsewhere, I can see the glowing red element through the space between the kettle and the frame, so I suspect that is the issue. That's my next thing to deal with ....
but I am boiling, so Arancina is in business!
I will not take the credit, as Francesco took one look at my pictures I sent him and told me the problem.
Take a look at the VAM kettle (top) and the caravel kettle (bottom).
There is a metal tongue that is attached to the VAM Kettle. On the Caravel, it is on the rocker assembly and held on by a phillips head screw. The latter piece is pictured in previous posts on this thread. It is this metal tongue is a major factor when the tstat will click off. If it is screwed in too tight and stiff, it will not be pushed back with the kettle in place and it will cause the element to shut off too quickly. If you loosen it, as I eventually did, it will allow movement to the back of the frame when the kettle is seated - and will let the machine boil away. It might be that those folks who changed to new springs and had success actually were forcing that tongue back further with the increased spring tension - that's a guess and perhaps another fix.
Anyway, assuming your rocker is already set by the bottom screw so that the on/off switch will click the element on when powered up, the tongue placement will help you get to boil if it isn't screwed down tight like mine was.
From there, you can FINE adjust the temp knob which basically protrudes into the tongue and changes the point at which is clicks off. I would think that if you cant get a low enough temp with the knob at minimum that you would tighten that tongue a teeny bit and retest. Conversely, if too low - loosen the tongue.
Now I will eventually adjust my VAM, which should be easier since it is one less moving part to adjust - but I don't want to get ahead of myself.
I can't speak to deadbands yet, and since I am a one shot at a time pony, I wont likely experiment anytime soon but this might be a factor in deadband adjustment too - how easily that tongue can move a little back and forth with cooling/heating of the kettle.
I still have the issue of the blazing hot frame (see below), and that may indeed be a spring issue. As has been noted elsewhere, I can see the glowing red element through the space between the kettle and the frame, so I suspect that is the issue. That's my next thing to deal with ....
but I am boiling, so Arancina is in business!
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drgary
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Well done! Isn't it satisfying when you solve one of these puzzles?
Regarding the overheated frame of the machine, I wonder if that happens when the heating element isn't sufficiently touching the kettle so that the kettle can act as a heat sink?
To determine deadband simply insert a food thermometer in the kettle and see what the low and high temps are. The difference is your deadband.
Regarding the overheated frame of the machine, I wonder if that happens when the heating element isn't sufficiently touching the kettle so that the kettle can act as a heat sink?
To determine deadband simply insert a food thermometer in the kettle and see what the low and high temps are. The difference is your deadband.
Gary
LMWDP#308
What I WOULD do for a good cup of coffee!
LMWDP#308
What I WOULD do for a good cup of coffee!
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Italyhound (original poster)
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I think so too. That's why maybe worn out springs may be at play in not keeping the element and the kettle best apposed.
My point to the deadband was that maybe the tongue adjustment would be a key in tightening it, should that be an issue w folks who have a very wide one. Not sure. Easy for someone to try out.
My point to the deadband was that maybe the tongue adjustment would be a key in tightening it, should that be an issue w folks who have a very wide one. Not sure. Easy for someone to try out.
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Italyhound (original poster)
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I clearly need to work more, but having some days off of work is good for the Caravel world.
I have solved my hot frame issue with help again from that all important page 89 of The Arrarex Caravel thread, and again Jack comes through.
First off, the back of the element tray is mounted in the photo above. Mine was at the top of screw along the spring. That is wrong - the element will sit too low. It needs to be just under that philips head screw, beneath that notch - you may need to pull the spring/nut down a bit to get it in there. Now I see the function of the tensioning screw with the spring underneath it. To push the element up and keep it in place.
The two springs on the front of the element tray spring up to appose the base of the kettle to the element.
In my case, if you pressed the tray down, only the right side would pop up. That is because the hook on the back of the tray was not pushed back far enough; therefore, when the tray was pushed down by the kettle, it would spring up back up against it - it was stuck with poor clearance at the front. The element had a big gap.
I fixed it, confirmed the springiness, and it now gets hot but not blazing. My thermopen said 120F.
I hope that helps someone else - either now or in the future. You can definitely play with the tension on the front springs and not get into any trouble. You know you have made a big enough 'mistake' when the piece with the caravel logo doesn't fit onto the frame. It means the kettle is seated too low on the affected side.
Now, to break out the VAM and adjust the thermostat on that one. Will report back.
I have solved my hot frame issue with help again from that all important page 89 of The Arrarex Caravel thread, and again Jack comes through.
