A (Epic?) journey in search of my perfect roaster

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Well FB, Im definately having a *time with it. Itll be a *fantastic time when Im drinking the results of its working. This is of course assumming I make it that far with-out blowing myself up in the process! ;D

Java "Having a *time of it!" phile

[Dimal]

Re: A (Epic?) journey in search of my perfect roas

Hey Mal,

What puzzles me with this motor is that it clearly states on its tag that it is designed to run at 127v. Now as far as I know there is no 127v 3-phase power, which means it appears to be set up for both single phase and 3-phase.

What this is actually referring to Java is that in its current connection configuration, the Motor is connected to run in "Star" which allows for starting the motor with minimum impact on the immediate surrounding power grid. Ive attached a basic Electric Motors explanation PDF file so you can see what this means in visual terms. It is not possible with this type of motor, to connect it to a single phase system and have it run "in balance", both in terms of electrical and mechanical aspects. This requires a motor that is specifically wound and with connection options to allow such a method of operation to be possible... not very common I can assure you.

In re the 50Hz vs the 60Hz this is what I was told was changed in the motor (I dont know enough about motors to know what this involves).

There is nothing in a 3-Phase or 1-Phase motor design that can have an effect upon the frequency of the supply grid, or visa-versa. To alter a motors operating characteristic from one particular frequency to another in order to maintain the same output shaft speed would need a complex motor design to accommodate this and would not normally be considered due to the extra expense involved.

My reasoning has been that even if it is still set up for 50Hz and with it being designed to run on 127v if I hook it up to a 120v/60Hz supply the increased frequency and the decreased voltage will hopefully cancel each other out to result in roughly the same performance as running on 127v/50Hz.

Its actually the other way around Java... to maintain the same output performance from the motor when switching from a 50 Hz supply to a 60 Hz supply, the terminal voltage would need to be increased, not decreased. This is because as the frequency is increased, the impedance (resistance) of the motor winding increases, which causes the motor winding current to decrease along with output power and torque capability. The terminal Voltage would have to be increased to approx. 150V per phase to achieve anything like nameplate outputs.

Another problem (maybe?), is that the output speed of the motor shaft increases (roughly) in proportion to the increase in frequency. So you could expect the motor to run at approx. 1,700 RPM at no load. This is presupposing of course, that you can supply the motor with the prerequisite 3-Phase 150V supply that it would need to run at all.

I plan on pulling the rest of the roaster apart here on Sunday to get it ready for the sandblasting on Monday and at that point Ill know what the shaft diameter on the motor is along with its length. Then I can start shopping around for a replacement motor for it in case it turns out the current one is not capable of being reconfigured for single-phase.

I think this will work out to be the best (and only) option in the end.

Suppossedly the sellers electrician will be back on Monday and hell be sending me the details on what was changed on the motor and hopefully how to reconfigure it for 127v.

Java "Cant wait to get it going" phile

Wish you all the best with this aspect of the upgrade Java and if you find out a method that really does allow you to run the motor as a single phase motor, I would appreciate the feedback.

Cheerio,
Mal.

P.S. :-
Something else that might be worth investigating if you know someone in the motor rewinding trade, is to find out if the original motor can be rewound to a 4-Pole, 1-Phase, Capacitor Start configuration. I have done this kind of thing myself where the original motor design allowed for it, so it might be another option?
Also, here is a link to a webpage... http://tinyurl.com/45eyd that explains the only reliable method that I know of that will let you run a 3-Phase motor from a 1-Phase supply. In the end, you would probably be better off with a new 1-Phase motor or the option above.

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Yeah Mal, its looking more and more like Ill either have to go with a rotary converter, a new motor, or a rewinding of the existing one. Hhhmmmm...

On the disassymbly front it is now painfully obvious that the barrel assembly will not come apart with-out some *serious long-term soaking in a penetrating oil. Seeing as this is not an option Ive determined to go ahead with the sandblasting with the barrel assembly intact. Both the inside and the outside of the barrels can still be blasted but the shaft area of the barrels and the top of the inside of the outter shield over the barrels will not be blasted.

This will result in some rust being left behind no doubt but in areas where it wont affect the roast.

The paint will be removed from all areas where it might affect the roast with all of the roasting/barrel assemblys being completely paint free.

