CAD – Zitt's Blog

February 21, 2020February 22, 2020

F-150 Trailer Hitch and Custom Case

Back in October 2018; I purchased a new 2018 F-150 Raptor from new dealer stock to replace my 2000 Dodge Dakota which I purchased new from a dealer in Oregon. Given the way Chrysler failed to support their products under warranty; I informed them that I would never own another Chrysler product again. If you want more details as to why I won’t support that company any more; I posted briefly about it here.

I bought the Raptor to replace my daily driver and to haul the occasional Pinball machine to/from events. One of it’s jobs is to haul my enclosed trailer when I’m taking more than one machine. The result is I needed a new drop hitch. I originally started with a 8inch drop; but that was really too low for other trailers – while it fit my trailer fine. I ran into this when a friend rented a Uhaul trailer and it was nearly dragging the ground. As a result I decided I needed an adjustable trailer hitch which then became obvious that I needed a way to store this trailer hitch when it isn’t in use. On my other truck; I basically left the hitch always on the truck and managed to hit it with my shins or sometimes the driveway on the way out of the house. I wanted to avoid that this time around. Originally; I thought I might fit the hitch in the center console; but it turned out to be too heavy and bulky. So I’ll also be talking about my storage solutions in this post.

Final Amazon Shopping List:

My saga began when I came across a Uriah Products UT623410 Adjustable Aluminum Mount with 3 Interchangeable Balls-6″ Drop on a Amazon Warehouse deal for a good price. In the past I had really good experience with AMW deals; where the packaging or minor issues which didn’t effect functionality were worth the discounted amount. The biggest problem with this mount was it was what I’d call heavily used. It appears the previous purchaser used it for a cross country trip; then boxed it back up and shipped it back to Amazon. Because of this I decided I wanted to clean it up and make it match the “Electric Blue” of my Raptor. I started with the drop mechanism. The two main pieces are made from a thick Aluminum alloy; so they tend to scratch and dent under heavy use. Specifically; the drop mech tends to “crease” on the lower part of the receiver when it’s rocking back and forth while hauling the trailer. I cleaned up the previous user’s creases with a file and some sandpaper:

I proceeded to clean the part and then powder coat it with the blue powdercoat I had from a previous project.

I did the same thing with the slidable ball mount; here’s the part getting the powdercoat:

I used some carriage bolts sourced from Lowes to secure this heavy part on my makeshift powder coating rack.

Next, I used a scrap sheet of aluminum to make a makeshift “cooking” stand for use in the toasting oven. Here’s the part before heating:

Here’s the part after curing the powder coat:

I did some more offline work to add a powder coated “raptor” to the ball mount on both sides. Sadly I didn’t take any pictures of this process. The process was that I basically put some Polyamide tape over the mount and then laser etched the raptor image into the powdercoat and tape. Once I had clean metal from the laser etch; I powdercoat a matte black onto the polyamide tape and re-baked the piece. Here’s the installed ball mount with the Raptor embellishment:

With the ball mount complete; I turned my focus on how to store the hitch when it’s not in use. This turned out to be tricky because I had already used up all the under rear seat storage with other items; so I needed a organized way to keep it out of the way while being able to quickly install it when needed. After some research; I decided I needed to use a Pelican Vault V200 Medium Case to store the hitch and all it’s accessories in “layers” inside the Pelican. I wasn’t keen on hand carving foam… and the foam that came with the Pelican wasn’t strong enough to resist the weight of the hitch. A plan solidified which involved laser cutting some high density PE foam on my cutter. Why PE? Because it’s laser safe ad can be bought readily on Amazon. Before I got to that point; I proceeded to work out the geometry in CAD before committing to lasering the foam and to make sure everything would fit.

I started by using a set of digital calipers to measure the various parts I wanted to put in the case and transferring the basic outline into a DXF file. Most of the parts are under 2inches tall. with the notable exception of the ball mount. This is why I decided on the 2inch thick foam and then stack two layers of the foam to hold the various other miscellaneous pieces. For the Ball mount; I’d have to mount it vertically to keep the horizontal space for the “L” shape of the drop. A couple of design itterations later; here’s the final bottom layer as seen in CAD:

The bottom bascially holds the three balls, the ball mount, the drop, one of the locks, and one of the ball pegs. The Top Layer housed the remaining parts:

This layer houses the remaining parts:

remaining Z-height of the Ball mount,
The remaining Z-height of the 2-3/4 ball,
The remaining ball peg,
a second hitch lock,
The unused receiver hitch peg,
a tonge lock,
a spot for the Plano Case – which holds the misc clips,
and a spot for the Keysmart keyring (for the various keys)

I wanted the bottom of the locks and pegs to be flush with the top of the given layer so I made some “filler” parts out of 1inch. I wanted the ball mount to be “snug” between the first and second layers; so I also made a filler out of 1/2inch foam to mount on top of the second layer.

