Engineering DataGuided Keepers
Guidance and Retention - All-In-OneThis product may be covered by one or more patents or patent applications.
See http://www.standardlifters.com/patents.html for details. 12/13 - Rev. 6
Engineering Data - Guided Keepers - Pg. 2
Things to Consider
Machining Required to Mount the GK Base
Below are three factors that should be considered when choosing a Guided Keeper style for your design. We offer many different styles in order to provide the best possible solution based on your tool application, die build process, and personal preferences.
Machining Required to Mount the Guide Pin
Bushing Length
OR
OR
When the Pad is subjected to a side load, the Guide Pin makes contact with two primary areas (see red lines on thepicture to the left).The greater the distance between these areas, the less amount of movement that can occur. Longer Bushings are important on pads with long Guide Pins and/or long travel.A longer bushing provides more surface area making contact with the Guide Pin, which extends the life of the unit.At times adding 30% to the length of the bushing can double the life.
Machining - 1 setup
Holes would still need to be deburred by hand
after machining
Machining - 2 setups
Working Side Back Side Working Side Back SidePocket Machined on Back Side provides
location for Guide Pin
Location: Bore Hole
Drilled Hole
Location: Reamed Holes
GK120-L2 = $90.75
*Most Economical Base Styles
vs. GK120-A = $120.75
Engineering Data - Guided Keepers - Pg. 3
If SL built tools we would use...Small ToolsGK120-L2
($90.75)
Here’s Why ...
Redundant screws in the Guide Pin Making it easier to assemble using one tap to hold the Guide Pin in place while installing the other
Medium ToolsGK180-L3
($122.25)
Large ToolsGK205-L4
($154.00)
Large Locating Diameter in the Pad Locating on the full diameter of the Guide Pin provides a great amount of surface area and support
Integral Flange on the BaseNo loose flange clamps that could be misplaced
Locked Base AssemblyRetaining Ring prevents screws from loosening during production
Engineering Data - Guided Keepers - Pg. 4
What we have found based on direct feedback from Metal Stampers:• It’s always more cost effective to start with a quality tool design rather than
re-engineer later on. If a Stamper needs to add a GK Unit(s) to an under engineered die condition it costs them 3-4 times as much as if the die was built with them originally.
• Pad applications that have a minimum of 3 or more GK Units compared to only 2 GK Units provides a much more robust application. The Pad is less prone to tipping, bushings last longer, and the assembly is stronger in a mis-hit situation.
Based on the facts above, it is important to design your tools with an adequate number of Guided Keeper units based on the application. Although it is hard for SL to make a recommendation on the number of GK Units to use for every application, we have created a matrix to help as a general guide. The matrix gives you a general guideline based on what we have found are “average” conditions. Please use this information, along with your discretion, to determine the number of GK Units to use in your specific application.
*SL provides these recommendations for the following reasons:• To save you time and money • To ensure your dies produce quality parts • To ensure press operator safety
Disclaimers:• This is only a Guide - Discretion must be used based on each die application in
regards to the number of Units to design in. It’s your responsibility to design a die that is adequately engineered.
• If there is known side load that will be subjected on the Pad, we recommend adding heel blocks.
• The calculations are based on a “standard” crank press cycle. If the press has an accelerated “up” cycle, such as a double action press or a programmable hydraulic press, then the number of Units used should be increased.
GK Application Recommendations
Engineering Data - Guided Keepers - Pg. 5
How we calculated the # of Units
Weight and Speed are the two main factors that generate Impact Forces. The weight of the pad is important, but even more crucial is taking into account how fast (SPM) the Tool will be running and how much the Pad will travel.
SPEED
WEIGHT
What affects Impact Forces
The speed of the Slide/Upper Shoe at the time of impact
Other data used in the calculation• 6-Times Safety factor for the GK Units - for fatigue• An average press travel, or slide stroke of 16” - 18” was used
The weight of the pad is a known value, but a much more advanced calculation is the speed of the Slide/Upper Shoe at the time of impact on the Guided Keeper. See below for this calculation explained in simple form...
