Tidying up the SMT collector design

Brilliant, should have thought of this in the first place, but there are belt length calculators out there. So, I lucked in (I think) to a standard 188mm belt assuming the 70tooth is about 47mm diameter and the 20tooth is around 15mm.

Otherwise, I redid the side panel for the side with the motor. I did a cut-out for the sliding motor and mirrored the piece so you can opt to having motor on the outside on either side as per your preference.

I thought to, if I had to fiddle with the motor slot location, a tool to cut-out the motor from a panel would make sense. So all three elements (two mirrored sides and a motor cut-out) at Figure 1.

Figure 1

Eh? Yes, it makes sense then to have one side and a cutter and one can then have what ever length belt. I added a means to cut-out the sliding motor slot. The final design will have two cutters, one with heads and one without, so one has options. Just import a side and one of the cutters into FreeCAD, use the belt calculator to set the distance between the centre of the 15mm hole (which will take the nylon LM8SUU), and the centre of the oval land in the middle of the cutter.

Figure 2

So, yes. That makes sense. Have found a great video tutorial on datum planes and sketches. I might also redo the cut-outs using those aspects of FreeCAD. Not to mention, placing the cut via calculating the distance between pulleys, given the length of the belt and the diameters of the two pulleys a la the formula (Figure 3 from the website):

Figure 3

So, a spreadsheet or a python function.

Heat set adaptor for drill press

Figure 1

Multiple ideas for DIY heat set presses. Closest thing to my needs makes an adaptor for a drill press.

As I have a drill press from Jaycar, thanks to an XMAS gift card, I only need make an adaptor for that to hold one of my soldering irons.

There were problems with the drill press option I found. It didn’t fit my soldering iron and didn’t make sense in terms of needing a compliant mechanism to respond to tightening of the ring holding the insert.

So Figure 1 is a cube, with chamfers, polar rotated, and then welded to a hollowed cylinder and a notch cut out to turn it into a compliant mechanism.

Figure 2

Figure 3

RE Figures 2 and 3, ready for work! I have a M3 heat set tip bought locally, as a full set I had ordered got returned to vendor in US, when USPS cancelled shipping to Australia. I have again ordered a full set of tips, hopefully they’ll get through this time.

I had to hand set a pesky M2 heat set in my prototype SMT cover tape collection spool (Figure 4). Not a bad job. Ignore the metal LM8UU, as I have a batch of nylon one’s still coming – since I need to trim them to fit the 8mm version especially. This one is knocked up to trial the break setting. It will otherwise have a M2 grub screw in the final versions.

Figure 4

In the end, I needed second pass over the design. Firstly, the soldering iron has a rubber sleeve for user comfort. It comes off, and it may well need to, so as to allow a tighter grip on the iron. I will likely build a power supply for my 5 pin irons (that turned up in error), as the one in the photo is my spare 7 pin iron. The other tuning would be to make it longer than the 10mm currently.

Figure 5

So, Figure 5 show’s a snug fit, after the re-design. The CAD tool is handy. The sides of the handle are not parallel, so a cone worked a treat as the binary cut. All dimensions spot on. Snug on soldering iron handle. Slipped into press. A few turns of the hex screw of the press and we’ve a good tight fit.

Figure 6 then is the final model. You can’t see the cone (there was 0.3mm diameter in it but worth it). Now 21mm high. So, there is no movement now when mounted. When leaving the rubber grip in place, the thang wobbled, obviously because the rubber allowed for movement.

Figure 6

SMT cover tape collection

So, while still waiting on a few things to finish builds, I decided to go for broke and really stack up projects, to make sure nothing ever gets done … ROTFLMAO!

Figures 1 and 2 are the ends for the SMT tape collector. To get there I hacked a prototype in FreeCAD suing Parts Design adding with sketches and a few other tools. I looked at the problem of 3D printing these – not the least of which was having the Bear Build complete OR going through the hassle of having the makerspace printer for 12 hours (when everyone else is lined up to print Pikachus).

So, why not do my first laser cut project in 9mm MDF?!

A little frustrating since with grouping of parts, using sketches etc., when exporting to dwf all manner of crap was included. So, after modelling in 3D to sort out a range issues, I then went back to Draft add-in and started from scratch, lifting dimensions off the 3D prototype model.

The design is to take 5×10.10mm aluminium tubes for the frame members that, in places, the cover tape will slip over. Three is a 15mm diameter hole to take an LM8UU bearing. The LM8UU will allow the rotating 8mm linear rod that will have the “skidding” collections spools.

Per Figure 3 and 4, the mini-reels (100mm dia with 50mm dia hub) will run on 3 of the aluminium rails.

I am trying to print a 70 tooth GT2 pulley at the moment. My Finder is playing up at the moment, I have had to unblock the Microswiss hot-end, BUT now I forever cannot get the sticking PLA to stick to the new bed sticker, so I have to go up the road to get some sticky glue.

Figure 6 is the NEMA 14 I thought would suffice to drive the thing. Yes that is an LM8UU linear bearing sitting next to the stepper!

