Troubleshooting - Deschner Corporation

As part of our charter to offer the highest quality products possible. Each and every Deschner unit is tested prior to shipment. As our customers will attest, they are generally reliable and trouble free. However, there are occasions when our product is used in an unusual application; or the recommendations contained in our instruction sheets are overlooked, resulting in a poor performance or shortened service life . To help these customers we have prepared the following troubleshooting guidelines.

General Comments:

Please make sure you are using the proper model for your application. A Kinechek should not be used in a shock absorber application and a Cushioneer cannot be used as a constant velocity control.
The plunger rod on our products cannot be depressed by hand when set at approx 5 or higher on the scale line.
The rod should not be forcibly twisted within the body and then cycled or allow the moving load to slide across the end of the plunger rod causing the rod to twist during its stroke.
Make sure the moving load is aligned accurately to contact the plunger rod squarely during the entire stroke of the plunger rod and that the striking face is flat.
Do not use in ambient temperatures below +40°F (4°C) or over +130°F (55°C).
The capacity shown for each of our products has a built in safety factor. However, applications exceeding the published maximum rated capacity can be damaging to the unit and will reduce the service life.

Following are some common malfunctions and the probable causes. (Note: To avoid repetition, remedies are listed below.)

A Rod Hesitates or does not spring out fully

Ruptured seal resulting in fluid loss (remedy 1)
Bent Rod (remedy 1)
Twisted diaphragm (remedy 2)
Body ovalized below lower retaining ring groove caused by poorly fitting customer mounting block or excessive clamping force. (remedy 3)
Piston allowed to bottom out against adjustment knob face (remedy 4)
Bulged piston wedged in cylinder usually caused by exceeding maximum capacity or using a Kinechek speed regulator in a shock absorber application. (remedy 1)
Rod bushing filled with dirt, sludge, heavy grime, etc. (remedy 1)
Normally dry spring chamber filled with cutting oil or cooling fluid. (remedy 1)

B Rod will not move

Bent Rod (remedy 1)
Bulged piston wedged in cylinder usually caused by exceeding maximum capacity or using a Kinechek speed regulator in a shock absorber application. (remedy 1)
Twisted and balled up diaphragm. (remedy 1)
Slimline cap smashed and wedged against rod (remedy 1)

C Cannot adjust unit to meet requirements

Attempting to fine adjust at extreme ends of scale line and rotating adjustment into null area. (remedy 5 a,b,c)
Kinechek – adjustment knob won’t turn because it’s galled in cylinder (remedy 1)
Cushioneer – sheared pin in adjustment knob (remedy 1)
Mini K and/or Super K – casing forcibly rotated from home position (results in mislocated scale). Note: Set adjustment knob on “0”. If plunger rod does not depress easily by hand the casing is probably rotated. (remedy 6)
Mounting unit within 2″ of edge of Slimline body, at adjustment end, ovalizing body and cylinder causing adjustment knob to bind. (remedy 3)
Adjustment mechanism shifted by hammering on adjustment knob. (remedy 1)
Using screwdriver slot for indicator line instead of slot on side of Slimline adjustment knob. (remedy 7)

D Erratic speed regulation

Unit leaking and low on fluid (remedy 1)
Rod bushing filled with dirt, sludge, heavy grime, etc. (remedy 1)
Normally dry spring chamber filled with cutting oil or cooling fluid (remedy 1)
Slimline cap damaged causing cover washer to scrape rod (remedy 1)
Bent plunger rod (remedy 1)
Piston bulged and tight in cylinder (remedy 1)
Twisted diaphragm seal (remedy 2)
Ovalized body and/or cylinder preventing free movement of plunger rod assembly. (remedy 3)
Significant change in applied force during Kinechek stroke. (remedy 8)

E Shortened Service Life

Kinecheks
1. Rapid cycle rate with force in excess of maximum rated load.
2. Excessive or rapid free travel before moving load strikes plunger rod resulting in an impact force exceeding maximum capacity of Kinechek.
3. Use in harsh environment:
  1. Exposure to abrasive matter such as grinding slurry, glass dust, etc.
  2. Allowing cutting oils/cooling fluids to flow over unit or collect on rod.
  3. Operating in ambient temperatures below +40° F or over +130° F.
    Note: The Kinechek is running too hot if you cannot hold your bare hand on it for 2 full seconds. Cool unit with fan.
4. Use in application with swinging lever to depress plunger rod causing rod to twist (use of roller bearing will eliminate this problem).
5. Kinechek used as a shock absorber
6. Maladjusted or no solid safety stop to prevent Kinechek plunger rod from bottoming out.
Cushioneers
1. Impact load exceeds maximum capacity of unit.
2. Operating temperature exceeds +135°F.
  Note: The Cushioneer is running too hot if you cannot hold his bare hand on it for 2 full seconds. Cool unit with fan.
3. Rapid start up in ambient temperature below +40° F.
4. Cycling unit so rapidly that plunger rod does not extend fully before being impacted again.
  Note: When velocity of moving load exceeds 144″/sec. the diaphragm seal does not respond quickly enough causing excessive stress on the seal and a build up of internal fluid pressure leading to premature seal failure.
5. Maladjusted or no solid safety stop to prevent Cushioneer plunger rod from bottoming out.

REMEDIES

Return unit to factory for overhaul.
Remove unit from machine. Allow unit to sit for several hours to see if rod will unwind on its own. Turn adjustment knob to “1” on scale line. Depress plunger rod by hand. If rod quickly snaps out full stroke and there is no sign of leakage unit can be reinstalled in machine. Make sure moving load is aligned accurately with plunger rod.
Ovalization is usually caused by customers poorly fitting mounting bracket or by over torquing the mounting bolts. Note: Ovalized condition can sometimes be corrected if unit is installed in a different mounting or bolts are loosened.
Provide a solid safety stop adjusted to stop the moving load approximately 1/32″ (.8mm) before plunger rod reaches bottom of its own stroke.
1. If attempting to adjust near “0” on scale line:
  Cushioneer = Select a light duty model
  Kinechek = Select a faster speed model
2. Cushioneer = If attempting to adjust near “20” on scale line select a longer stroke model. (If already using a model 2002-31-2 the load is beyond the capacity of Cushioneers.)
3. Kinechek = If attempting to adjust near “30” on scale line select a slower speed model.
Remove unit from machine. Invert unit and place plunger rod on a flat, solid surface. Push down on unit and rotate adjustment knob until rod depresses easily. Without moving the adjustment knob from the easy setting, firmly clamp unit on its mounting surface and rotate the casing until the “0” mark on the scale line lines up with the indicator line on the adjustment knob. Make sure the casing is pushed up against the shoulder of the rod end clamp ring. Note: The adjustment may not be completely accurate but it will be within reason.
Readjust unit using indicator slot on side of adjustment knob. If still unable to adjust, return unit to factory for overhaul.
Make sure the applied force stays constant within plus or minus 3%.

We hope this information will be helpful for you. If you have questions or you encounter problems not covered by these guide lines please contact us before returning units. This could save you time and shipping cost.