Why did my scroll saw die? Capicitor failure but why

[tom suica]

So I found a Delta ss200 at a garage sale. Guy wanted 85 I offered $10 then he said 25 I said 15 plus $5 for the swing set and that made another $20 bill making $40 spent total the other $20 was on 6lb of sterling silver tea set they obviously thought was plate.

I am kind of a garage sale shark...CHOMP CHOMP!

Anyway,

I was cutting on some 3/8 pine planks and was taking it really easy on the machine letting the blade do the work I cut out a small kitty cat and then another kitty cat 387556 more intricate this time (See Pics) then a small puzzle.387554 I probably put 30 min of time with some small breaks in between. Suddenly the motor was warm and started to smell a bit. I Know all about duty cycles and giving a machine a break but the machine had very little use on it and was pretty unused. Not saying it was new I think it was a 2003 model. How long can one typiically use this machine before giving a rest. Was it just old is that why the capacitor melted?? I also took the arms off the pivot hings and cleaned them out and re greaded the pivots with green grease now, also adjusted the cam on the motor so it was aligned better and reduced as much friction as possible. But it still needed help starting and no power like before.

I took the switch plate off and what's this? Melty crapacitor (see pics for melted capacitor387555) were my 3 small projects back to back too much for this machine or did its age and old components cause this?

In one of the arms there was some brass melt tiny tiny bit from the sleeve. It was obvious the hinges and hinge bolts were really really perfect conditon extremely low use () and just needed some oils so i wiped the melty brass away and then re greased man was it moving SUPER smooth after that.

[Mike Cutler]

Capacitors just go, at least that type does. Mylar and Tantalum will last quite a bit longer, 40 years is the life for Tantalum, but an electrolytic like that one is 10 years, give or take. Life expectancy installed is 5 years. Low use has little to do with how long they last.
Yes, capacitors do fail just like that. The dielectric compounds squeezes out of the case and makes a mess everywhere. They get hot and eventually "let the smoke out".

It was probably an old capacitor when it was originally installed. Even new, at 15 years old, it was way past it's "prime".

[Doug Dawson]

Capacitors just go, at least that type does. Mylar and Tantalum will last quite a bit longer, 40 years is the life for Tantalum, but an electrolytic like that one is 10 years, give or take. Life expectancy installed is 5 years. Low use has little to do with how long they last.
Yes, capacitors do fail just like that. The dielectric compounds squeezes out of the case and makes a mess everywhere. They get hot and eventually "let the smoke out".

It was probably an old capacitor when it was originally installed. Even new, at 15 years old, it was way past it's "prime".

Quality electrolytic power capacitors can and should easily last thirty years (unless you blast the crap out of them...)

It could just be a random failure.

Or: That the cap in a Delta _scroll_saw_ failed, says a lot about Delta's parts quality at the time of manufacture, as well as their engineering, and their respect for the buyer.

[Bill Dufour]

Most China made electronics they use components that are supposed to meet the specs with very little margin for error. A few percent off and they are two low a voltage to survive long. Also look at the labels many things are rated at 110 volts for some reason. North America switched up to 120 volts almost a century ago. At any rate, at least a decade before Edison died.
Also any thing made in China I do not trust the load rating. Just because the label says it is safe to lift two tons I would not trust it over one ton in my shop. That is my rule of thumb for Harbor Freight tools derate by about 1/2. Just like a sears motor horsepower rating.
Bill D

[Ken Fitzgerald]

Bill,

Since the saw is somewhat aged, you don't know that the capacitor was manufactured in China. 2ndly, like anything else, you generally get what you pay for and you can get quality parts and goods manufactured in China. 3rdly, it's been 30 years or more since "Made in the USA" was even a remote guarantee something was made with quality in mind.

In my experience, electronics parts including capacitors even those made in the USA, fail for a variety of reasons. While in the US Navy, I always had a part time "civilian" job to supplement my income for my family. Working in a couple tv repair shops, I replaced a lot of capacitors that failed in less than 10-15 years of age.

The reliability and quality of the supplied AC power can have a huge effect on the life of any electronic component. Later in my civilian career in electronics, I know of a machine costing around $1,000,000 that was installed in a city with poor power quality and the machine had a history of catastrophic failures. Eventually the customer demanded we take the system out. They installed a competitor's system and it ended up with the same poor history. The machine my employer pulled out was sold as used to a customer in Bozeman, MT where it performed quite well for a normal life span.

