This is a 100mm Dia. lens holder and extension arm for use with amongst other devices, e.g. a popular desktop soldering station sold on eBay.
(Copyright on the original workholder base in the photo belongs to its originator(s), not me, as I am merely adapting an existing device by producing a thing which enhances its functionality.)
I found it necessary to upgrade the existing work stand as the reach of the original arm was too short, thus making it difficult to get correct focus while also trying to use a hot air blower on the SMDs and board. There are pairs of 1mm holes prepared for inserting the wires of 3mm or 5mm LEDs (x12 off, wired in 4 sets of 3 on a 12VDC supply), which can then be used for illumination.
The lens holder CAD design itself is of 3 sections in Fusion360 format and the arm is customisable where several L&R section pairs can be added. The arm ends have supports (1mm pillars) already added and only need rotating /laying flat in Slic3r to then prepare the gcode file(s) at the desired resolution/ parameters for printing. Once printed, these supports can easily be removed with a thumbnail and smoothed over with a flat/half-round file. These extensions can also be used in many other applications.
The larger 100mm Dia was chosen for greater subject visibility and uses the lens from a simple glass-lensed magnifier, also found on eBay. (The related photo however, shows a lens holder with the original lens of 78mm Dia. for the first iteration.) The method of construction is very similar for other sizes. I would suggest however that acrylic lenses be avoided as their quality and scratchability is too often an issue. Glass gives a generally far higher quality image albeit a heavier device.
I feel this design makes for a much more slender and elegant result than the original somewhat 'chunky' and not-quite-colour-coordinated one.
The extension arm and lens holder used on their own, can also be adapted as an alternative sort of handheld magnifier without the smaller sections, with a neckstrap through the hole in the base, but it might be better to reshape the edges of the longer arm (in CAD) for use as a proper handle!
The Fusion360 files are therefore provided to enable customising to suit. The gcode files are provided if customising is not needed (or if you haven't access to Fusion360) and you just want to print it all out.
The Extension Arm build plate gcode is set to 0.10mm detail, fill density of 25% and estimated time to complete (in Slic3r) is 3h 30min or less.
The Lens Holder build plate is set to 0.10mm detail, fill density of 40% and its estimated build time (in Slic3r) to complete, is 4h 34min or less.
I would suggest editing the lensholder buildplate element selection in your respective slicing program(s) prior to printing, by creating relevant gcodes of just 2 of the elements as opposed to all 3 at once, because their brims print only just within the boundary of my own original Prusa i3 MK3. For those with smaller heat beds, this will be unavoidable.
As this my first foray on Thingiverse, I considered it appropriate (for a few reasons) to make this design freely available, hence the Creative Commons - Public Domain Dedication, along with the saying, "The first one is always free" :-)
However, as my dear late father (ex BSAP) always taught me with the phrase "Make yourself useful", here it is, dedicated also to his memory and whose life and intent I've found so inspirational.
UPDATE: Filletted (rounded) edge extension arms added 18/03/2019
- Both .STL and 0.07mm Detail gcode buildplates added.
I think this gives the arm a little more elegance and is more in keeping with the rounded nature of the related lens holder itself.
UPDATE: Extension arm build plate added (mid length) 21/03/2019 (.STL file)
UPDATE: 78mm Diameter Lens Holder build plate added 08/04/2019 (.STL and .Gcode files).
This diameter holder fits the original acrylic lens which comes with the desktop workstation which is shown in the image in the 'How I designed this' section below.
This latest iteration of the holder is however, a redesign with more room for the LED wiring which fits inside the top rounded ring around the lens.
White, to suit original workholder.
Use of brims is advisable as the printed items must be maintained flat in order to align properly when assembled.
If the PLA doesn't stick to the board properly then it can warp upwards from the bed during printing, especially where large-area footprints are involved.
I use 'Dimafix' by default and add brims when needed, on a Kapton tape covered heatbed.
Printing it all out together isn't such a good idea if you get a lot of 'gossamer-type' stringing. There is far less tidying up of 'loose ends' if things are printed separately!
Always dust off/ clean the heatbed before printing - This is like making sure a surface is grease-free before applying glue. The result of that little layer of unwanted 'stuff' getting in the way of adhesion is equally frustrating.
The gcode files are in ultradetail for quality's sake and yes it will probably take 5+ hours for the main lens ring, the thin lens-securing ring about 48min and the top cover about 2+ hours. Quality however, never goes out of style and you'll want to use quality tools if you're going use them all day every day, so it is a worthwhile trade-off in the long term.
Once printed and the remnants of any brims or stringing are neatly removed, the LEDs are inserted from below and wired up in 4x sets of 3 LEDs each, i.e. 3x LEDs in series (NB observe polarity!) per set, each set occupying one quarter of the circumference.
The wires for each set follow along inside the opposite sides of the hollow upper section, by placing the mounting lugs at the 6 O'Clock position, each set at the top has one single supply wire running to the 12 O'Clock position, powering the top 3 series-connected LEDs on the top left and right hand sides respectively.
