To paraphrase Vane Jones, "Knowledge is of little value until shared with others."

Sunday, February 8, 2015

Finishing a CTM 4000 Baldie Kit Part 1: Inspection and Cleaning

Photo Viewing Note
To obtain the best view of the included photos, click on the 1st photo to see all of the photos in a larger size.

The kit to make a CRT/CTA 4000 Baldie will make either a trailer or a powered car. This is definitely one of those build to the photo type of kit. The Baldie 4000 were altered so much, you may need to have the photo to back up what your model looks like. Finding alterations has turned out to be a joking matter between Bruce Moffat, Terry Gaskin, and myself.

In some ways writing this is difficult because the kit I assembled was the original kit as Terry Gaskin had prepared the 3-D drawings for the 3-D printing of the parts. My recommendations for what could be done to improve the kit may have been incorporated into the 3-D drawings.

At the same time I do not wish to repeat the instructions you will received for ordering and assembling of the kit. Instead my comments are to reinforce the printed instructions you have. Included in my comments are some items of which you need to be aware to enhance your kit building or problem solving.

When you get the kit from Shapeways save all of the packaging until the kit is complete. Should you have a problem with a part where the part was not printed correctly Shapeways will reprint the part. The process of getting Shapeways to reprint the part may include your sending photos of the shipping label and other labels of the packages. Save everything!

If there are any problems contact Terry 1st before contacting Shapeways!

When you receive the parts examine all of them for problems. One of the printing problems is what I'll call "fading away". The printing of the part will look OK at one end but will start to fade as you look down the side. For example, at the right edge the rivets will be of correct size but as you look from right to left, the rivets will become smaller and smaller. At the left side there are no rivets visible.
This is an example of "fade out". The top panel has the problem while the bottom panel was correctly printed. I did not discover the problem until after the parts were "cleaned" in "Bestine". The panel with the problem has a slight curve. We do not know if the curving is related to the printing problem.

What I found odd is when I mentioned the problem of "fading away" my friend who was involved in a 3-D printing project 25 or more years ago knew about the problem. He was able to describe it to me without any difficulty. What struck me is the problem has been around for more than 25 years while at the same time 3-D printing has been known to the general public for about 5 years. In the intervening time one would have thought this problem would have been resolved. Or, perhaps the problem has been resolved and this is the best we can get today.

Another problem is the part can have a curl or bow. While some curl may be natural to the material, a curl of more than a few degrees is wrong. The test to see if the curl is too much, ask yourself if you can correct the curl. Heat of any type will not correct the curl. The correction must be mechanical - in other words, you have to "glue" something to the curled piece to straighten out it out. This includes structural brass or another piece of the kit.

My roof had a slight bow. It was corrected by attaching the roof to the body of the car. CA was used to glue the roof to the body.

The cleaning solution "Bestine" recommended for the removal of the wax from the body parts can be obtained form the web. "Bestine" is flammable and evaporates quickly. It is best used in a paint hood or in a well ventilated area.

Do not handle the solution with bare hands; wear chemical gloves! I used a large size plastic tub with a snap on lid to soak the parts. A used margarine tub will work out well. Mine was from a lemon-strawberry sherbet.
Please excuse the color of the photo. It's due to the use of fluorescent bulbs. Inside the container can be seen the "Bestine", parts of the sides, and the tweezers used. This is inside of my paint hood.

To place the parts into the "Bestine", a long tweezers were used. When parts are taken out of the solution place them on a clean paper towel. Any long tweezers can be used.
This is a side part. Note the ribbing which occurs as part of the printing. The ribbing has to be sanded flat and smooth.

I left the parts in the "Bestine" for up to 30 minutes without any problems. A new toothbrush was used to get the wax off the parts. Inspect the parts again! It was not until the wax was removed did I find a problem with the 3-D printing mentioned up in this post.
Here are some of my parts. Initially a small bottle brush was used. It worked OK but a new toothbrush with stiff bristles worked better.

When you are done with the "Bestine", it can be returned to the metal can in which it came. It's best to use a small funnel to prevent spilling during pouring the solution back into the can. 
These are the parts for my sides and ends. They are on a shop towel. I like to use the shop towels as they are soft. A couple of rolls were purchased a few years ago. Since they do not get wet and used in the normal manner, they can be reused over and over again.

The next activity is to sand all the parts. For the roof use new 320 grit garnet paper. Unfortunately I had reused some garnet paper and the process took a long time. most of the grit was already worn off.

For the sides, sanding sticks, or some of the other sanding tools covered in post dated January 1, 2015, " Some Modeling Tips etc." can be used. Sanding the various side and end pieces does not take as long as you may think.
Here are a number of parts for the sides and ends after sanding. Be sure to clean all the parts of any sanding dust.

In the next post we'll start to glue the parts together and build an endoskeleton of brass.


No comments:

Post a Comment