Java "Arent projects fun!" phile

[FrenchBean]

Re: A (Epic?) journey in search of my perfect roas

Java

From what I could see in the photos the pully on the motor side of things looks like its not that big, thus (Im prob wrong here) the power requirement on the motor isnt going to to be that great, why not just get a 1ph motor and throw it on, doesnt it just rotate the drums? If you need to have an allowance to start up the motor without rotating the drum, have a look at putting on a clutch set up, similar to the cluth setup on Air Condinioer compressors in a motor vehicle.


A couple of different mounts arent going to be that much of a problem are they?

Just a thought thats all... (Ive prob made a complete goose of my self so to those of you laughing.. Your welcome ;D )

FB

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Hey FB,

The shaft off the motor with the drive (small) pulley wheel on it continues past there and into the turbine housing where there are large, heavy steel blades attached to it.

Im sure its because of this large mass on the end of the shaft that the motor has such large over-size bearnings. It will be interesting to see just how well balanced the turbine is once I get a working motor attached to them. At 1420 rpms I would imagine it would have to be pretty finely balanced or it would quickly tear itself apart.

Its also because of this large mass that the diameter of the motors shaft is so critical. It *must have a tight fit inside of the shaft with the pulley wheel and turbine blades on it. If its not a tight fit the motors shaft will be off-center from the center of gravity of the turbines shaft with disasterous results.

With everything properly lubed up and balanced I dont see the need for a 3-phase motor except at start-up, and that I think can be off-set just by giving the larger pulley wheel a good spin as you power on.

I plan on checking into single phase motors for it tomorrow as well as the possibility of having it rewound.

Java "Phase me in Scotty!" phile

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Well the motors shaft is either 15/32" or 12mm. It measures out at .470" with my dial vernier calipers which have not been calibrated in many years but should be accurate to +/-.001".

Java "Hhhhmmm...Which way do I go, which way do I go..." phile

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

GGGGGrrrrrrrr....It appears I wont have the roaster back from being sandblasted until next week. It was suppossed to have been picked up today but I just got a call from the blaster saying he wont be here to pick it up until Thursday.

On the up side it appears he needs computer work done and he also does painting as well as blasting so I may just have him paint the inside of the roasters box once hes done blasting it.

Java "If its not one thing its another" phile

[Dimal]

Re: A (Epic?) journey in search of my perfect roas

Hi Java,

You just know that all the trouble is going to be worth it in the end when youre sitting back, enjoying one of many great brews freshly roasted on your fully recommissioned roaster ;D.

Gotta love it...

Mal.

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Indeed Mal, thats what keeps me going. That and the thought of driving the whole neighborhood nuts with the smell of roasting coffee! ;D ;D

Java "Cant wait to get it going" phile

[robusto]

Re: A (Epic?) journey in search of my perfect roas

Another upside Javaphile is that had the machine been in pristine ready-to-use condition you many never have learned as much about it as you now know. And that knowledge has to be useful when it finaly fires up.

Ro "waiting with baited breath for first roast" busto

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Even in pristine condition Id have taken it all apart. ;D ;D

Java "Its what I do!"phile

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

Well the Sandblaster just left and it appears Im going to have to find a Powder or Soda blaster.

I spent a half hour or so going over the roaster with the sandblaster guy and his conclusion was that he (nor any other sandblaster) couldnt blast the roaster and preserve the metals finish. In order to do that he said Id have to have it powder or soda blasted which is apparently quite a bit more expensive.

Because of the added expense of this process and the potential cost of getting the motor working I will most likely go with a minimal blasting, cleaning off just the areas that are required for producing a clean roast and leaving the rest of the roaster until Ive managed to build my Toy Fund back up after it was emptied aquiring the roaster.

So its back to the drawing board and a hunt for a local person/company who does powder/sodablasting.

Java "My fingers are getting tired of all this walking!" phile

[robusto]

Re: A (Epic?) journey in search of my perfect roas

So frustrating, Javaphile. So close.

I dont supose you can go back to plan A -- use paint stripper to remove the paint from the roasting chambers? Its hard to tell from the pics, but is it possible to remove the 3 chambers and strip the paint (either with stripper, sandpaper or sand blasting) and then have them powder-coated or vitro-enameled?

Well follow your progress with much anticipation.

[Javaphile]

Re: A (Epic?) journey in search of my perfect roas

So frustrating, Javaphile. So close.

I dont supose you can go back to plan A -- use paint stripper to remove the paint from the roasting chambers? Its hard to tell from the pics, but is it possible to remove the 3 chambers and strip the paint (either with stripper, sandpaper or sand blasting) and then have them powder-coated or vitro-enameled?

