Dayton Die Cushions - Forming Speed

The velocity of the press ram must be determined at the point on cushion contact. On a hydraulic press, this is the velocity of the main press stroke and is constant throughout the stroke. On a mechanical press, the ram velocity is constantly changing and must be determined individually for each press.
Special type of RAPID die cushions have been developed for high speed forming.

Catalogs

Model C

Model D

	Maximum Allowable Linear Speeds
Cushion Size	All Steel Cushion	Rapid Die Cushion
10" dia.	125 ft/min	185 ft/min
12-16" dia.	100 ft/min	150 ft/min
18-22"	75 ft/min	110 ft/min
24-30"	60 ft/min	90 ft/min

	Maximum Allowable SPM Formulas
Cushion Size	All Steel Cushion	Rapid Die Cushion
10" dia.	478/S	707/S
12-16" dia.	382/S	573/S
18-22"	287/S	420/S
24-30"	229/S	344/S

S - Press Stroke

SPM - Strokes per Minute

Formula to calculate maximum linear velocity of mechanical press:

Maximum Linear Velocity

(S x Π x SPM)/12

Formula to calculate linear velocity of mechanical press at any crank angle:

Linear Velocity

(cosθ x L x Π x SPM)/12

S - Press stroke in inches
L - Press stroke
SPM - Strokes per minute of the press
θ = angle of crank, in this case 50 degres

The cos(50) = .64 factor is the percentage of maximum linear ram speed derived from the maximum linear ram velocity formula. If θ = 0 degrees, its cos(θ)= 1, so the ram develops its maximum speed. At 90 degrees, cos(θ)= 0; there is no linear movement, the ram is at dead bottom.

Additional Information

Die Cushion Tonnage

Press Tonnage

Tonnage for drawing shells