With the CAD work done; I started trying to laser cut this PE foam. Turned out to be quite tricky for several reasons. First; there’s no published power/speed values for the foam. Second; my poor Epilog 24TT laser just lacks the power to punch thru the foam. My laser specs for a new tube is 25watts – but I’m sure mine has aged and probably puts out 20ish watts if that. Third; the 2inch foam is really too thick for the 2in lense my machine has. Focusing on top of the 2in foam; the laser’s focal distance causes almost unmanageable beam spread at about 1/2inch from the bottom of the 2in foam. This causes extreme melting at the “bottom” of the layer. Again because the focal length of a 2in lens; it was impossible to re-focus the laser to cut the final inch in z-depth on the foam. Regardless; I was able to cut the pieces – which really turned out better than if I’d tried to hand cut them. I don’t remember specifically what I used for power; but it was multiple (read 4-6) passes with varying power. I started with 30% power at 30% speed for the initial cut. This was dialed in by doing some test cuts to maximize cutting and minimizing shrinkage due to excessive heat at the cut line. With each pass; I reduced the speed by 10, 5, and 5 while adding 20% more power. Again; this was to “punch” thru the remaining material without being able to refocus the 2in focal length. Here’s the final “table” of the power settings used for each pass:

The 1 inch and 0.5 inch foam cut much easier; I think the 1inch foam cut in 2 passes and the 0.5inch with one pass at 30/30. With the foam cut; it had to put the parts together. The only way to really get this foam to glue to itself is using CyanoAcrylate glue. I forget where I read this; but Google search basically indicated this is how the “industry” makes custom shipping foam out of this stuff. I did this by putting the CyanoAcrylate Accelerator in the Needle tip Glue Bottle. Then I put the Accelerator on one side of a seem and the CA glue on the other. Then using my fingers; pressing the seem together for about 15-20seconds. Take my advice here… unless you want to be dealing with superglued spots on your finger tips; use some disposable latex gloves. The CA glue still gets everywhere… so make sure you’re wearing “junk” clothes. Even after 20seconds; the glue really hasn’t set well. So once you completely finish a “layer”; leave it to set overnight so the CA glue will completely “cure”. The Accelerator is suppose to make this bonding instant… but either I was using too much of it… or the glue had a longer shelf life. So since I was going to be using this foam for really heavy things; I just left it to cure overnight.

What did all of this work yield? Here’s the bottom layer populated with it’s various pieces:

Here’s the top layer with it’s pieces. This was a earlier non-reworked version which didn’t have the tounge lock or keysmart keyring areas in the empty spaces.

The Plano Pocket Box holds the various clips, o-rings, and extra keys for the locks:

IIRC, I reused the compressible foam sent with the vault case for the top of the lid so that the layers would remain snughly compressed in the Vault case:

I used the Premium Cinch Strap to secure the case in the bed of my truck by securing it to the Camper shell’s linear actuator:

With that project is complete. I’ve used the case about 3-4 times and it makes the whole storing of the drop hitch easy.

July 27, 2019July 28, 2019

Wear Prevention: Outlane Mylar Protection

Honestly; I’ve been neglecting my Stern Star Trek Pinball machine. I got it new-in-box and didn’t do anything to protect the outlane hole which feeds the ball trough. My machine has seen some play at various conventions like Texas Pinball Festival since I purchased it back in 2016. The issue is that the steel balls tend to wreck havoc with the clearcoat and wood under the clear coat. I helped mitigate this problem shortly after unboxing by installing a set of Cliffy protectors. At the time; Cliffy did not offer an outhole protector so my ball return hole did get any love. A couple of weeks ago; I looked and noticed some wear on my outhole. 🙁

You can see definite wear on the front and left side edges. It’s not massive; but enough to warrant some protection. I debated getting a new Cliffy outlane protector; but it only protects the front side from wear. As a result; I decided to try my hand at designing my own protector which would be cut out of 2mil adhesive Mylar (polyethylene) using my new Vinyl cutter.

