Resize a STL File For Me

[MarkF]

Just finished assembling my rooftop air conditioner and thought I would share some new creations:

  end-of-track buffer +++ air conditioner +++ 6 yard trash dumpster +++ 4 yard trash dumpster

[bostonman]

Those look great. Seems this is a serious hobby for you.

I printed the PCB box you "fixed" (more like made). First I printed mine that you fixed and it was horrible. When I do a 3D model, for some reason in my mind 0.25" seems tiny. As it printed I realized the dimensions were horrible. Also, I stopped the print because it began printing the top layers before the walls, but it left half as infill and the other half as solid.

The one you provided was excellent, however, my printer is in need of calibration because I checked the PCB with micrometers and it was just under 2" x 3" (update: I made the PCB 2x3 but wanted to confirm it wasn't made larger) but the PCB didn't fit. I had to make the model slightly larger and then the PCB fit.

[MarkF]

I have to check my printer again.
If I remember correctly,  the outside measurements (i.e. outside of a cube) are a few thou different from an inside measurement of a shell/pocket/opening.

When you do your calibration, try to pick a distance that covers most of the bed.  The larger the distance you measure for the calibration the smaller the error you will get.

[MarkF]

I forgot to mention that if you size the holes just right for the PCB mount, you can use a #4 machine screw without a nut to hold it in.  You will eventually wear out the plastic if you remove them a lot.  I have also used small #4 wood screws directly into the PLA.

[MarkF]

Those look great. Seems this is a serious hobby for you.

FreeCAD and I spend a lot of quality time together.   

It's just that the model railroad hobby is very expensive.
That 'railroad crossing' sign I showed a few posts back costs $6.00 while I can print it for pennies.
All these things for the railroad are so small.  I'll end up with a resin printer if I'm not careful. 
When I first started the hobby in the 80s, I could get Atherean 'Blue Box' boxcar kits for $5.00 each.  Last month I picked up a box car for $22.  And the prices just go up from there.  Non-DCC locomotives were $25 and now most start at $150.  A locomotive with DCC and sound start at $300 for most.

I need to get some people, cars and trucks but you easy pay $10 or more for a plastic truck or a half dozen people.
(Those cars and trucks in my photos are Mattel toys from when I was a kid and are a little too big for HO scale.)

Here's a new photo of those models for the layout that I posted over in the 'Model Trains' thread.
Plus lots of photos of other things I've printed.  Also, I made shorter walls for the office building.

[bostonman]

It's great you are able to connect to your hobby by making many pieces. It's probably nice to buy the pieces, but much better when you make your own.

Most likely I'll use a nut to hold the PCB box. Technically, if not for having a 3D printer and 3D layout "skills" (skills = attempt a design, mess it up, come on here, and have someone create a much nicer piece), I would have just stuck it in a hobby box or screwed it using standoffs.

As the silk screen on the PCB states, this is for a frequency counter. Long story short, I attempted to use this counter some time ago, noticed segments weren't lighting on the VFD, built a daughter board to incorporate a replacement IC (see attached photo), and now want to add an external display should the VFD fail in the future.

The PCB takes the display signals, puts them through a buffer, sends it externally, and then a receiving buffer will send them to an Arduino.

I wasn't sure if laying out two boards would be cheaper than one large, but, since size wasn't an issue, I put both circuits on one board and populated only the necessary components.

This project began over nothing more than opening the unit to see if the missing segments was due to a bad connection. Before long, it took over all my projects and it's been disassembled for nearly a year.

As for calibrating my printer, every time I think about calibrating it comes the need to use it and/or I'm caught up with other projects.

It's never been calibrated, so a learning curve may exist. Usually being off by 1/16 or 1/8th of an inch doesn't affect my prints, but I'd save time and material if a 2" x 3" PCB box really printed the correct size. As probably mentioned, prior to hearing about calibrating the printer, I thought incorrect print dimensions was just due to the low quality printer. It will be great to get much more accurate sized prints though going forward.

[bostonman]

After making some size tweaks, I printed the saw leg. It fits perfect but I plan to increase the base thickness a bit and reprint.

[MarkF]

Good
It will be interesting if the legs cut through the filament.

Hence, I suppose the reason for "I plan to increase the base thickness a bit"

[bostonman]

Attached is revision C which is size edits from the original (Rev A), thinner slot opening for the L frame (Rev B), and now Revision C which has a thicker base.

I managed to follow along just enough to make the size changes, but still impressed you were able to pad it at an angle. When I made some size changes, it seemed the triangle base wasn't moving with the padded angled part. I had to move it manually, size it differently, and basically did a trial and error approach until it "just looked good".

Also, you padded the base symmetric to the plane at 0.08". I increased it to 0.12", but removed the symmetric to plane along with reversing the pad.

As you can see from the attachments earlier, it came out looking identical to the original, so you did a fantastic job.

Making the base thicker was concern that sliding the base on hard surfaces will cause the PLA to wear out. I plan to print the first four layers solid along with 80% infill. Most likely I'll add some hot glue to keep the foot on the L frame, but it was quite tight; I actually had to tap it with a hammer to slide it off.