Slot Measurement
2021年3月4日Register here: http://gg.gg/oj7gw
I’ve been scouring the interwebs for PCIE slot measurements with mixed results. There are a few common graphics that pop-up each time this question is asked on various forums, but they are inconsistent and vary quite a bit. If you’ve ever searched for this measurement you’ve probably seen them yourself, if not, you can check them out here.Jeffinslaw, who designed the Project mATX case, also had this discussion on another forum and received a couple different measurements, as well as posting his own. And unfortunately, formfactors.org doesn’t have any resource that addresses this either.So I figured I’d pose the question here, and see if we can pin down a common measurement, or if we’re lucky, stumble upon the holy grail that is PCIE slot standard spec. I’ve added some sketches that cover the most important measurements for the slots, with one graphic depicting a top down view of the flange that pci cards are mounted to, and another graphic from an inside out view of the slots next to the motherboard IO.I’ll be sure to update this post for a record of all the different measurements that are posted.UPDATE - 5/4/17SOURCE: Protocase Technical Bulletin, Updated June 6th, 2011Thanks to [21CW]killerofallI didn’t add measurements for the distance between motherboard tray and bottom of PCI slots, but they are included in this paper, and use the standard 6-32 x 3/8’ motherboard standoff.
Slot definition: 1. A long, narrow hole, especially one for putting coins into or for fitting a separate piece into. The DSC - SP2000 Platforms provide data measurements on a per system and per slot (CPU) or virtual slot (VM) basis as described in the following figure and table provides an example for a file that includes such measurements. Note the separate lines containing data for system and for slot data measurements. The method we are using now is a surface plate setup in the quality lab, V blocks, snug fitting gage block stack in the slot, and indicated parallel with the plate using a height stand. Then the distance from top dead center and bottom dead center to the gage block stack is measured.Last update: 9/5/2016Those of you that have purchased or are considering picking up one of the recent Winchester Limited Series BPCR manufactured by Miroku have noted that many come without sights. The rear receiver tang is drilled and tapped for a sight and a female dovetail slot has been cut for installation of your preferred front sight. Most sight suppliers are familiar with the Browning BPCRs but may not understand that the more recent Winchester BPCRs are identical to the Browning’s including the dovetail slot dimensions.There are many sizes of dovetails. To get an idea of the various dovetail dimensions go to Brownells.com web site and search for dovetail cutters. In the following discussion I will limit my comments to dovetails on rifles, which is something I know a little about. In general there are three or four measurements that define the dimensions of a dovetail slot: the opening and end widths, shoulder angle and depth of cut. The width of a female dovetail slot is measured along the long axis of the barrel at the bottom of the slot, the widest fore and aft point of the dovetail. If the slot is tapered, the right opening, with the muzzle pointing forward, is slightly wider than the left end. The shoulders are angled inward and the slot is cut to a specific depth. If the slot is not tapered it was likely cut with a standard dovetail cutter. The two critical specifications of dovetail cutters are the width and the shoulder angle. The depth of cut is determined by the gunsmith or machinist. Therefore a 3/8” dovetail slot with 60° shoulders is 3/8” (0.375”) wide at the base and the angle from the base to the inside of each shoulder (or side) is 60°, which is by far the most common dovetail angle used in modern firearms.If you check with Browning or Winchester, they will likely inform you that the BPCR dovetail slot is 3/8” with 60 degree shoulders and is cut to a depth of 0.090”; all of which are accepted as an industry standard on modern firearms. But knowledgeable gunsmiths are aware that some factory barrel female dovetails slots are slightly oversized on one end and usually tapered to allow easier insertion of the male sight dovetail. In my book on the Browning BPCRs I measured several rifles and reported the range of dimensions. Nominally a 3/8” dovetail will measure 0.375”, but the right opening of the Miroku/Browning dovetails ranged from 0.380” to 0.384”. I recently checked the dovetails on several Miroku/Winchester BPCRs and confirmed approximately the same range. I also measured the left ends and found the width to range from 0.373” to 0.377”, confirming a slight taper. Therefore, be sure to follow the industry standard process of removing an existing sight by drifting it out from left to right and installing it from right to left. So how does one accurately measurethe dovetail width?If an existing front sight is being replaced the first thought may be, why not just measure the width of the base of the old sight with a conventional micrometer or caliper? The problem is that male sight dovetail bases are slightly rounded on the edges, if for