Saturday, July 21, 2012

Whirlpool Dishwasher Won't Drain

Odds are that the reason a dishwasher won't drain is that its drain check valve[1] is clogged with debris. The check valve is fairly easy to get at and deal with. You'll need a No. 2 Phillips screwdriver, a set of Channellocks, and something to use for a drain pan.

Remove four screws to get the two access covers off the lower front. Set your drain pan in place, and back off the big spring-type hose clamp from the rubber elbow you'll see at the end of the check valve. Slip the rubber elbow off the end of the check valve and you'll likely have this.

A slow dribble of murky water. If the water gushes out of there freely, the check valve is not the problem, and a 'Plan B' is in order.

Patience is needed here. It took four half-fillings of that big frying pan to completely drain the dishwasher.

With the draining over with and everything cleared away, it's fairly easy to unscrew the check valve to examine it. Here's a view of the check valve out of the appliance.


That thing's inside diameter is only 10mm, so it doesn't take much to clog it. Here's what I yanked out of it with a spring hook.


I have no idea what that grotesque little object is -- it's quite hard, and it's certainly not something that we eat around here. Whatever it is, it had no business getting into the dishwasher. This is why the very first thing the user's manual tells you is, "Scrape large food soil and hard items (toothpicks or bones) from dishes."

Anyway, with the check valve and its gasket-seating surfaces cleaned, everything went back together easily. Before replacing the access panels, I ran a 'fill' and 'drain' cycle to check for leakage. All was well, so the dishwasher is good to go again.

- - -

Note:

[1] As I understand it, the drain check valve is there so that in the event of some freakish mishap with a sewage system (as might occur in a flood, say) sewage water can't back up into the appliance. That's an excellent reason for the check valve to exist, but it does make for a somewhat constricted drainage opening.

The actual 'valve' inside the part pictured above is just a resilient flapper-valve located at the point where the diameter increases. I tried blowing through the valve in the 'check' direction, and it leaked, so how much good the valve would do if it were ever actually needed is questionable.

# # #


# # #

Sunday, July 15, 2012

A Wire Wheel Machine


I often refer to 'wire-brushing' when I write about restoring old gear. By 'wire-brushing', I seldom mean the use of these.



What I'm usually referring to is the use of this machine.



I'd be lost without the thing. It gets a lot of use here.

I built it many years ago from a 1/3 hp motor, and a ball bearing mandrel that I think I found at Canadian Tire. No one seems to make these ready-to-go; you pretty much have to construct your own to have one.

The drive ratio is approximately 2:1, so the no-load wheel speed is about 3,600 rpm.

The wheel is a fairly stiff 6" diameter one. 6" is an adequate wheel diameter, and that wheel has served me well. 8" would be better, though, and I mean to get an 8" wheel for it eventually. (When I was constructing the machine's base, I made sure to provide clearance for an 8" wheel.)

The safety police would likely taser me for that exposed v-belt drive, but there are no kids around here to worry about, and I can't be bothered making a belt enclosure for it. Different circumstances might dictate that a belt enclosure should be provided.

The one safety feature I did install was a guard for the on/off toggle switch, like so.


I fabricated that from sheet aluminum. It precludes inadvertently hitting the switch at an inopportune time.

Further to safety, don't even think about turning on a wire wheel machine without wearing eye protection. No necktie, dangling draw-cords or loose shirt sleeve cuffs, either.

Anyway, it's an indispensable item for repair and restoration work, and not difficult to construct. Google "ball bearing bench mandrel" and you'll find mandrel suppliers.

* * *

Update -- FRIDAY, APRIL 18, 2014

I finally got an 8" wheel for the machine. Here it is installed.


The wheel is from Busy Bee; Cat. No. B355.

The wheel's bore is 32mm. It comes with a set of molded plastic bushings for adaptation to fractional inch shaft diameters, like so.


Sizes are 1/2", 5/8", 3/4", 7/8" and 1".

