Snipe Problems on a Through Feed Moulder 1: Bottom Snipes

Checklist table of problems and solutions for moulder operators. December 1, 2006

Reprinted with permission from Diehl Machines, www.diehlmachines.com.

Troubleshooting Snipes on a Through Feed Moulder -
Bottom Snipes
Description
Probable Cause
How to correct


A snipe on the bottom of a finished part created by the second bottom spindle and on the leading end of the part.

Cutterhead is set higher than the out feed table.

Check the setting of the cutterhead with the outfeed table with a straightedge.

Outfeed table is too far away from the cutterhead.

Loosen the outfeed table and slid towards the cutterhead. Leave about 1/8" clearance between the swing of the cutterhead and the table.

Lower infeedroll is too high.

Set the lower infeedroll 1/32" above the infeed table.

Deep snipe from the first bottom cutterhead.

Check the setting of the first bottom cutterhead.

A snipe on the bottom of a finished part created by the second bottom spindle and on the trailing end of the part.

Cutterhead is set lower than the outfeed table.

Check the setting of the cutterhead with the outfeed table with a straightedge.

Bed plate under top spindle is too far away from the bottom cutterhead.

Loosen the bed plate and slid towards the cutterhead. Leave about 1/8" clearance between the swing of the cutterhead and the bed plate.

Lower outfeed roll is too high.

Set the lower outfeed roll 1/32" above the outfeed table.

Long stock is unsupported after leaving the moulder.

Place a table or conveyor under the stock to support it while it is leaving the machine.

A snipe on the bottom of a finished part created by the second bottom spindle and on either or both ends of the part.

Bowed stock fed into the machine with the bowed side down.

Increase the depth of cut on the first bottom spindle.

Increase the pressure on feedrolls and holddown to flatten the part.

Outfeed table is un-level with the rest of the bed plates.

Check the shims under the outfeed table for equal thickness. Check for dirt or slivers of stock under the table.

Deep snipe from the first bottom cutterhead.

Check the setting of the first bottom cutterhead.

The holddown is not parallel with the bed plates.

Use a dial indicator to adjust the holddown shoe.

Thin stock.

When running thin stock it is necessary to set the chipbreaker and holddown shoes as close to the cutterhead as possible without hitting the knives. Thin stock finishes better if the ends are kept butted up.

Snipe from the top cutterhead can leave the part loose.

Fix the snipe on the top first.

Holddown shoe is too short.

Slide the end of the holddown shoe over the leading end of the outfeed table. Use a longer shoe.

Unsupported pattern on the outfeed table. The pattern rotates to one or both sides.

Place a support on the outfeed table to prevent the part from moving.

Employee lifting stock to pull it out of the machine.

Solve the feed problem. Place a table at the outfeed end of the machine

See other articles in this series at:
Top Snipes
Left Side Snipes
Right Side Snipes

Reprinted with permission from Diehl Machines, www.diehlmachines.com.