timo888 wrote:http://en.wikipedia.org/wiki/Delrin

EDIT: I don't know Delrin's hardness relative to brass. It could be harder. But if it is softer than brass, a sacrificial bushing might be used to prevent or reduce deformation of the slot. If it is harder, perhaps a thin slot liner could be made from it?

EDIT: Delrin's hardness.

Hi Tim,
I would not suggest a soft thin material for a shim. Any small contaminants may get lodged into it and become abrasive in the extreme. A very hard material or at any rate a bit harder than the sliding part is good. It should be firm and properly shaped so as not to cause undue wear into one portion of the machine's anatomy.There are exceptions to this rule but the materials are unobtainium in cost and are made for machine tool rebuilding. Think $100 up!^^^
The piston rod itself might be plated with Magnaplate® or the group head wear area also. Even the inside of the cylinder / group.Only one wear surface. It is a Teflon® impregnated wear material that is plated onto/into the substrate and there are food safe versions I have used for specialized medical equipment. It is similar to the hardcoat plating inside the real high buck professional French cookware. It protects aluminum or other surfaces from darn near anything.
sincerely
richard
PS. I been away from this site too long! Missed all this last page. Great work Greg they are really nice! Nice straight-lining on the front plates!

Not much dialog on this post........- I just got my box I have been waiting for.!!!!!!

Three new items for the 85

More about the specifics on who made them, what etc and some process pictures of their making on another day. Suffice to say that with these - I completed the machines except for the body panels and a few screws and tweaks here and there. They got water today, switched on, NO shorted circuits--YEAYYYYYY!

They warmed up, pressurized, flushed the groups and I turned them off.

So this side by side shot is a little like a before "Baubles" and after "Baubles" -African Ebony in a form I have had drawn on my wall for about a year- This style is what was on the first picture I ever remember seeing when I did a Google search for LEVER ESPRESSO..... a little over a year ago. ...... I like old school.... And I always liked the boiler cap.....







G' Nite

espressme wrote:Hi Tim,
I would not suggest a soft thin material for a shim. Any small contaminants may get lodged into it and become abrasive in the extreme. A very hard material or at any rate a bit harder than the sliding part is good. It should be firm and properly shaped so as not to cause undue wear into one portion of the machine's anatomy.There are exceptions to this rule but the materials are unobtainium in cost and are made for machine tool rebuilding. Think $100 up!^^^

The piston rod itself might be plated with Magnaplate® or the group head wear area also. Even the inside of the cylinder / group.Only one wear surface. It is a Teflon® impregnated wear material that is plated onto/into the substrate and there are food safe versions I have used for specialized medical equipment. It is similar to the hardcoat plating inside the real high buck professional French cookware. It protects aluminum or other surfaces from darn near anything.

Hi Richard,
The specific wear-issue I was trying to solve is the deformation of the slot in the fulcrum mount and the wearing thin or even the wearing-through of the brass at that location. The abrasion there is much exacerbated by the thousands of pounds of force applied to the hardened steel pin and then to the brass, via the lever. If Delrin is harder than brass (I think it is), it might make a decent slot liner. I don't know how thin it can get before it looses its strength. Perhaps something like this, but less ovoid and more lozenge-shaped:



Teflon-coating of the piston cylinder is something I would consider; you know the EPA's take on brass in potable water systems.... I have been reading about electroless nickel-teflon coatings, but will look for Magnaplate.

BTW, the company that originally said it would take on the job of replating my boiler has gone incommunicado. Can you recommend another who might have experience with Magnaplate?

Regards
Timo

Hi Tim,
posted the answer on Vintage boiler's thread.
edit:
http://www.home-barista.com/levers/vintage-boilers-metals-t4065.html#44544
Enjoy,
richard

timo888 wrote:... If Delrin is harder than brass (I think it is), it might make a decent slot liner. ......
Regards
Timo

I think the roller made out of Delrin would be the thing to try- should be easier to make and would be - even though harder= possibly less abrasive? Or am I out in the far pasture eating Loco -weed?

mogogear wrote:I think the roller made out of Delrin would be the thing to try- should be easier to make and would be - even though harder= possibly less abrasive? Or am I out in the far pasture eating Loco -weed?

Delrin is an offshoot of Nylon®6, (a white somewhat oily feeling material that is slightly flexible.) It is not as hard as cycolac or plexiglas. It gets its value from the slight flexibility, shock resistance, and slipperiness. It does not absorb any water as Nylon® can. It is often used in bearings for consumer home mixers and such and as the bushings for electric knives.
As an example, the Delrin® pin could be cut with a hand held dykes ( diagonal cutter.) It does shear easily. Meaning it would leave the two ends in the fork and the middle in the group with a half hearted drop of the lever. There are plastics we have used that would do the job thing ^^$200 per ounce.
enjoy!
richard
hey, lets move this somewhere else so the twins can be center stage!?!?

espressme wrote:hey, lets move this somewhere else so the twins can be center stage!?!?

Richard,
They have center stage, whether this ancillary subject of how to protect the slot from wear stays or goes. The reason we are talking about how to retrofit the slot is that Greg went to extraordinary lengths to repair the problem of a slot deformed by years of use, as his photographs early in the thread attest.

Regards
Timo

timo888 wrote:Richard,
They have center stage, whether this ancillary subject of how to protect the slot from wear stays or goes. The reason we are talking about how to retrofit the slot is that Greg went to extraordinary lengths to repair the problem of a slot deformed by years of use, as his photographs early in the thread attest.

Regards
Timo

I acknowledge your point of view!
sincerely
richard

espressme wrote:I acknowledge your point of view!

We will have to get you an air-marshall's badge, Richard.

But seriously, I see the discussion of the deformed slot and how to prevent it as an outgrowth of Greg's restoration thread, not as a hijack.

Regards
Timo

A small back step here on a detail that might help those with the older style power switch.

Old Style switches are serviceable!!

So if it doesn't work- take it apart!

This switch is actually a double set of contacts that act like a relay. When I powered up for the first time- the light in the power switch lit up fine, but switching to the "on position" provided nothing. Before you start thinking you wired wrong, the element is burned out, the thermostat is tripped, or what ever you might think- use a OHM meter and see with the power off and unplugged that you get continuity from opposite sides of the switch when turn to the "on " position. If not- you may need to service the contact points.

If you remove the switch from the escutcheon, you will find that it is held together with one small 1" long screw across the back. Do not take the metal brackets of fthe front (rocker) part of the switch. There are little steel balls in it and they are challenging to re-install and almost impossible to replace- they are not the size of BB's! @#$%$%1! Unscrew this screw and the ceramic back portion of the switch will come off- ATTENTION!-make note of the up/down orientation - it can be installed either way.

Check out the points alignment and mating surfaces. You can unscrew the small screw holding one of the contacts, and leave the movable portion in place. This will allow you to polish the surface with some very fine sand paper- 400 or so. Back together in the reverse and check the continuity again before re-installing..

Sorry there is no accompanying picture- but the "Heads Up" was just to remind you to start with checking power at the source and move forward one step a t a time...

Ok- go get em LMWDP members!

No where was I? Oh, yeah, I was about to pull my first test shot and see if this was all worth it.