no other reason than to remove the sharp edge for safe handling, resulting in a narrower dimension than the female dovetail slot. A recent example is a front sight I removed from a Browning BPCR. I found the right opening width was 0.385”, but the width of the male dovetail base of the sight was 0.376”. The next thought that may come to mind is to use the rear or inside measuring jaws of a caliper on the female slot. Due to the slight offset and edge thickness of the jaws, an accurate measurement is almost impossible. So what’s the answer? I’m no expert on dovetails, but there are four techniques that I’m aware of.If you expect to be cutting numerous dovetail slots and installing sights, one solution is to order a wire gauge dovetail measuring tool from Brownells. The current price of one made by XS Sight Systems (part # 006-101-000WB ) is $54.00 plus shipping. But the vast majority of shooters reading this article are not gunsmiths, and working with dovetails is not a common occurrence.Another method is to make a cast of the female dovetail slot using either Cerrosafe or epoxy. Once the cast is removed, measuring the width of the male dovetail cast is simple. I have not used this method but understand it works well as long as the Cerrosafe is removed at the proper time prior to enlarging and locking itself into the slot. If an epoxy cast is made, it should be relatively easy to remove as long as the dovetail is sufficiently coated with a release agent such as paste wax. By the way, never use a steel punch when removing and installing sights in dovetails. A brass punch will work but will likely leave a thin brass smudge on the sight surface. And always 1st check to determine if the sight utilizes a setscrew to lock it into place. I use a short section from a hard plastic Delrin rod and have yet to run into a sight that I could not remove or install.One quick technique that works that works for me is to utilize a slightly tapered gauge, cut with common scissors out of thin shim stock. The gauge width should taper from a dimension narrower than the slot to slightly wider than the slot. Sharpen the long edges of the gauge with a file or sandpaper. The gauge is pushed in by hand and ’wedged’ into the bottom of the female dovetail until it stops. Mark the gauge at the start of the dovetail, pull it out and “gently” measure the width at the mark with calipers or a standard micrometer. Carefully using this technique will result in an adequate measurement. And don’t forget to measure the opening and ending slot width, which will also provide the slot taper if any exists.The most accurate technique is to use a couple of precision steel pins of identical diameters, which are placed in the dovetail (refer to the figure below). The distance between the pins is measured with a caliper and used in the formulas below. Just ensure the diameters of the pins are small enough to contact the side of the dovetails below the top edge. A couple of 1/16” (0.0625’) drill shanks should work fine. Since the vast majority of dovetails have 60° shoulders, I’ve simplified the formula so you don’t have to figure out the cotangent of 30° (60°/2).Slot Width Measurement
*What is the ’standard’ method for dimensioning slots? We have for years located the slot by the geometric centerlines and described the slot size by note. For example: ’SLOT 9/16 X 1’. Some of us are wanting to locate the slot with the longitudinal centerline in one direction and by the ends of the slot in the opposite direction.
*In any high performance array, it is necessary to make careful measurements of single-slot admittance for a family of slot offsets and lengths. 36 shows the Stevenson resonant conductance, which is a function only of offset. Slot resonant length involves three variables: x/a, a/b, and β/k.
Register here: http://gg.gg/oj7gw
https://diarynote-jp.indered.space
I’ve been scouring the interwebs for PCIE slot measurements with mixed results. There are a few common graphics that pop-up each time this question is asked on various forums, but they are inconsistent and vary quite a bit. If you’ve ever searched for this measurement you’ve probably seen them yourself, if not, you can check them out here.Jeffinslaw, who designed the Project mATX case, also had this discussion on another forum and received a couple different measurements, as well as posting his own. And unfortunately, formfactors.org doesn’t have any resource that addresses this either.So I figured I’d pose the question here, and see if we can pin down a common measurement, or if we’re lucky, stumble upon the holy grail that is PCIE slot standard spec. I’ve added some sketches that cover the most important measurements for the slots, with one graphic depicting a top down view of the flange that pci cards are mounted to, and another graphic from an inside out view of the slots next to the motherboard IO.I’ll be sure to update this post for a record of all the different measurements that are posted.UPDATE - 5/4/17SOURCE: Protocase Technical Bulletin, Updated June 6th, 2011Thanks to [21CW]killerofallI didn’t add measurements for the distance between motherboard tray and bottom of PCI slots, but they are included in this paper, and use the standard 6-32 x 3/8’ motherboard standoff.