Well follow your progress with much anticipation.

At this point Ive given up on taking the chambers apart into their component pieces. From Im sure many factors including age, constant heating with gas and then cooling, and the usage of mainly cast iron and mild steel parts all the screws and different pieces are well and truely welded into place.

The only way I *ever see them coming apart would be to remove all the paint and surface rust and then soak the whole thing in a penetrating oil.

One of the barrels set screws is missing so I attempted to remove the barrel from the shaft. I poked, and I prodded, and I beat on it with everything up too and including a 2 pound sledge until I was afraid I was going to destroy it. The net result? Nothing. Nada. Ziltch. The two pieces never budged one little bit. And this was in an area with no paint.

Ive also discovered under the paint that at least one barrel has had its gear brazed/welded to the shaft. Apparently the set key got lost so they welded it into place. This doesnt affect its usability at all but it certainly makes it harder to disassemble.

Im afraid that this poor roaster has led a tough life being operated by people who really didnt understand the mechanices of it, didnt know the meaning of the word maintenance and used the cheapest and easiest method available to fix it when they lost parts to it.

Notice I say "when they lost parts to it". From everything I have seen so far nothing appears to ever have broken on this machine, with the possible exception of the middle barrel which looks to have been replaced in toto. *Every problem I have found with it is due to a lost part or poor maintenance.

The good news is that none of these problems will prevent it from being returned to full usability.

The bad news is that it will take quite a bit of work and a moderate additional investment of $$ to put it into usable condition, and a sizable investment of both time and money to put it into a condition where it will last for another 50+ years.

I can live with it being just usable, but I like to restore my equipment to original or better condition. Unfortunately the Toy Fund wont support that kind of an outlay at this time.

My main concern for the longevity of the roaster is its main box which appears to be made from a thick gauge sheet steel which was then either plated with something (such as being tinned or galvanized) or possibly just given a coat of sealer/paint inside and out. With-out stripping some of it down I cant tell for sure if it was plated or not. From what I can see the box appears to be in very good condition with no signs of any major rust problems with the exception of parts of the walls of the flame chamber where the factory coating has worn off and surface rust has set in.

I plan on taking care of that problem with the sodablasting to remove the rust and old coating where upon I plan on painting it with an 1,800F rated paint which should be enough to protect it against anything short of direct flame application, which should never happen.

With that being done I have no doubts that the box would last for another 10 or 20 years, however, Id like to still be using this roaster in 40 years and be able to hand it over at that time to my kid knowing that itll last the rest of her life as well.

In order to do that though I will have to completely strip the main box right down to the metal inside and out and then have it coated inside and out with something that will prevent it from rusting under high temp and humidity conditions. The hard part of doing that is the purely interior panels and channels in the box. The box is not screwed together but rather is welded together so it cant be taken apart for easy access with one channel being virtually totally inaccessible. Because of this it will have to be acid etched to remove any current coating and rust and then most likely plated with a protective coating (Hhhhmmm....a chrome plated box! ;D). A pricey process, especially for something that big. Id have the roasting chambers and all the other parts done at the same time.

The construction of the box is simple enough that it may actually be cheaper to have a new one made from stainless steel than to try to restore the original. Such is not the case with the roasting chambers however with all their cast and rolled parts. With their *much thicker construction however theyre in no danger of rusting away any time soon or even most likely in my lifetime given even half-a$$ed care.

Given the high cost of doing a complete restoration/rebuilding and the current hollow sound from the Toys Funds piggy bank I think my best bet is to leave the box alone for now except for the areas of immediate concern in the flame chamber and to put what money there is into removing the paint from the roasting area and getting a working motor for it so that its usuable and worry about a lifetime rebuild in a year or two when the piggy is smiling once more.

Java "Arent Toys *fun?!" phile

[wattgn]

Re: A (Epic?) journey in search of my perfect roas

Java:

Mmm. It is like restoring an old aircraft, a job for someone with full shop facilities.

Like you say to strip it right down and restoring every bit and piece is like restoring some vintage aircraft or automobile. It would take a trained engineer some time to do, a labour of love.

I used to go flying, in a previous life, gliders and powered aircraft. I found that there were two types of people, those that loved flying and those that loved building. Not mutually exclusive but the ones that loved flying would build as a means to an end and most didnt bother (like me). The ones that loved building would keep building and would quickly get bored once they started flying what they built so theyd sell it and start building again!

Yes, you need some caffeine from this machine!

Grant