The environment in which an electronic component is operated can have a huge effect on the life of an electronic component. The environment includes the humidity or lack there of, the temperature, proper grounding and yes, the applied power.

I agree with Mike Cutler's statements.

[Mike Cutler]

Quality electrolytic power capacitors can and should easily last thirty years (unless you blast the crap out of them...)

It could just be a random failure.

Or: That the cap in a Delta _scroll_saw_ failed, says a lot about Delta's parts quality at the time of manufacture, as well as their engineering, and their respect for the buyer.

Doug
The capacitors that Sprague and Mallory used to make here in the US were nice, and if you can find them, they will probably outlast anything made in the past 20-25 years.
It used to be that if you opened up a capacitor, the dielectric compound was a uniform fill and density thought the capacitor. If you open up one manufactured now, it looks like someone shot a blob of RTV into one end. Even the Sprague's and Mallory's are that way. GE and Westinghouse still source good cap's but they're fairly expensive.
At work we give all of caps a 5 year shelf life and allow them to be re-formed once. Installed they're replaced on a 5-7 year cycle. For critical power supplies it's 3-5 years and safety categories are 5 years from the date code on the capacitor. no re-frming allowed.
Some of out GE Capacitors in non- critical power supply locations have been working since the early 70's, and still test "OK" for ripple. They'd fail a Sencor tester, but they're still "functional".
Our failure rate for newly received capacitors is probably 30-35%.
I'm not trying to be contrary, it's just that as manufacturing of electronic components moved out of the US, to Japan, taiwan, then Mexico, and now China, the quality just isn't there any longer. It's kind of sad actually. At work now we squirrel away the quality cap's that were once made in Mexico.

[Marc Jeske]

"Why did my scroll saw die? Capicitor failure but why"


Karma ?

?

Marc

[John McClanahan]

Frequent starting and stopping can shorten the life of start capacitors. A good example would be using a momentary foot switch on a capacitor start motor.


John

[tom suica]

I wrote 2 long winded responses last night both became erased. The first, I went to go make cat food then hit post and apparently it logged me out and my message was lost. Then the second one, I clicked reply to thread and suddenly my message became erased. VERY FRUSTRATING especially my smarty pants response toMark Jeske explaining to him that karma is defined as the "the sum of a person's actions in this and previous states of existence, viewed as deciding their fate in future existences." NOT things that happen in this life. The word he was looking for is causality. Or universal causality. Now I got smart copy the entire message and then click post.

[tom suica]

What did you want me to say? Excuse me sir this is solid silver and not buy it myself? It is one thing when a blind lady hands you 100's thinking they were 20`s you gotta say something. When someone has something priced at a yard sale and I negotiate a price down that is a fair sale. Don's speak misfortune on me Marc. Thanks for your response. Everyone else, I have to go to work and will come back and discuss more in depth my questions, and all your courteous responses and taking the time to answer my questions!!! Also I have more questions and will be uploading the details of the origin of the Cap!! I am excited as this unfolds!!

[tom suica]

387668 top left Globe with ZR inside Backwards RU with e193081 below it
Next line cbb60 s 14
10uF F +or-5% 50/60 Hz
250VAC 25/85/ UNREDBBLE LAST NO
NINGBO HAILIDA
2003.07

[Marc Jeske]

tom - I was just yanking your chain about the silver.


Marc :)

[tom suica]

I know big guy I wasn't upset... Welllll I wasn't too toooo upset I did get a bit sad and think perhaps I should have said something. Worried about my ower than normal empathy levels. I wanna be a good person. Y'know. :( I did/do feel for their ignorance. But she was also selling some Guatemalan worry dolls her friend gave her 15 years ago and I was like WHY ARE YOU SELLING THOSE. Oh we don't talk any more she said. So not really sentemental any more ad least.. I wish I had bought them. I cam back 20 minutes after showing my wife the Tea set to she sent me back to look for the sugar lid and the worry dolls were gone! DAMNIT

So also you flip something over and it says sterling and When I was like "wheres the lid for such and such" she was like "there was the cream thing the this the that and it seems weird but the other thing does not have a lid the set is complete" so she knew all about them just not their composition. I would understand if they were crackheads but they were homeowners in my on neighborhood perfectly sane and not handicapped or mentally challenged or anything both the wife and husband were there and clearminded and sober. Should I go back there? Bring them back or go give them some more $!? Was it some strange honor test from the illimaniti?!?!?! lolStrange how this conversation went from failed capitator to moral dilemma to conspiracy theory. As soon as I get a inute to ask my questions about capacitors /eletrotrolyc/start ect and more how they work and and some suggested reading on how to match uF ratings to motors and not ask anyhting too ignorant. I will seek the knolwedge by asking google i just ask if perhaps someone had some charts or some thing they learned on they would like to suggest to lil ol me.