The same method applies to the lower two quadrants, producing a symmetrical/ mirrored wiring arrangement, the two sets of Pos & Neg leads then being connected in parallel to a single twin-lead flex near the mounting lugs, carrying a 12VDC supply of roughly 270mA or less.
It is important to keep the LED wires short enough so as not to occupy too much of the void which will be covered by the rounded top ring, as doing so will make it very difficult to fit. Likewise fairly thin 1mm cross section multicore leads should be used to connect the LEDs for the same reason.
A pair of small holes is made (with a pin-viced 2mm drill but be careful!) in the side of the upper rounded top section, for the 12VDC leads to pass through to the 3mm eyebolt on the hinge of the mounting lug, down through P clip and then connected to a standard inline or chassis-mounted DC power socket connector.
With the main lens-holder section laid flat, place the 100mm lens in the middle, place a few drops of clear non-resinous glue which will remain flexible after curing (it can be removed more easily later if necessary so no superglue!), around the edges of the lens to secure it in place.
Next, if the thickness of the lens's edges allow, place the thin ring inside the main lens holder ring & on top of the lens to stop the lens shifting (the glue should do this anyway so the thinner ring may not be needed). Thread the 12VDC leads through the two small holes made in the rounded top ring.
Lastly, place a thin bead of the same glue under and/or around the outer edge of the rounded top ring, which then goes over the LED leads and wires already connected up and soldered into place.
I decided not to try and 'tunnel' the power leads through the new extension arm sections because the very thin leads on the original arm were getting pinched and damaged when the arm had to be rotated either fully forwards or backwards. (The LEDs stopped working.) There was no provision in the original unit to avoid this problem so the simplest method was to secure the leads down along the outside with P clips, which proves more reliable.
The extension arms are mirriored, so that they 'mate' when placed together facing each other and interface, with 3mm screws, washers and preferably nylock nuts, keeping them secured. It is also a good idea to use thumbscrews for the more frequently adjusted elbow joints. (I used a 30mm M3 screw and M3 eyenut for retaining the 12VDC leads on the lens's lugmount.) For those who like the flair of eyebolts, try using paired M3 eyenuts and eyebolts - they can also be very useful if thumbscrews aren't available. :-)
The base of the new extension arm is then attached to the original workmount with the mount's original 3mm thumbscrew and nut.
And there you have it!
In-situ 5mm LED layout.
Wiring up the 3V, 5mm LEDS - 4sets x 3 LEDs per set = 12VDC power supply.
Insert the LED leads through the holes from under the main frame, noting carefully the symmetry of the alternating +&- LED (long & short respectively) leads down each half of the circle - this is crucial for LED polarity!
This method thus requires one POS (red) 12VDC lead to 12 O'Clock position at the top, which then supplies both top quarters of the LEDs and their respective NEG (black) leads following to the base of the device. The two lower quaters are similarly supplied by a further two pair of leads, all of which then being gathered to produce four sets of LED triplets running electrically in parallel.
The 12x LEDs which are subdivided into two sets each, producing four sets of three LEDs per set. Unfortunately the two LEDs nearest the mounting lug were bypassed to provide enough forward voltage to produce enough light off a 12 volt power source. This arrangement will be modified in CAD at a later date to produce an evenly distributed number of 12x pairs of LED holes around the circumference.
A 12V supply was chosen as it is more readily available, thus making the project a little cheaper and less demanding on R&D time.
Current drain measured at about 270mA max. It is a good idea to also check LED colour temperature so they all match when fully lit together. Easiest way is to buy a set of 100x and see how each looks alongside the next as they can differ slightly.
Mounted 5mm LEDs with soldering completed & under test.
Many a satisfying hour spent over the lens!
Design tools, motivation & method.
Desktop PC with 16Gb RAM, quad-core processor, Win 8.1 and Fusion360 (educational license).
Proper planning is essential!
Measuring the overall extra length required vs the original arm which measured only about 50mm, meant there is significant room for adaptation and improvement on what is nonetheless an already excellent starting point for a workholder design.
This project enables an extension of about 150mm reach, plenty for the 3-5x focal length of the magnifier lens and also enables handling of varying sized/ awkwardly shaped objects, so it's not just for increased flexibility when soldering minute SMD components on PCBs.
This extension will come in quite useful for those who wear glasses (yes, I do too!) as the focal length can be adjusted to suit, especially for the longsighted among us.
If an acrylic lens is used, be aware that if buying cheap, you'll likely get what you pay for and remember: acrylic lenses scratch easily, especially if used in a robust manner or environment.
Clearly one doesn't need to use the work holder as shown in the photo and it may prove more useful to find an alternative base depending on specific needs.
100mm Magnifying Lens Holder, separate elements in CAD (Fusion360)
100mm Magnifying Lens Holder assembled in CAD (Fusion360)
As we often find the need to adapt ourselves and our methods if we're to do a better job, it is constant innovation that drives industry and technology forward - we find ourselves building on the shoulders of giants!