Thursday, May 29, 2014

Vac-U-Form, used for making HO scale parts and details

Did you have one of these when you were a few years younger?

Well I did, and I wanted it back, so I went out and bought a used one.  Generally, when you buy something that old, there are pieces missing, and/or it does not work.  Thankfully, someone else wanted to preserve and use them, so there is a company that has some parts and rebuild kits.

Discover unique and innovative parts and accessories for your Vintage Mattel VAC-U-FORM thermoplastic vacuum machine.

what's available:

  • Products to repair damaged or defective components
  • Products to improve the performance of your VAC-U-FORM
  • Economical replacement plastic sheets - up to 30mil!
  • Helpful user information
  • Nostalgic VAC-U-FORM advertising



Share your ideas and experience with the VAC-U-FORM community.
VAC-U-FORM is the registered trademark of Lo-Tek Inc.

After acquiring the Vac-U-Form, I ordered up some plastic sheets and the full parts kit.  By now, I have about $50.00 tied up in this project.  Certainly cheaper than a new HO scale locomotive, but I didn't know if it would work.  

The projects that I had in mind were a canoe, a row boat, and making wind shields for automobiles.  First, however, I gave the machine a try, just to see how it worked.  I tried it without the upgrade/parts kit, and it lacked enough suction to pull the plastic down around the molds, or so I thought at the time.  Although I was probably right about the suction, even with the upgrade kit, things did not work right, as I was not getting the plastic clamped in the holder tight enough.

The upgrade kit includes and plate to cover the hat plate, thus holding in the heat, and getting the clamp hot.  The plastic sheets available now do no have holes in them to fit the prongs on the clamp, so the clamp must be hot enough to melt in to the plastic in order to hold it solid.  I hope that makes since?

 The used machine I bought did not come with any molds, which was fine, as the only one that I remember that might have worked was the boat.  Regardless, I had to make my own molds...bring in the 3d printer.  I was in need of some tile roofing for a project, and did not find any HO scale that I liked.  So, that and the canoe mold were in the first couple tests.

 This is the first one that came out almost reasonable.  The tile to the left could be cut in to strips, and although the plastic did not pull down tight in the corners around the canoe, it looked usable.

 The plastic supplied has a glossy side and a flat side.  The black sheet in this picture has the glossy side up.  To show the cut lines, I used a white paint pin on the black plastic, and a pencil on the red.

 Once cut out, it is easy to see the backs of the boats were not formed well, and will have to be built up from styrene.

 I am adding some details and reinforcement to see what looks right.  I ran out of red plastic, as I wanted to finish the well roof before I did this post, but it will be another week before I get more plastic.  I will do a post on the well by itself at a later date.

 I cut off the back end of the boat, and replaced it with some styrene, which incidentally, solvent welded to the Vac-U-Form plastic just fine.

You can click on the pictures to make them larger.
 I do have some cap shingles I formed, but can't put them on till I get more red plastic...

 which I would have had, if I had not screwed up this sheet and another.  The is what happens when the sheet is overheated.  The glossy area on the right is so thin it is clear and it broke open, breaking the vacuum.  Maybe two of the rows of tile will be good, but I needed four to finish the project at hand.  The other pieces are to be cut for caps.

This is about the best I have gotten!  For the record, this was preheating for 15 minutes with the plate to hold in the heat in, in place.  Drop the plastic in and use a spring clamp to hold it tight, wait another five minutes, then put the plate on for 15 SECONDS.  That's right, 30 seconds and it melts through like the shot above in red.  If you look close, you can still see some gloss on the right side where it got a little too hot.  Note that the back of the boat is formed perfectly.  I don't think that with this technology from the 1960's I can get much better than this.

It is also important to point out that with each failure in the Vac-U-Form process, I also found issues with the molds.  This is the third rendition of both the boat and the canoe molds.  Adjusting for air holes and getting what was to be the final product down as close to the surface as possible.  Each sheet costs about a quarter, so when a print fails, you just wasted about 20 minutes and threw a quarter away. :)

More later as I get these projects finished up.  Not sure what else I can use the Vac-U-Form for, got any ideas?

