30 mm Cage System Adjustable Mechanical Slits

Through Holes for 30 mm Cage System
Fine Micrometer Adjustment of Slit Width
Central SM05-Threaded Bore

Application Idea

VA100C Variable Slit with Attached SM05 Lens Tube in a 30 mm Cage System

VA100C

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Slit Nearly Closed

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View Imperial Product List

Item #	Qty	Description
CFH2	1	30 mm Cage Plate with Removable Filter Holder for Ø1" Optics, 8-32 Tap
CFH2-V	1	Variable Attenuator Insert for use with CFH2(/M) and Fiber Optic Filter Mounts
ER2-P4	1	Cage Assembly Rod, 2" Long, Ø6 mm, 4 Pack
TR3	1	Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
PH2	1	Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 2"
VA100C	1	30 mm Cage System Adjustable Slit, 8-32 Tap, Imperial Micrometer

View Metric Product List

Item #	Qty	Description
CFH2/M	1	30 mm Cage Plate with Removable Filter Holder for Ø1" Optics, M4 Tap
CFH2-V	1	Variable Attenuator Insert for use with CFH2(/M) and Fiber Optic Filter Mounts
ER2-P4	1	Cage Assembly Rod, 2" Long, Ø6 mm, 4 Pack
TR75/M	1	Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
PH50/M	1	Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=50 mm
VA100C/M	1	30 mm Cage System Adjustable Slit, M4 Tap, Metric Micrometer

The VA100C Variable Slit and the CFH2-V Variable Shutter in a 30 mm Cage System

Item #	VA100C	VA100C/M
Micrometer Graduation	0.001" per Division	10 µm per Division
Slit Width Adjustment per Rev	0.025"	0.5 mm
Slit Centering Tolerance	±0.003"	±0.08 mm
Mounting Hole Tap	8-32	M4

Features

30 mm Cage System Compatible in Vertical or Horizontal Orientation
1-to-1 Micrometer-to-Slit Width Adjustment
Slit Centered in SM05-Threaded (0.535"-40) Through Hole
Slit Width: 0 to 0.24" (0 to 6 mm)
Post Mountable in Vertical Orientation

The VA100C(/M) Mechanical Slit for 30 mm Cage Systems provides precise micrometer adjustment of the width of a slit formed by two A2 tool steel blades. This slit is mounted in a housing with four through holes for 30 mm cage system rods; each rod can be locked in place with setscrews using a 0.05" (1.3 mm) hex key or balldriver. When mounted within a cage system, these through holes allow the slit to be oriented either vertically or horizontally.

The slit itself is centered about an SM05-threaded through hole, and its width can be adjusted with a built-in micrometer. The unique design of this mechanism provides a 1-to-1 correlation between the adjustment of the precision micrometer drive and the subsequent change in slit width to within 0.001" (20 µm for the metric micrometer). The actual slit width ranges from fully closed to 0.24" (6.0 mm) wide with 0.025" (0.5 mm for the metric micrometer) of adjustment per revolution of the micrometer. In the fully closed position, the two blades are touching. However, imperfections in the blades and the degree to which the blades are parallel can cause gaps as large as 0.001" (25 µm) in width. The slit opening remains centered on the SM05-threaded (0.535"-40) aperture as the slit width is varied.

The slim profile of the mount makes it ideal for use with compact optical assemblies, and the black finish of the housing and the blades limits unwanted reflections. The bottom-located mounting hole is compatible with our standard Ø1/2" posts, allowing the slit to be mounted on a post in a vertical orientation. The through hole is SM05 threaded for compatibility with a variety of Thorlabs' products, including our Ø1/2" lens tubes. We also offer standard Adjustable Mechanical Slits that are not compatible with our cage systems.

Posted Comments:

zhi wang (posted 2020-06-22 10:12:26.143)

solid works file cannot be opened by solidworks edition 2013, do you have the iges/stp file type of the VA100C

YLohia (posted 2020-06-22 09:50:20.0)

Thank you for contacting Thorlabs. We will reach out to you directly with these filetypes.

eplingb (posted 2019-02-01 11:29:52.913)

I'm interested in using your Piezo Inertia Actuator to allow for remote control of the slits. What length of travel actuator should I get?

llamb (posted 2019-02-04 09:06:39.0)

Thank you for contacting Thorlabs. The variable slits on this page use micrometers with Ø1/4" smooth mounting barrels. Unfortunately the Piezo Inertia Actuators and our other motorized actuators do not have compatible mounting barrels, as they are typically either larger Ø3/8" mounting barrels or 1/4"-80 threaded mounting barrels. I have reached out to you directly to see if there are any suitable alternatives with your application.

cyprian.wozniak (posted 2018-01-17 09:35:35.567)

is there a motorized version of the actuators for this product (VA100C/M ) ?

tfrisch (posted 2018-01-17 11:41:31.0)

Hello, thank you for contacting Thorlabs. Unfortunately, we do not have a motorized actuator with the same barrel size (0.25") as the 148-202FT micrometer used in the variable aperture. I will reach out to you with the complete specifications in case you want to use your own motorized actuator.

kamzia1 (posted 2016-09-06 21:58:12.67)

Hello, I have question about this product. What is the thickness of blade edge? I mean width of terminal section of blade. in step drawing file it is drawn as 0.015 in (381 micron) Is this the real thickness? Or is marginal part ommitted? We want slit of 200 micron gap with edge as thin as possible, might be under 1 micron. If the blade is sharp enough we would consider this product as possible option. Please alarm me your specificaion. Sincerely Ji-Hyoun Kim

tfrisch (posted 2016-09-08 08:55:53.0)

Hello, thank you for contacting Thorlabs. 0.015" is the nominal dimension before accounting for manufacturing tolerances. I will reach out to you directly about your application and whether a precision mounted slit may be useful.