Makerspace is closed this weekend as they are off at a community science thang, so next weekend I’ll grab me some 9mm MDF board and have that first real go at a laser cut.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

What? Oh yeah, some tensioning of the pully belt for the collecting spools might be apt, so update is a Figure 7. To achieve this, given we’re using a laser, is just have some overlapping circles and rectangles.

Figure 7

So, whether I can retrofit such a SMT cover tape collector to my corexy PnP design is, yes, a question (Figure 8). One trick is to use the mini reels (100mm) and, since I would have to load them myself, invert the tap, to run it over an 8mm linear rod embedded in one of the stands. As a start mind you, very crammed that end when the x-gantry goes back there.

Figure 8

But, of course, it may make more sense just adding SMT cover tape collectors when using tape reels per Figure 9.

Figure 9

What? Yes, I do have to update the 3D model of the SMT cover tape collectors from the new and improved 2D work. You are a hard audience!

Prototyping a SMT cover tape “collector”

So, I kept seeing a style of SMT cover tape collector (see blue and white spools on the left in Figure 1).

Figure 1

It bugged me that there is no real name for that style of setup, or at least anything you can search on to find info on how they work – so as to allow a diy copy.

Then I lucked into a photo off the Net at Figure 2.

Figure 2

So, it seems they use a slip brake, which makes sense. That uses the grub screw against the shaft so that it grabs enough to pull loose cover tape onto the spool, but slips if it’s under tension. So a M2 heat set for that solves one problem (Figure 3).

Figure 3

I also opted to not fiddle and use nylon LM8SUU or LM8UU, inserted to leave the grip/slip to the adjustment of the grub screw (Figure 4). That is, not have to struggle with tuning the prints to fit snug but loose on the 8mm linear shaft.

Figure 4

I have a pulley and NEMA 14 on the way. I just have to do a little more modelling to design the supports. I may opt to build this for mini 100mm reels. Draft spools at Thingiverse.

Still playing with the design as in Figure 5. There will be 8mm, 12mm, 16mm and 24mm variants of course (12mm variant in Figure 5).

Figure 5

I will probably opt for a C-clip to hold the tail of the SMT cover tap onto the spool, to save fiddling with have to stick it to the spool.

A bit of fiddling and voila!

No Pins (just a package)

Dual Inline Packages

QUAD (pins all the way around)

The way I do this is set the length to 80mm (of the 2080 variety), divide by pocket Y dimension and use the ceiling to get the actual row count (so the width may be slightly wider than 80mm but by a proportion of a single pocket). I then centre the bisector of the screw holes so they are always centred on whatever the length becomes and they are also always 60mm apart to mount in the outer slots of the 2080 extrusion on the bed of the manual PnP.

Scheisser!

I need also define a bucket! Give me a moment … okay. So, I made buckets Shallow or Deep and I also added an option to add a mount at the other end.

BUCKET

What? The atmega328p has a 6.9mm package? Say what? You want WHAT? Embossed labelling?! You are one HARD audience!

Mitt embossed label

And before you ask

Blah, blah, blah, blah, blah, … so I also then added a test piece build.

Test piece generation to do quick print checks of bucket sizes

Happy little vegemite, snug as a bug!

Funny how it happens

So I found the OpenSCAD files for a neat parameterised SMD tray.

minitrays

But it was designed to size by package row and column count. It has magnets at the end so they clip together for stacking and you can use a sheet steel bed on you PnP and they’ll sit fine.

For the manual PnP though, they are a pain since tuning them to the 2080 bed was fiddly and, of course, magnets and aluminium are not friends.

So, of course, despite there being a solution I hacked the code to define the tray by tray dimensions wanted, as well as added holes based on M3, M4 and M5 screws. The screw hole location is with reference to the tray length so that allows me to tune for seating on the 2080 extrusion beds of the manual PnP.

Figure 1

Mind you, modifying the code was a headfuk as the code was not really functional in the coding style, poorly commented etc.

While the honeycomb seems to make sense then for cleverly stackable trays, for not when in use on the PnP bed, then end result is dropping a few unnecessary features.

I did come across another tray design, but no source code, at Figure 2.

Figure 2

This was an epiphany, since it was way more straight forward. So I coded up a test piece and played with it. Noting that pins are either all the way around or only down a pair of opposite sides I ended up with a prototype (Figures 3 and Figure 4).

Figure 3

Figure 4

So I thought about it and then set the defaults in Figure 5 to the Atmega328 in Figure 2.

Figure 5

So with a little fiddling I get to Figure 6. So, a little brittle, since the rows now need be greater than 70mm in size to ensure the mounting has the 60mm spacing to span the slots on the 2080. I might auto calculate rows to fit and then just adjust columns. I am not banking on stupid numbers of cells and a single row could easily do. It also occurred that I also need to code for no pins and just package dimensions. Scheisser!

Figure 6

3D printed parametric SMT feeder

I am working on batches of pushpull feeders for my manual pick and place machine.

So while waiting on the last few parts to turn up, I have been doing a production run of feeders for the machine, Figure 1.