Saturday, May 24, 2014

LazerBlade kickstarter crowd sourcing project

I have no affiliation with this, other than that I have some interest in it for cutting roofing, windows and doors.  It looks like it will be funded in the first day, 93% funded in 23 hours as I write this.  It is small, and not very powerful, but it will cut up to .8mm (1/32") plywood, which would work for cutting layers to assemble windows and doors.  Also, for me, it would be nice to cut shingles from paper.  I would love to hear from people that know more than I...which should be easy, since I know almost nothing about these things.

Link to the kickstarter project.

Sunday, May 18, 2014

Frisco Section House, 3d Printed in HO Scale

I have started drawing and 3d printing more prototype structures, and I wanted to have a Frisco and a MoPac prototype for a clinic I am doing later this year at the joint MoPac/Frisco convention in beautiful Joplin, MO October 9, 10, 11.  See and  For 3d printing on my Afinia printer,, I consider several things:
     - Can the entire building be printed in one piece on my printer bed...this limits the size to about 4-1/2" square for the foot print, and 4-1/2" in height.
     - What type of siding is on the structure?  I can design and print vertical siding, but it has to be exploded in to pieces and the pieces have to be oriented to print horizontally.  A good example can be seen in this post:  To make lap siding print clean, it is best orient the item to print upside down.  
     - Overhangs and gable ends mean extra work exploding the structure and orienting it for printing, but most things can be worked around.  Sometimes, however, why 3d print it, I only need one, and it would be quicker to build from wood or styrene.  All options are considered.  

This is the plan for a Frisco, SL&SF, section house, as published on the web site.  I was not able to read the actual dimensions, and in reality, I would need to size the building to fit on my printer, and, as such, it would be a good size for the compressed area of most model railroads.  In other words, adjustments and guesses were made.

An over all view of the building to be 3d printed.  With the limitations of my printer, I decided to go with Tichy windows, which are injection molded, and much finer than I can print.  And, for what it's worth, Tichy products always seem to be in stock, unlike other manufacturers.  Their web site provides all the dimensions needed.  The final building is about 20' x 30', i.e. the rooms are all 10' x 10'.  I would assume they were larger than that on the prototype, but I really don't know.

Once the basic design is done, then I start thinking about what it is going to take to get the item to print correctly.  Not to say that I don't consider what it is going to take to get the item to print correctly as I am working on it, but at this point I look at exploding the project and how it will need to be oriented.  As I said above and have shown before,, lap siding is best printed upside down, so, here you can see how I have drawn the gable ends to be removed.

As I am constantly learning with each new item I print, I have figured out that if I make the walls thin to speed up the printing process, then I need to add bracing to strengthen the walls.  Now, again, from trial and error, I design the bracing to be printed with the walls.  Also, where two surfaces will need glued together, there really needs to be 6-8" of surface area, in HO scale.  The ABS that I print with will solvent weld, but not as easily as styrene, thus it works better with a little more surface area.  As you can see in this view of the drawing, I am using the interior walls as bracing, as view blocks, and I am printing the interior doors in place.  The interior walls do not go clear to the bottom, so there is room to add a floor.  For display purposes, I have not added a floor at this time.

Here is what the files look like I use for printing the section house.  All the siding is upside down to eliminate support material and want to see some sagging siding...  I did have to create supports under the turned upside down gable ends, but that will be cut off after the printing is done, and before assembly.

An in progress shot of the printer running.  You can clearly see the support generated to create the window and door openings.  Total print time, with the gable ends, is over 6 hours, with the walls taking over 5 hours.  I believe, at the time I printed this, it was the longest single print I had done up to that time.  This past Friday night, I did a print job that lasted over 17 hours!  That building will be part of the clinic I will be doing at the Frisco and MoPac meeting.  

The assembled house, with the wood porches added.  In this under side view, you can see the interior walls, interior doors and the bracing, all printed in place.  

I used colored paper for the roof, wood for the porches, and styrene for the rafter tails.  The chimney is also 3d printed.  Notice how nice the Tichy windows look, particularly when compared to the one I print on the Afinia printer, see,  

The back door.

A final shot.  I have a few things to do to it before planting it in a layout, but it is ready for a clinic display.