La Pavoni early heating elements - a lesson on volume - Page 2

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bluesman
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#11: Post by bluesman »

redbone wrote:I was thinking of having the flange made
Have you considered 3D printing?

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redbone (original poster)
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#12: Post by redbone (original poster) replying to bluesman »

Currently 3D metal printing is outrageously expensive. I would not trust a plastic piece under load or heat.
Between order and chaos there is espresso.
Semper discens.


Rob
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drgary
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#13: Post by drgary »

redbone wrote: I was thinking of having the flange made and element bolt on base with dual elements. Sort of combining the old and newer SS element.
Issue is that I would have to have both a newer element and 1.25mm flange so it could be reversed engineered.
This might be a good track to explore. You'll almost always get a machine with a flange, even if the element is fried. What about drilling the existing flange and mounting a plate that could accommodate screws for a screw-on but retro element? It could be a rebuild kit, DIY, like voodoodaddy used to offer for 1st gen Pharos grinders. For those without tinkering confidence he would install the parts for a fee.

BTW my one experience getting a replacement element from Gabor in Hungary took maybe 2 - 3 weeks. He had a rebuilt element in stock but requires one in trade. So the moment he received my cooked element he shipped the replacement. It's an excellent rebuild and still works.
Gary
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bluesman
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#14: Post by bluesman »

redbone wrote:Currently 3D metal printing is outrageously expensive. I would not trust a plastic piece under load or heat.
Some key patents on 3d metal printing expired in 2016, and industry has taken advantage of this - the cost is plummeting. DMLS is already available for small metal parts at much lower prices than was the case in 2016, and continuous carbon fiber for 3D printing makes a very strong piece. There are several brand new desktop printers coming out in 2017 that will make small metal parts at very reasonable cost. We need to follow this carefully, as it'll revolutionize DIY.

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redbone (original poster)
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#15: Post by redbone (original poster) »

I was able to have a 3D printable STL file made based on the AutoCad DWG file.
The file may not transfer over well.
I've decided to do an inexpensive material 3D print model made for fitting purposes prior.
Also having some local CNC and foundry quotes. Should have costing by end of next week.

Between order and chaos there is espresso.
Semper discens.


Rob
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forbeskm
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#16: Post by forbeskm »

I have some brass to machine some conversion flanges here on a cnc I have access to. That brass is not cheap! Stefano's pricing is pretty good for the flanges. Keep us posted with what you come up with.

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redbone (original poster)
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#17: Post by redbone (original poster) »

I received some pricing regarding short length cartridge heaters vs spiral coil heaters (oem style).
The cartridge immersion heaters meet the requirements but I can't find decent pricing from any local distributors.
These are the one's I looked at.

* A cartridge heater is a tube-shaped, heavy-duty, industrial Joule heating element used in the process heating industry.
* NPT national pipe thread standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings.

J1J59-11757
WATLOW FIREROD HEATER
1/2" dia. X 1.5" long insertion length
120V, 200W
3/8" NPT single SS fitting, located 1.5" from disk end
12" teflon leads & seal

J3A51-11754
WATLOW FIREROD HEATER
1/2" dia. X 3" long insertion length
120V, 600W
3/8" NPT single SS fitting, located 3" from disk end
12" teflon leads & seal

or

J3A137-11754
WATLOW FIREROD HEATER
1/2" dia. X 3" long insertion length
120V, 750W
3/8" NPT single SS fitting, located 3" from disk end
12" teflon leads & seal

Depending on wiring and switch setup. The switch on low position would be setup to turn on the 200W element.
The high position switch would be setup to either run bot 200w & 600W simultaneously or the 750w on it's own.

Between order and chaos there is espresso.
Semper discens.


Rob
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bill
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#18: Post by bill »

Ah, you're thinking outside the box. I like it! My first thought is, do any current espresso machine manufacturers use cartridge heaters, and if not, why not. Maybe the cost vs. coil heaters? Also, are they susceptible to burnout if not in water? Any thoughts?
Bill
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redbone (original poster)
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#19: Post by redbone (original poster) replying to bill »

Cartridge heaters a fairly new technology vs classic tubular immersion heaters. Typically cartridge heaters cost more per unit but since they are straight in shape they are easier to install not requiring an expensive jig and labour in order to bend to specified shape.

I was recommended a cartridge heater by a thermal engineering company that buys product from a company that I work with. All immersion heaters are susceptible to burnout if run dry. There are more expensive variants with built in thermal cutoffs.

The cartridge heaters that were suggested took into consideration the height of the previous spiral coil as not to be above the set height and minimum water level as shown in the sight glass.
Between order and chaos there is espresso.
Semper discens.


Rob
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redbone (original poster)
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#20: Post by redbone (original poster) »

I was asked by one of the CNC shops quoting on the base if Aluminum could be used as it would be less expensive in material costs and cheaper to machine than Stainless steel.

Not a metallurgist but have concerns.

1) Can aluminum handle the thermal expansion.
2) Initially concerned about aluminum and health but understand that the boiler is brass and aluminum amount here is minimal and low chance of leaching in a non acidic environment. Water only, not cooking tomatoes or similar acidic.
3) Any issue with brass and aluminum within the same environment.
Between order and chaos there is espresso.
Semper discens.


Rob
LMWDP #549