[Bill Dufour]

I have to assume if the capacitor is 15 years old that is the age of the rest of the machine. I thought oil was used on the pivot bushings not grease?
Bill

[tom suica]

I have to assume if the capacitor is 15 years old that is the age of the rest of the machine. I thought oil was used on the pivot bushings not grease?
Bill
Excellent question. Looked like there were holes for something like sewing machine oil. Had "green grease the best grease money can buy. " on hand was planning on taking them apart and using sewing machine oil perhaps later. should be better than than the dry wear a tiny bit of the brass off nothingness there was before. again despite that tiny brass in the pivot there was no wear. I figured the machine was sticking and hard to start because lack of lube after i slicked everything up still hard to start then was trying to take motor apart and somehow i took the switch cover off oh yeah, because motor half wouldn't come off. I actually discovered bad start cap on accident. Just for your information.

There seems to be a lot of reading someteople use white lithium, some use Valvoline synthetic, wd40 silicone, some use dry lube. (Perhaps would be nice to grind up some pencil lead into those grooves. hell I dunno,)

I know all the theories about grease attracting abrasives. Proper test is to run all the lubricants on test models and run them for hundreds of hours under various conditions with various levels of maintenance seriousness and find a way to measure all the slop and give some general guidelines. None of us has cokecola funding to run such tests, soooooo I dunno what is really right and wrong.

[Marc Jeske]

Lubrication - Page 12 -

https://www.manualslib.com/manual/590738/Dewalt-Ss200.html?page=12#manual

Marc

[glenn bradley]

tom - I was just yanking your chain about the silver.


Marc :)

I thought the Karma joke was funny ;-)

Caps are inexpensive so, no big deal. I doubt there was anything you were specifically doing that cause the failure. I have caps in motors that have seen decades of use. My off-shore cyclone blew a few before I found the culprit to be a bad centrifugal switch. Easy fix. Enjoy your score.

[tom suica]

Now I think it is funny as hell and made a new friend! Mark! My buddy. Anyway, I have been watching vides on capacitors and start and run caps. The cap that was on it was that a start or a run? I feel like I am going to install a foot switch. Upon my limited knowledge and research, I feel like a more appropriate Cap would be a Run cap instead of a start cap as they are primarily used to start the motor and such. I also watched a run can bu sed as a start but not the other way around. Am I correct in assuming the run is better for the scroll application? Ah i see according to the ebay listing " https://www.ebay.com/itm/Polypropylene-Film-Cylinder-Shaped-CBB60-10uF-Motor-Running-Capacitor-U5D2/183139199518?epid=1869197561&hash=item2aa3f26a1e:g:EjMAAOSwR65aseNK " this one is a start run and the other is a run https://www.ebay.com/itm/302751539875

Can someone please point me in the direction of some better or higher quality caps that are less likely to break in me also is there some suggested reading so I can correlate a uF reading and run speed on the motor?

[tom suica]

Furthermore there does not seems to be a way to navigate through this thread correctly can a mod please step in so all the messages go on the same page. Or page 1 then click on page 2 I think there were replies inside replies and those do not show the same way as on other forums I know.

[Mike Harkin]

Tom,

Towards the top of the page is a gray bar that lists View first unread -Thread tools - Search thread - Rate this thread - Display
Click on Display and change the mode to linear.

[Ken Fitzgerald]

Furthermore there does not seems to be a way to navigate through this thread correctly can a mod please step in so all the messages go on the same page. Or page 1 then click on page 2 I think there were replies inside replies and those do not show the same way as on other forums I know.

Tom,

In the upper right corner of this page, click on "Settings". When the Settings page opens, scroll down. Watch the left side under "My Account" and select "General Settings". On the General Settings page scroll down to "Displayed Thread Options". There select "Oldest First - Linear". That will cause all of the threads you read to be displayed with the oldest post first, in a linear fashion.

After you make a change be sure to scroll to the bottom of the page and click on "Save Changes".

[Brandon Thill]

Can someone please point me in the direction of some better or higher quality caps that are less likely to break in me also is there some suggested reading so I can correlate a uF reading and run speed on the motor?

mouser.com has a good selection. I just bought Kemet and TDK caps to replace the start and run caps on my bench sander. You can filter by start/run for fast results.