I began by tracing the area with tracing paper so I could get the basic layout easily into the computer. I didn’t have a lot of room to work with so I decided to bring the mylar up to the black keyline just above the out hole. This would give me a little extra grip and make it easy to hide within the art work. I also decided I would wrap the mylar around the outlane hole pinching it between the ball trough and the underside of the Playfield. Finally; I would protect all three sides of the outhole to the metal ball guide seen the foreground. Finally; I decided to protect the outside corners of the PF in a similar way to protect the edges leaving cutouts for the legs of the metal ball guides so they wouldn’t “wrinkle” when the guides were re-installed. This was my initial design – and remains the my property (read: copy protected):

Copyright 2019 - Outhole — Stern Star Trek Outhole – Mylar

My design choices were to add the round corners created by the endmill when the Playfield was created and then add rounded Vs on the lines were the mylar would roll onto another perpendicular surface. This should aid in preventing wrinkles from forming at those junction points.

With the design created; there wasn’t anything else to do but cut it on the vinyl cutter and install it. It’s going to be very hard to photograph this crystal clear mylar but hopefully you can see it if you click on the pictures to get a higher rez image. Here’s the top surface with the mylar installed:

You can barely make out the outline of the mylar along the black keyline as designed. Additionally you can see the mylar where it wraps around the outhole sides and the two sides of the PF. Hear’s a close-up of the mylar wrapping around the PF:

Finally; the underside of the pf; where the mylar wraps around to be pinched by the ball trough:

I reinstalled the ball trough, all the ball guides, and put it back together. No issues what-so-ever with the installation and the mylar has no noticeable impact to the ball. Additionally; this should help minimize any additional damage to the clearcoat near the outhole.

If you are interested in a protector for yourself; I’m offering them forsale at my webshop: Stern Outhole protector – Mylar

August 31, 2018September 1, 2018

Pin2k CPU Fan Replacement

When I first got my Revenge From Mars from a local Pinhead; the fan was clogged with dust and grime. At the time; I simply cleaned the fan, removed the sticker, and added some oil to the bearings. This lasted about 3months before the fan began to make some horrible noises because the bearings were shot. I “lived with it”; but it remained on my todo list.

For years; I had watched threads about Pin2k in Pinside… always feeling a little guilty I had not eliminated the risk that my CPU fan would die… overheat the cpu… and put my RFM in jeopardy of force converting to NuCore or Pinbox. Today was the day I vowed to resolve that noisy fan.

First; I did not want to buy NOS (new old stock) of some 50mm fan made back in 2000 or some china knockoff that wouldn’t last another 18 years. I wanted a high quality fan with very little noise; but a good performer. I’ve grown to like the Noctura brand of fans because they aren’t cookie cut china knock offs. Noctura does not sell a drop-in-replacement for 50mm fans. Going smaller usually means less air flow with a higher “whine” because the fan blades have to go much faster to move more air. So I decided that I was going to try and use the NF-A6x25 FLX 60mm fan:

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and build an adapter to fit the larger fan over the existing heatsink. This blog entry documents my solution, provides a TAPR/NCLed DXF for my adapter, and links to a Shapeways implementation of my adapter my fellow pinball enthusiasts to use.

First, I removed the CPU box from my RFM and pulled out the existing CPU heatsink:

Once I had the CPU heatsink free; I unscrewed the old FAN from the heatsink. This was done for two reasons;

I need the heatsink to take caliper measurements in order design a 60mm to 50mm bracket.
Eventually; I’d toss the worthless 50mm fan – but wanted to keep it incase I couldn’t find a working solution.

Obviously; the 60mm fan wouldn’t fit within the 50mm cavity of the heatsink; so I knew I wanted to use some 1/4inch clear Acrylic as an “adapter”. I went into qCAD resulting in a DXF file which I could then send to my laser cutter. I wanted to reuse the 50mm fan/heatsink screws and the 4 qty Vibration-Compensators provided in the Noctura kit. My second proto resulted in success and looked like this:

Reusing the 4 qty 50mm countersunk heatsink screws; I attached the clear acrylic bracket to the top of the heatsink. Then I put the 4 qty Vibration-Compensators provided in the Noctura kit thru the acrylic bracket and into the NF-A6x25 fan. The whole assembly fit together quiet nicely.

I carefully; reinstalled the fan-sink combo back onto the cpu and socket. This was a little tricky because the 60mm fan is bigger; but as you can see the whole contraption fits well:

Conveniently; my Pinball 2000 motherboard had a FAN header right next to the cpu socket; so I simply attached the CPU fan’s 3pin PWM connector to that unused mobo connection:

I powered up the Pin2k system on my bench with both the original and the new fan connected. !That old fan really needed to be replaced! This new fan is ultra quiet; I don’t think you can hear the fan over the PSU fan even when the box is open. You won’t be able to hear the fan at all when its in the backbox behind the backglass. Success!