So a DA VINCI AWARD needs to go to Mark Maker (stage name I assume LOL). Noting I am also using SMT trays to tuned to fit onto the working beds provided by the 2080 extrusions.

DA VINCI AWARD FOR CLEVER DESIGN

3D printed parametric feeder tray

The feeder tray for small strips I am using is this one, so thankyou Michael G.

Results in a SMT feeder tray with the profile in Figure 1.

Figure 1

Its in OpenSCAD and fully tuneable as in Figure 2.

Figure 2

I have tuned the script to fix something that bugged me. The original script included both screws and magnets to hold the tray down. Likely the idea of printing one gadget then choosing mounting means on the day. I opted to either print with screws OR with magnets. I also found the screw option a little over the top, as it put screws into every feeder slot. So I modified the script to optionally only add screws in the end feeders – yes if you are really worried about the tray blowing off in a hurricane, the option to stuff a screw into every feeder is still there. I also uncommented the middle screw code and made it optional – so it will really REALLY stay put in a hurricane AND a tsunami! I also parameterised the screw position from the ends. See the editor modes in Figure 3. You flip between screws and magnetics by toggling the screws option on or off.

Figure 3

In the screw menu you’ll notice a screwDia(meter)?! That is now for setting the mounting screws to M3, M4 or M5. I have set the recesses for button heads only, so use hex heads at your peril (just needs ensuring the tape height clears – yes that is a parameter!) I also modified the script to provide access for screws when the tape is set to 8mm, as in Figure 4. I may also play with adding options using countersunk heads, I am fiddling with that now.

Figure 4

So, for your viewing pleasure, an example then of screws in outer feeders OR magnetics is at Figure 5. All of this trouble to allow these trays to be tuned to my manual PnP machine build.

Figure 5 – Screws (top tray) or magnets (bottom tray)

But hats off to Michael G for his design for the magnet inserts at Figure 6!

Figure 6

Brilliant! Took me a little while to work this out. What on earth was the inner deposit doing? What is a coding artefact? My first thought was the outer wall was set by the magnet diameter, but …

… it then dawned on me this was a clever press-fit design, with the inner wall set to the magnet diameter! Clever, since you want a positive purchase but also flex to allow for fitting the magnet. To wit, it provides a very positive and pleasing clicking in the magnet – which requires a little but not excessive force. Keep this idea to the side people, you might find it useful in other designs.

So, this blog’s DA VINCI AWARD today goes to Michael G! Congrats!

DA VINCI AWARD FOR CLEVER DESIGN

The end result is in Figure 7. The parameterisation of the holes a must, as I had space for a 100mm tray, with holes 60mm apart, to ride atop the 2080 extrusion beds. I am assuming that I’ll get more use out of this arrangement than the push pull feeders as I am buying samples of SMT and not reels at the moment, since I am only making “batches” of up to 5 or 10 boards. The approach being design or use an open source design, get a batch of boards from pcbway, keep one assembled item and sell the rest on ebay (hopefully) to self-fund the projects.

Figure 7

What a great little piece of machined heavon!

Look what is here!

Can you picture it?

So, along with the Z-Axis for my corexy PnP project, all the LM8LUU and the single LM10UU required turned up.

The LM10UU was a duff, since that is used in the full VORON Legacy build, and so won’t be needed per se. Though I do have 10mm linear shaft floating around, so it won’t go to waste.

I note that the Nema8 Hollow Shaft Stepper has turned up in country, so I think I will have all the bits I really need to do a full build.

Though, I have 3 builds piled up at the moment, so everything is stashed away now, waiting its turn.

In the meantime, I will need do some more work on the X-Carriage design in the background.

In the meantime, quick measurements with my callipers suggest I was wise not to crash ahead with the final design of the X-Carriage, since the vendors DO MEAN +-3mm in their measurements (and that’s even for vendors selling callipers LOL).

Slight adjustment

Notice the difference?

Just playing with minor mods to the uStepper 4 model to get around a really irritating design decision by the original author. That is using 15mm diameter aluminium tubing. Since, I am finding multiple places aluminium tubing jumps from 14mm to 16mm! Same pattern in carbon fibre tubing.

So, just fiddling with hacking this part from 15mm to 16mm fitting. Using the Manipulator add-in to great effect to reverse engineer centre point of cut, based upon the radius of the cut. Then using the centre provided to site the new cylinder to cut a new chunk out. The trick is that as the rod is thicker, it also had to be lifted a tad (0.5mm) away from the teeth of the belt drive. So a similar fiddle in the bracket.

I’ll do a test print at some stage, before moving onto some of the other parts. In fact, the bracket is on the printer right now, burning through that horrible green colour I opted into out of an urge to homage.

UPDATE

So, turned out not bad in draft print.

Draft print for 16mm shaft

I need to grab some 16mm shaft to try this. I did find 15mm carbon fibre on Aliexpress but don’t really want to wait. But, with the bank up of project, I guess I could.

While the green filament is loaded, I am knocking up a few 8mm feeders for my PnP as well.