First off, the back of the element tray is mounted in the photo above. Mine was at the top of screw along the spring. That is wrong - the element will sit too low. It needs to be just under that philips head screw, beneath that notch - you may need to pull the spring/nut down a bit to get it in there. Now I see the function of the tensioning screw with the spring underneath it. To push the element up and keep it in place.
The two springs on the front of the element tray spring up to appose the base of the kettle to the element.
In my case, if you pressed the tray down, only the right side would pop up. That is because the hook on the back of the tray was not pushed back far enough; therefore, when the tray was pushed down by the kettle, it would spring up back up against it - it was stuck with poor clearance at the front. The element had a big gap.
I fixed it, confirmed the springiness, and it now gets hot but not blazing. My thermopen said 120F.
I hope that helps someone else - either now or in the future. You can definitely play with the tension on the front springs and not get into any trouble. You know you have made a big enough 'mistake' when the piece with the caravel logo doesn't fit onto the frame. It means the kettle is seated too low on the affected side.
Now, to break out the VAM and adjust the thermostat on that one. Will report back.
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dumpshot
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Regarding the front springs:
As I stated before, I replaced mine with some very unscientifically eyeballed springs from Ace Hardware quite a while ago. I bought them on a whim with the intention of just seeing what would happen and then replacing them with something more accurate in the future.
Well, it turned out that the springs were probably too long and too wide and too thick. HOWEVER, I don't think that too much tension is a bad thing in this case. I need to use some force to lock in the kettle. But when it clicks in, it REALLY clicks in. I know that I am getting maximum contact with the element and my t-stat works well with about a 9-10 degree deadband.
For anyone's reference or for further discussion, here are the sizes of the front springs I bought and the springs that Doug put on the OE VAM I have (or maybe they are OEM?):
Pete's super large Ace hardware springs: 22mm tall x 12mm diameter.
Doug's VAM springs: 17mm tall x 7mm diameter.
Another topic:
The body of my VAM is still unusually hot. Why, I don't know. At this point I am OK with it operationally, but would like to know why more heat is transferred to the body than other machines. I can tell you that this has been true through four elements, two sets of springs, and two paint jobs!
Anyone with more clues?
Pete
As I stated before, I replaced mine with some very unscientifically eyeballed springs from Ace Hardware quite a while ago. I bought them on a whim with the intention of just seeing what would happen and then replacing them with something more accurate in the future.
Well, it turned out that the springs were probably too long and too wide and too thick. HOWEVER, I don't think that too much tension is a bad thing in this case. I need to use some force to lock in the kettle. But when it clicks in, it REALLY clicks in. I know that I am getting maximum contact with the element and my t-stat works well with about a 9-10 degree deadband.
For anyone's reference or for further discussion, here are the sizes of the front springs I bought and the springs that Doug put on the OE VAM I have (or maybe they are OEM?):
Pete's super large Ace hardware springs: 22mm tall x 12mm diameter.
Doug's VAM springs: 17mm tall x 7mm diameter.
Another topic:
The body of my VAM is still unusually hot. Why, I don't know. At this point I am OK with it operationally, but would like to know why more heat is transferred to the body than other machines. I can tell you that this has been true through four elements, two sets of springs, and two paint jobs!
Anyone with more clues?
Pete
LMWDP #484
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Italyhound (original poster)
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Pete
Thanks a lot for the spring info. I was at lowes and got whatever they had - not very compressive. I am going to inspect my springs tomorrow in the VAM too.
I took apart my VAM 1.0 - which also doesn't boil at the moment but comes far closer than my caravel 2.0 did to start. Francesco told me the way to adjust this that is to move the tongue on the back of the VAM kettle closer to the body.
I believe this is different from what DrGary did when he bent the rocker bar (and does not advise doing that!) on his caravel 1.0.
There is no other adjustment potential on the VAM T-stat rocker other than the temp adjustment knob at the bottom. So I think you have to slightly move that tongue back as Francesco said. As I said previously, on the early kettle, the tongue is attached - as opposed to mounted on the rocker in later versions (which can be loosened and tilted back further).
As far as the body heating excessively: Are you seeing the element glowing at all around the kettle? Is one side of the frame clearly hotter than the other? I believe you said that you never played with the back spring although I could be wrong(?). That is involved in forcing the back of the element up against the kettle. You might want to remove the kettle, give a good press and see - and maybe change the tension on the back spring. This is not proven, but I don't think the kettle when seated is level - so if the tension front-back is off you may have a posterior gap, and a heat sink that is not helped by the front spring.
Thanks a lot for the spring info. I was at lowes and got whatever they had - not very compressive. I am going to inspect my springs tomorrow in the VAM too.