I’ve decided release this design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms; a DXF Drawing is posted here under TAPR/NCL license:
60mm to 50mm Fan Adapter Package

If you don’t have access to a laser cutter; you can 3D print this adapter from Shapeways:

February 15, 2015February 27, 2015

Stern Star Trek: Warp Ramp LED Mod

One of the items that somewhat bugged me about my new Stern Star Trek LE Pinball machine, was the LED in the warp ramp popup insignia. Specifically; I always thought the two SMD red LED didn’t quite fit where it was placed in the machine.

Photo Credit: Kawydud@Pinside — Original LED in Popup. *Photo Credit:* **Kawydud**@Pinside

The plan was to “replace” the LED round lens with a laser cut lense which duplicated the artwork on the insignia’s plastic. To this I disassembled the plastic by removing the four screws… and took the plastic to my HP scanner where I scanned the art into my computer. Then using Corel Draw, I traced the Red Arrow from the plastic art:

Portions (c)2013 Stern Pinball — Scanned Plastic with New Arrow Art

I recreated the arrow using red; then added the black border around the plastic to block light and give a round area to mount the new LED. Once I had the recreated arrow; I broke it into two laser cut pieces. One would be cut out of the matte/diffused Red acrylic which was used on the Stern Star Trek Pop Undercaps. The second would be cut out of 1/8″ opaque black acrylic – this piece serving as an outline for the red piece and support from the LED.

I took these files to Techshop.ws where I laser cut several of each piece for experimentation later at home. Once the laser cutting was complete; I used the black cad files to laser etch some 1/4″ plywood to act as an assembling aid/surface. When I got home; I used the plywood and some wooden toothpicks to clamp the two pieces together:

Acrylic Clamping — Acrylic Pieces Clamped for Bonding

With the pieces together; I used some acrylic bonding solvent to glue the two pieces together. I let the acrylic bond overnight.

The next afternoon; My Comet Pinball Red LEDs had not come in the mail – so I decided to go ahead and use the original LED for experimentation. I cut the round lens off the original LED using a new XACTO knife and then using some two part 5minute epoxy; I glued the lamp to the new lense:

LED Clamping — LED Clamped to new LENS w/ 5minute Epoxy

I allowed the epoxy to cure for about an hour. I then reinstalled the plastics and the new LED assembly:

I’m really quite happy with the way this turned out. It defiantly spruces up the warp assembly.

August 27, 2014March 8, 2015

Stern Star Trek: Vengeance Nacelle Mod

I really enjoy my Stern Star Trek LE Pinball machine… But one of the things which has bothered me on the machine was the way the USS Vengeance shines it’s bright blue Nacelle LEDs right in the eye of the player.

This simple mod aims to correct that. I knew I wanted laser cut some blue acrylic pieces to help defuse the LEDs; so I consulted google images to give me some ideas what the Nacelles were suppose to look like:

Without redesigning the whole Stern Nacelle; I decided a piece set about 1/4″in into the nacelle would be closer to film accurate. Also; in a couple of the google images; the Bussard collector looked more cylinder shaped; so I figured a deep etch in the back side of the plastic would be ideal. Here’s what my first prototype looked like in CorelDraw:

USS Vengeance Nacelle Prototype Peices

I then proceeded to Techshop.ws and laser etched/cut these pieces out on some 1/8″ Blue acrylic.

To remove the Nacelle; simply remove the top two philps screws holding the Nacelle to the ship assembly. Then remove it… On my ship; Stern was rather liberal with the hot glue; so I had to work the nacelle off by pulling the sides of the nacelle from the hot glue. The Blue LED is attached to the ship assembly; so you shouldn’t have to worry about it coming loose.

When I got home; I used some plastic epoxy to glue the piece into the left nacelle. This piece is to be position just past the flat ridge in the nacelle:

Here’s the Bussard collector installed with a little epoxy:

USS Vengeance Broussard collector — USS Vengeance Bussard collector

NOTE: the curved etch faces the rear of the Nacelle (etch toward LED)

In my case I found it a little easier to bevel the sides of the pieces with a file so the sides of the plastic pieces would make better contact with the sides of the warp nacelles. I put some epoxy on the sides of the piece and on the little round nub at the top of the nacelle so the piece can’t be shaken loose during the Vengeance battles.

