23 replies to this topic

[tjallen]

I was staring at a scratchbuilder's soldering block and wishing I had one, when I realized that I could have one! 3D printing is very exact, in Tinkercad I can specify my design in thousandths of an inch, and it seems a simple enough task to create one. Also, I had noticed the Shapeways materials list included porcelain and sandstone, either of which might work for a soldering block. Another project was born!

 

I did a quick, rough copy of the chassis jig of my dreams. Simple, with chassis lengths every half-inch from 3.5 to 5 inches, and holes for axle holder pins in 1/8 and 3/32, and a T-slot so I can use wing-nut holdfasts, or screwdowns, or whatever they are called. Voila!

 

 

So I sent the design up to Shapeways for an evaluation, and imagine my sticker-shock when the prices list for various materials appeared: PLA  plastic $165, Lego-like plastic $215, acrylic $1200, stainless steel $1900!!  Sandstone was $300, and my block was too big for porcelain.

 

Well, that is unaffordable, and not cost-competitive with other methods. Sensible design changes might help, I hoped. I shortened and narrowed the length and width. I reduced the height. I hollowed it out, to reduce the amount of material. It cannot be made too thin, however, as it is supposed to act as a heat sink. So here is version 2, the hollowed and shortened dream block:

 

 

Alas, it seems this project is still too big for my budget!  PLA  plastic $88, Lego-like plastic $125, acrylic $600, stainless steel $1000. The project-desirable sandstone was $155, and porcelain $108. Still too expensive for me, and this is before cutting lots of pins, making axles and dummy wheels, and more.

 

So I continue to look for appropriate and affordable projects for 3D printing and slot cars. I know I said, learn by doing, trial and error. I suppose this one is a failure, although we should expect prices to be lower in the future.

[Samiam]

So I continue to look for appropriate and affordable projects for 3D printing and slot cars. 

 

Personalized 1/24 driver's heads?

[Bill from NH]

Jim, the first chassis jig drawing looks good, it just isn't economically feasible to make using 3D printing. I don't like any of the Shapeways material choices.for soldering on. In my opinion, this chassis jig's design would be great if drilled & machined into a hard countertop material, such as Corian, Fountainhead, etc. The second chassis jig looks too small for building 1/24 scale cars. There isn't room for jig wheels to be placed outside the pins for the axle uprights. Pin holes that close to a jig's edge are apt to break out easily & have. I also think a hollowed-out jig like your 3rd drawing shows wouldn't stay flat for very long. It doesn't appear that 3D printing can be easily used to make a jig that has pins for material placements, but it might have applications on something such as Chris Briggs' Chassis Jig which uses aluminum casings on sliding steel rods.

 

I don't know about Sam's driver heads, but I'd like to see the Shapeways cost for printing a 16D endbell, somewhat similar to Mura's.

[Dave Crevie]

If it is plastic it won't hold up to the heat of soldering.

[tjallen]

If it is plastic it won't hold up to the heat of soldering.

 

Correct, you cannot solder on these plastic ones. Normally, I would make a plastic test version. Here, I cannot even afford to make the test. :-(

 

P.S.  I see some solder blocks made from a plastic of some kind, but it is not this kind, not PLA or acrylic. Could they be nylon?

[Dennis David]

Jimmy, What you're doing is exactly the process that I went through and that led me to realize that I really needed a CNC Mill AND a 3D printer. The only difference is I came at it from the other end and realized I needed a printer also.

[Bill from NH]

 

 

I see some solder blocks made from a plastic of some kind, but it is not this kind, not PLA or acrylic. Could they be nylon?

 

Those jigs made with the plastic-looking material are actually one of the solid surfacing materials for countertops, such as Corian. Heat will eventually scorch them & over time, they don't stay flat. It's the best material currently being used, but I still use a Champion slate jig.

[MSwiss]

Hi Jimmy,

First of all, big thanks for posting all your real life experiences with Shapeways and 3D printing.

 

As you have figured out, a chassis jig is about the worse choice for something to 3D print.