The wheel runs reasonably true and balanced, in spite of the hub's somewhat wobbly appearance on the mandrel. The wheel's balance is not perfect -- it generates some vibration, but it's tolerable. The wheel is rated for 4,500 rpm, so my 3,600 rpm machine is well within that. (3,600 rpm seems to be a good speed; I wouldn't run one of these wheels any faster.)

The wire ends' finish at the wheel's periphery looks a bit haphazard -- it's not uniform -- but that doesn't seem to be a problem. If anything, it imparts a 'light aggressiveness' to the wheel that's actually a good thing in operation. The wheel also moves a lot of air -- there's quite a breeze that comes off it.

One little quirk I've encountered is that the wheel occasionally has a wire break partially free, and extend about an inch. When one of those wires strikes an ungloved finger, you really feel it. You have to stop the machine and snip off the offending wire. It doesn't happen often, and I imagine the effect may cease in time as marginal wires get culled.

My machine's 1/3 hp motor has proven quite adequate for the bigger wheel, but beware of motor horsepower ratings -- not all 1/3 hp motors are created equal. I recently built another one of these machines to give to my son, and the 1/3 hp motor I used for it is not nearly as powerful as the one on my original machine -- it's easily bogged down when running the 8" wheel. I'll likely have to get a 1/2 hp motor for that machine, to be certain of adequate power.

Anyway, the Busy Bee 8" wheel is of reasonable quality for the money, and does what it's meant to do.

- - -

Update -- Beware of Busy Bee's B355 8" Wire Wheel -- SUNDAY, JULY 6, 2014

I bought a second B355 wheel to complete the machine for my son, and the wheel is not good. It's badly imbalanced, and imparts severe vibration to the machine. It's going back to the store.

I'll update this post with the outcome of my dealings with Busy Bee over this.

- - -

Update -- Busy Bee Gets Their Wheel Back -- TUESDAY, JULY 8, 2014

I took the wheel back to Busy Bee, along with the machine I'm building, so I could demonstrate the defect, and test an exchange wheel before taking it home. The people at Busy Bee were good enough to let me set up the machine in back for a demonstration, and we tried out all three wheels that they had in stock. All three wheels were imbalanced and worthless.

I got a refund for the wheel I had bought, and went across the street to Markham Industrial. They had a Jet wire wheel for about three times the price of Busy Bee's wheel. I bought the Jet wheel. (Jet Prod. No. 550142: 8" medium wire.)  Here's a view of it still in its package.


The wheel's appearance is much better than that of the Busy Bee equivalent. We'll see how it runs.

I can only conclude from all this that Busy Bee's B355 8" wire wheel is a poorly made piece of trash. It's only by sheer dumb luck that you may get a useable one.

- - -

Update -- Jet Wheel And Second Machine -- SATURDAY, JULY 12, 2014

The Jet wire wheel is a decent piece of gear -- it runs fine. Here's a view of it mounted on my nearly-completed second wire wheel machine.


That machine has turned out so well, I may give it all a proper paint job.

* * *

Drivetrain Notes -- FRIDAY, DECEMBER 21, 2018

Just to have them recorded, I thought I'd list the drivetrain specs here.
  • Motor Pulley: 3" diameter.
  • Mandrel Pulley: 1 1/2" diameter.
  • Belt: 4L280.
Following are no load speeds with the wheel mounted, as measured with a digital photo-tachometer:
  • Motor: 1,750 rpm.
  • Mandrel: 3,285 rpm.
Note that mandrel speed is well short of twice motor speed. Given the 2:1 pulley diameter ratio, one would expect mandrel speed to be 3,500 rpm for a 1,750 rpm motor speed, but it's not.

There's a great deal more to V-belt drives than meets the eye. If you're interested, this article delves into some of the intricacies of calculating effective belt length, which bears on the subject of effective pulley diameter. Seemingly simple things have a way of getting a mite complicated in short order.

# # #


# # #