One Press Cycle (revolution) - Standard “Crank” Press
Total Slide
Stroke
Press Speed Curve
Distance from Bottom Dead
CenterPad Stroke
Point of Impact(when the upper shoe
“Lifts” the Pad)
The speed of the Press Slide “ramps up”
The further up the curve the point of impact is located, the faster the
slide is traveling and thus increasing the impact force on the Assembly
Engineering Data - Guided Keepers - Pg. 6
Example: A 325lbs Pad with a 3” Pad Stroke and a press stroke of 40 SPM
Recommendation:• Qty of 4 Units• 1.25” Dia.
Guide Pin• 2” Bushing Length
Minimum Recommended Bushing Length
Minimum Recommended Bushing Length
Minimum Recommended Bushing Length
Engineering Data - Guided Keepers - Pg. 7
Minimum Recommended Bushing Length
Minimum Recommended Bushing Length
Minimum Recommended Bushing Length
Engineering Data - Guided Keepers - Pg. 8
If you would like Standard Lifters to run a calculation on your specific application please email us all of the information at [email protected]
Engineering Data - Guided Keepers - Pg. 9
GK Locking Collar - Accessory
O-ring maintains the radial location and
prevents collar from falling out during
disassembly
Tapered groove forces Retaining Ring down
which provides locking force to the
Cap Screws
The GK Locking Collar prevents screws from possibly coming loose and falling into the
tool during operation.
Machining Required: Simple Round Pocket
Note: This is an optional accessory that some stampers require in their tools.
*Available for GK205 and GK180 Series Guide Pins
Engineering Data - Guided Keepers - Pg. 10
Application Tips - Prevent Tipping• Apply Stand-offs to pressure pads & lifters to maintain parallel (“flat”) travel.
Pad tipping breaks screws, wears out pins/ bushings, and gas springs.
• To ensure the Pad/Lifter does not tip during the working stroke, apply enough pressure to keep it balanced and flat.
• Applying pressure in a balanced pattern will safeguard the pad from tipping.
Punch Shoe
Die Shoe
Pressure Pad
Lifter
Partial Stock
Stand-offs
Engineering Data - Guided Keepers - Pg. 11
Application Tips Cont...
Offset pin to fool-proof assembly
• Offset one Guided Keeper location or use different diameter pin as methods to fool-proof the assembly.
• Use a minimum of three Guided Keepers per Pad... this condition has proven to be more robust. The Pad is less prone to tipping, the bushings will last longer, and the assembly is stonger in a mis-hit situation.
Engineering Data - Guided Keepers - Pg. 12
Product # StructureGK Series Base Style English/Metric Pin Length
GK120 L2 E 4.25Example: GK120-L2-E-4.25
Guid
e Pi
n Le
ngth
Determines Taps and Reams in Guide Pin End
Primarily determines any Fasteners, Taps,
Reams in the Base
Measure to the Steel Shoulder not the
Dampening Washer
Base
s Ava
ilabl
e
Base
Loc
ation
Met
hod
Bore
/ B
ody
Ream
s / D
owel
sBu
shin
g Le
ngth
2.00
”3.
00”
4.00
”2.
00”
3.00
”1.
25”-
1.50
”2.
00”
3.00
”
Guid
e Pi
nSe
ries
Add
per
.125
”L2
L3L4
H2H3
AD2
D3G
K70
(.75”
)$.
25$7
8.25
(2.3
75”)
$80.
25(2
.375
”)$9
0.00
(1.6
25”)
$95.
25(2
.375
”)
GK7
5(.7
5”)
$.25
$78.
25(2
.375
”)$8
0.25
(2.3
75”)
$90.
00(1
.625
”)$9
5.25
(2.3
75”)
GK9
5(1
.00”
)$.
75$8
1.50
(2.5
00”)
$91.
50(3
.500
”)$8
5.50
(2.5
00”)
$95.
50(3
.500
”)$1
05.5
0(2
.500
”)$1
15.5
0(3
.500
”)
GK1
05(1
.00”
)$.