I took apart my VAM 1.0 - which also doesn't boil at the moment but comes far closer than my caravel 2.0 did to start. Francesco told me the way to adjust this that is to move the tongue on the back of the VAM kettle closer to the body.
I believe this is different from what DrGary did when he bent the rocker bar (and does not advise doing that!) on his caravel 1.0.
There is no other adjustment potential on the VAM T-stat rocker other than the temp adjustment knob at the bottom. So I think you have to slightly move that tongue back as Francesco said. As I said previously, on the early kettle, the tongue is attached - as opposed to mounted on the rocker in later versions (which can be loosened and tilted back further).
As far as the body heating excessively: Are you seeing the element glowing at all around the kettle? Is one side of the frame clearly hotter than the other? I believe you said that you never played with the back spring although I could be wrong(?). That is involved in forcing the back of the element up against the kettle. You might want to remove the kettle, give a good press and see - and maybe change the tension on the back spring. This is not proven, but I don't think the kettle when seated is level - so if the tension front-back is off you may have a posterior gap, and a heat sink that is not helped by the front spring.
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redpig
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This is exactly how I adjusted my VAM. I bent the bar ever so slightly away from the kettle toward the body. It doesn't take much either! (I had to undo overzealous bending...)Italyhound wrote:You have to slightly move that tongue back as Francesco said. As I said previously, on the early kettle, the tongue is attached - as opposed to mounted on the rocker in later versions (which can be loosened and tilted back further).
The springs in my VAM are still pretty springy, but I always thought they were for ensuring good element contact, not temp adjustment, but I'll investigate again.
LMWDP #411
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redpig
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I am still using the original 160v element in my VAM (until my cafelat package arrives) and the frame gets pretty warm for me. I just assumed it was the reality of a hot element, a closed space, and lots of metal. I'd love to find out if I could keep it cooler, but I've never worried about it. Maybe I should be?dumpshot wrote:The body of my VAM is still unusually hot. Why, I don't know. At this point I am OK with it operationally, but would like to know why more heat is transferred to the body than other machines. I can tell you that this has been true through four elements, two sets of springs, and two paint jobs!
Anyone with more clues?
LMWDP #411
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dumpshot
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Hmmmmm... curious. This theory makes total sense. I will investigate and report back. Thanks a lot, Evan.Italyhound wrote: As far as the body heating excessively: Are you seeing the element glowing at all around the kettle? Is one side of the frame clearly hotter than the other? I believe you said that you never played with the back spring although I could be wrong(?). That is involved in forcing the back of the element up against the kettle. You might want to remove the kettle, give a good press and see - and maybe change the tension on the back spring. This is not proven, but I don't think the kettle when seated is level - so if the tension front-back is off you may have a posterior gap, and a heat sink that is not helped by the front spring.
Pete
LMWDP #484
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Italyhound (original poster)
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As I am now working on the temp control on my VAM. This is the opposite of the Caravel - which clicks the element on when the top of the rocker is moved back. So in the VAM, the top has to stay forward to keep the heat on.
I can't help but wonder if the Caravel tstat adjust is an improvement that they made over the VAM, I know that is heresy but it seems more flexible on the Caravel. On the VAM, the metal tongue on the kettle has to be bent (so far that has proven a p.i.t.a. because I overshot it to the point where it wouldnt kick on at all). On the caravel, you can manipulate it easily with a turn of the screw.
I think the other area on the VAM where the adjustment is made is with the two front springs in the little balls. This has been described, but I think it is more important on the VAM, as the tension on those front springs changes the slope of the kettle. The more it can tilt forward, the more the element will stay on.
I had the element kicking off at 170F, and when it cooled I played with the tensioning of the front springs. No change. I will play more, with these and perhaps the back spring too since I know the direction I want to kettle to settle in.
more to come....
I can't help but wonder if the Caravel tstat adjust is an improvement that they made over the VAM, I know that is heresy but it seems more flexible on the Caravel.
On the VAM, the metal tongue on the kettle has to be bent (so far that has proven a p.i.t.a. because I overshot it to the point where it wouldnt kick on at all). On the caravel, you can manipulate it easily with a turn of the screw.I think the other area on the VAM where the adjustment is made is with the two front springs in the little balls. This has been described, but I think it is more important on the VAM, as the tension on those front springs changes the slope of the kettle. The more it can tilt forward, the more the element will stay on.
I had the element kicking off at 170F, and when it cooled I played with the tensioning of the front springs. No change. I will play more, with these and perhaps the back spring too since I know the direction I want to kettle to settle in.
more to come....