So; How’d it turn out? I only modded the left side (right in the picture) and took this picture:

A close-up Before and After:

Want to do this yourself? Have access to Acrylic and a Laser Cutter? Great; I’ve decided release this design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms a PDF is posted here under TAPR/NCL license: Vengeance Nacelle Mod Package

Don’t have access to a laser cutter? Visit our store to get an inexpensive set:
http://pinball-mods.com/oscom/product_info.php/products_id/33

April 12, 2014August 14, 2016

EagleCAD Tutorial: Custom shaped PCBs

As seen in the Worklogs for the Star Trek: Mirror Universe Pinball project; Making custom shaped PCBs in EagleCad isn’t all that difficult. With a CAD file; one can make some pretty unique shapes to fit the project you’re working on. This tutorial aims to show just how easy it to create the perfect shaped PCB. The Author used this technique to create custom LED boards in the Mirror Universe project which replaced all the Switched Illumination sockets on the underside of the Playfield.

Pre-Requisites:

EagleCad 5.11 or higher (tutorial written for 5.11).
DXF2SCR from micromagic systems. (It’s Free and Awesome)
A DXF file to convert. Scroll down for a .ZIP file containing files used in this Tutorial.
About 10 minutes to do your first PCB outline.

Making the PCB shape

Please click the pictures below to be taken to a higher rez screen capture/picture.

1) The toughest part of this tutorial is creating the CAD file (DXF) which will serve as an input to the DXF2SCR tool. The author uses the Free GPLed version of QCAD to create DXF files. Teaching QCAD is beyond the scope of this document; but the basic principle is that you want to create the outline of the PCB in CAD via a series of curves or lines. Make sure you put in any mounting holes you want … and maybe even some documentation layers; like a center line or critical component locations. This allows your PCB to be “exact” without having to move holes, lines, or arcs in EagleCad.

Once you have the CAD (DXF) file; you can proceed to covert the file using the DXF2SCR tool. Start by opening the tool and selecting the input DXF file and the output .scr file. The SCR file is used later to “draw” on a blank PCB canvas. More on that in a bit. Make sure you match the units in which you created the DXF file. In my case; I almost always use inches. At this point I basically leave everything else at defaults of 1mil (0.001 inches) line widths and no offset. I leave the line with at 1mil because I can change the width in eaglecad based upon whatever I’m trying to accomplish. For much of the file; it’ll be an outline – and most people recommend you leave the outline as a “hairline” so the fab house doesn’t “charge” you for the additional 8mil width of the outline. Once you have the setup complete; click the Convert button on the left.

If the conversion is successful; you should see the number of lines, arcs, circles, converted along with a Complete message. If you get that, you can move on to the next step.

2) I start by opening EagleCad and Selecting File/New/Board… This gives me a blank canvas to create the outline on. I’m fairly sure I’ve done this on an already created board; you just have to be careful how you move the outlines and such with components are in the way. By far tho; it’s easiest that you either create the Schematic after the PCB outline, or at least make sure you don’t place parts “inside” the normal rectangle when creating the PCB from schematic.
You need to run the script created in step 1 above. This is done from the File / Script… dialog. Select the SCR you created in step 1 (or in our case rollover2k.scr) and hit open.

3)At this point EagleCad should begin executing the script drawing your arcs/lines/circles on the Dimension layer (layer 20).

At this point you should begin to move the documentation shapes to either tDoc or bDoc and then later move them to tSilk / bSilk if necessary. You want to leave the outline and any mounting holes as 20 Dimension Layer… as that is what the gerber generator uses to generate the .oln file when you commit this design to the PCB Fab houses like OSHPark.

If you do transfer some of the lines to a silkscreen layer or even a copper layer; you should remember to change it’s width to the minimum tolerance allowed by your FAB house. In the case of a 2layer OSHPark file… it’s probably 8mils (0.008 inch).

With the steps outline above; you can basically use the CAD file as an input to even align LEDs on a evenly spaced spoke pattern or really any desirable orientation.

I’m providing the input files here for you to follow along with the steps above. Download it here:
Shaped PCB Tutorial Files

This PCB outline was used in the Star Trek: Mirror Universe as the GI lighting for the Star Rollovers. The star plunger fits inside the center hole and the two holes on the side provide mounting to the underside of the playfield. These PCBs light the Rollover from the underside with Red LEDs.

Hope this tutorial helps!
John