75$8
1.50
(2.5
00”)
$91.
50(3
.500
”)$8
5.50
(2.5
00”)
$95.
50(3
.500
”)$1
05.5
0(2
.500
”)$1
15.5
0(3
.500
”)
GK1
20(1
.25”
)$.
75$9
0.75
(2.3
75”)
$100
.75
(3.3
75”)
$94.
75(2
.375
”)$1
04.7
5(3
.375
”)$1
20.7
5(2
.125
”)$1
14.7
5(2
.375
”)$1
24.7
5(3
.375
”)
GK1
50(1
.50”
)$.
75$1
01.7
5(2
.375
”)$1
11.7
5(3
.375
”)$1
05.7
5(2
.375
”)$1
15.7
5(3
.375
”)$1
25.7
5(2
.375
”)$1
35.7
5(3
.375
”)
GK1
75(1
.75”
)$.
75$1
10.7
5(2
.375
”)$1
20.7
5(3
.375
”)$1
15.7
5(2
.375
”)$1
25.7
5(3
.375
”)$1
42.2
5(2
.125
”)$1
35.7
5(2
.375
”)$1
45.7
5(3
.375
”)
GK1
80(1
.75”
)$.
75$1
12.2
5(2
.625
”)$1
22.2
5(3
.625
”)$1
17.2
5(2
.625
”)$1
27.2
5(3
.625
”)$1
37.2
5(2
.625
”)$1
47.2
5(3
.625
”)
GK2
00(2
.00”
)$1
$139
.75
(3.3
75”)
$148
.75
(4.3
75”)
$145
.75
(3.3
75”)
$158
.75
(2.3
75”)
$165
.75
(3.3
75”)
GK2
05(2
.00”
)$1
$145
.00
(4.2
50”)
$154
.00
(5.2
50”)
$151
.00
(4.2
50”)
$171
.00
(4.2
50”)
Engineering Data - Guided Keepers - Pg. 14
FAQ• How do I determine the Guide Pin Length? Measure from the steel shoulder to the mounting surface, see picture on pg 12 of this booklet.
• Why aren’t the mounting holes on the L-bases in the same location for the English and Metric versions?
The English and Metric fasteners do not have the same head size. We wanted the head to be as close to the base as possible, so the centerline of the fastener is in a different location between the English and Metric versions. It also keeps the fastener under the Retaining Ring, thus preventing a fastener from loosening and falling out of the tool.
• Should I put grease or a light lubrication on the Guide Pin before running it? No. The Guided Keepers are designed to be run “dry”. A light lube is acceptable, but grease will pull contaminants into the base and cause premature wear to the components.
• Do you have English and Metric sizes available? Yes - Taps and Reams in the Guide Pins / Bases come in both English and Metric, but the Pin Length is always ordered in English.
• How many Guided Keepers should I use in my application? Refer to pages 4-8. “Determining the # of GK Units to Use”
• What base style should I use to save the most money? The L Series Base Style is our most economical base option, available in 2”, 3”, or 4” bushing lengths. L2, L3, L4 Base Styles • What length dowels should I install in the GK120/GK150 Guide Pin ends? The dowels are used only for location and should be kept relatively short to prevent them from breaking during assembly and disassembly. See the chart below.
Series Guided Keeper Units Dowel Diameter Dowel Length
GK120English 5/16” 3/4”Metric 8mm 20mm
GK150English 3/8” 1”Metric 10mm 24mm
Engineering Data - Guided Keepers - Pg. 15
Go Online for: CAD Models
Go Online for: Dimensioned Prints1. Go to www.standardlifters.com 2. Click on the Engineering Data Tab
3. Click on the Dimensioned Prints 4. Navigate to Desired Print (PDF)
1. Go to www.standardlifters.com 2. Click on the Engineering Data Tab
3. Click on the Cad Library 4. Click on desired CAD Model Type
Either Full Assemblies or Individual Parts
For New and Updated Informationwww.standardlifters.com