Slot definition: 1. A long, narrow hole, especially one for putting coins into or for fitting a separate piece into. The DSC - SP2000 Platforms provide data measurements on a per system and per slot (CPU) or virtual slot (VM) basis as described in the following figure and table provides an example for a file that includes such measurements. Note the separate lines containing data for system and for slot data measurements. The method we are using now is a surface plate setup in the quality lab, V blocks, snug fitting gage block stack in the slot, and indicated parallel with the plate using a height stand. Then the distance from top dead center and bottom dead center to the gage block stack is measured.Last update: 9/5/2016Those of you that have purchased or are considering picking up one of the recent Winchester Limited Series BPCR manufactured by Miroku have noted that many come without sights. The rear receiver tang is drilled and tapped for a sight and a female dovetail slot has been cut for installation of your preferred front sight. Most sight suppliers are familiar with the Browning BPCRs but may not understand that the more recent Winchester BPCRs are identical to the Browning’s including the dovetail slot dimensions.There are many sizes of dovetails. To get an idea of the various dovetail dimensions go to Brownells.com web site and search for dovetail cutters. In the following discussion I will limit my comments to dovetails on rifles, which is something I know a little about. In general there are three or four measurements that define the dimensions of a dovetail slot: the opening and end widths, shoulder angle and depth of cut. The width of a female dovetail slot is measured along the long axis of the barrel at the bottom of the slot, the widest fore and aft point of the dovetail. If the slot is tapered, the right opening, with the muzzle pointing forward, is slightly wider than the left end. The shoulders are angled inward and the slot is cut to a specific depth. If the slot is not tapered it was likely cut with a standard dovetail cutter. The two critical specifications of dovetail cutters are the width and the shoulder angle. The depth of cut is determined by the gunsmith or machinist. Therefore a 3/8” dovetail slot with 60° shoulders is 3/8” (0.375”) wide at the base and the angle from the base to the inside of each shoulder (or side) is 60°, which is by far the most common dovetail angle used in modern firearms.If you check with Browning or Winchester, they will likely inform you that the BPCR dovetail slot is 3/8” with 60 degree shoulders and is cut to a depth of 0.090”; all of which are accepted as an industry standard on modern firearms. But knowledgeable gunsmiths are aware that some factory barrel female dovetails slots are slightly oversized on one end and usually tapered to allow easier insertion of the male sight dovetail. In my book on the Browning BPCRs I measured several rifles and reported the range of dimensions. Nominally a 3/8” dovetail will measure 0.375”, but the right opening of the Miroku/Browning dovetails ranged from 0.380” to 0.384”. I recently checked the dovetails on several Miroku/Winchester BPCRs and confirmed approximately the same range. I also measured the left ends and found the width to range from 0.373” to 0.377”, confirming a slight taper. Therefore, be sure to follow the industry standard process of removing an existing sight by drifting it out from left to right and installing it from right to left. So how does one accurately measurethe dovetail width?If an existing front sight is being replaced the first thought may be, why not just measure the width of the base of the old sight with a conventional micrometer or caliper? The problem is that male sight dovetail bases are slightly rounded on the edges, if for no other reason than to remove the sharp edge for safe handling, resulting in a narrower dimension than the female dovetail slot. A recent example is a front sight I removed from a Browning BPCR. I found the right opening width was 0.385”, but the width of the male dovetail base of the sight was 0.376”. The next thought that may come to mind is to use the rear or inside measuring jaws of a caliper on the female slot. Due to the slight offset and edge thickness of the jaws, an accurate measurement is almost impossible. So what’s the answer? I’m no expert on dovetails, but there are four techniques that I’m aware of.If you expect to be cutting numerous dovetail slots and installing sights, one solution is to order a wire gauge dovetail measuring tool from Brownells. The current price of one made by XS Sight Systems (part # 006-101-000WB ) is $54.00 plus shipping. But the vast majority of shooters reading this article are not gunsmiths, and working with dovetails is not a common occurrence.Another method is to make a cast of the female dovetail slot using either Cerrosafe or epoxy. Once the cast is removed, measuring the width of the male dovetail cast is simple. I have not used this method but understand it works well as long as the Cerrosafe is removed at the proper time prior to enlarging and locking itself into the slot. If an epoxy cast is made, it should be relatively easy to remove as long as the dovetail is sufficiently coated with a release agent such as paste wax. By the way, never use a steel punch when removing and installing sights in dovetails. A brass punch will work but will likely leave a thin brass smudge on the sight surface. And always 1st check to determine if the sight utilizes a setscrew to lock it into place. I use a short section from a hard plastic Delrin rod and have yet to run into a sight that I could not remove or install.One quick technique that works that works for me is to utilize a slightly tapered gauge, cut with common scissors out of thin shim stock. The gauge width should taper from a dimension narrower than the slot to slightly wider than the slot. Sharpen the long edges of the gauge with a file or sandpaper. The gauge is pushed in by hand and ’wedged’ into the bottom of the female dovetail until it stops. Mark the gauge at the start of the dovetail, pull it out and “gently” measure the width at the mark with calipers or a standard micrometer. Carefully using this technique will result in an adequate measurement. And don’t forget to measure the opening and ending slot width, which will also provide the slot taper if any exists.The most accurate technique is to use a couple of precision steel pins of identical diameters, which are placed in the dovetail (refer to the figure below). The distance between the pins is measured with a caliper and used in the formulas below. Just ensure the diameters of the pins are small enough to contact the side of the dovetails below the top edge. A couple of 1/16” (0.0625’) drill shanks should work fine. Since the vast majority of dovetails have 60° shoulders, I’ve simplified the formula so you don’t have to figure out the cotangent of 30° (60°/2).Slot Width Measurement
*What is the ’standard’ method for dimensioning slots? We have for years located the slot by the geometric centerlines and described the slot size by note. For example: ’SLOT 9/16 X 1’. Some of us are wanting to locate the slot with the longitudinal centerline in one direction and by the ends of the slot in the opposite direction.
*In any high performance array, it is necessary to make careful measurements of single-slot admittance for a family of slot offsets and lengths. 36 shows the Stevenson resonant conductance, which is a function only of offset. Slot resonant length involves three variables: x/a, a/b, and β/k.
Register here: http://gg.gg/oj7gw
https://diarynote-jp.indered.space
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