 

I'll add a few things about jigs below.

 

It cannot be made too thin, however, as it is supposed to act as a heat sink.

No, they are not.

 

If that was the case, guys who sell CNC cut ones, would use aluminum.

 

Soldering on something that soaks up heat, just requires using a hotter iron.

 

That said,in the case of corian, and corian like material,  it does have to have to be thick enough, to not eventually warp, as Bill alludes to in his last post.

 

Backtrack made his original jigs from 1/2" nominal (.480") material.

 

It didn't soak up heat, but with the 200-300, that were sold at that thickness, a handful of guys complained about eventually warping.

 

When Precision copied the Backtrack, multi-pin, Jail Door jig, he made it from a thicker material.

 

Despite it soaking up more heat than ours, the top guys, that built a lot of chassis, did like them, because they did not warp.

 

So Backtrack switched to a much thicker, .960" material, and the occasional complaints of warping, disappeared.

 

 

Those jigs made with the plastic-looking material are actually one of the solid surfacing materials for countertops, such as Corian. Heat will eventually scotch them & over time, they don't stay flat. It's the best material currently being used, but I still use a Champion slate jig.

I've never heard of the Precision, or the thicker Backtrack, warping.

 

IIRC, the Champion jig had asbestos in it, so we will not see it again.

 

Regardless, the guys cutting ornate jigs, don't have any interest, eating up cutting tools, on material like that.

 

If I can find it, I'll post a pic of the nice, locally made jig, I bought in late 83, or early 84,  to finish up perimeter chassis #001.

[Dennis David]

Mike, the ornate jigs you refer to, are these also made of Corian?

[tjallen]

 

No, they are not.

 

Learning more every day! Thanks for all this info.

 

Looking back, it was a Precision block I was lusting after, but simplified somewhat, and with some front wheel pin holes useful to 1/32 added.

 

I'm sure the block I want will appear on ebay, or I can find one at the fine manufacturers. I wanted to learn more about 3D printing, as you have surmised!

 

Jimmy

[MSwiss]

Mike, the ornate jigs you refer to, are these also made of Corian?

Yes.

 

The Backtrack is Corian.

 

Precision alternately calls their jigs as made from "solid surface material", or Corian.

[Samiam]

Has anyone tried machining ceramic soldering plates as used in jewelry repair?

https://www.ebay.com...tMPdM_aSWGYALeg

 

There are the honey comb plates too. Duffy showed how he made hold down clips to use on these for chassis work.

https://www.ebay.com...5.c100005.m1851

[James Wendel]

I use a ceramic "honeycomb" plate like Sam mentioned.  Mine is 5.5" x 7.75" and I have soldered on it many times with a mini-torch with no ill effects, aside from some discoloring.

 

https://www.ebay.com...pYAAOSw34FVB4Yi

[Bill from NH]

Many of the HRW 1/32 racers build on ceramic honeycomb plates. They have a thread "hot-listed", but most of the photos disappeared thanks to P-bucket. There is at least one chassis building video using a honeycomb plate on You Tube. These ceramic plates make a very good pin jig. You can buy machined steel & ceramic pins that fit the holes, but .047 piano wire & 18 ga. brads work also. These plates come in different shapes & sizes. As James said, they can be used with torches & soldering irons. They will withstand about 2000 F.

 

Sam, I would think these ceramic plates could be made "dead flat" if one used silicone-carbide paper on a known flat surface (table saw, jointer bed, plate glass, surface plate, etc.), If you had access to a diamond plate, it might go faster. I'd check them with a good straight edge first, I haven't heard that many needed flattening.

[MSwiss]

IIRC, the one I bought used .055 wire, and it didn't fit quite perfect.

[Bill from NH]

I have two that both take .047. There must not be one industry standard.

[MSwiss]

Are they a good fit?

[Dave Crevie]

Ceramic materials can be very tough to machine. It is very hard, and that is why ceramic is used for certain types

of cutter inserts. For drilling, diamond point drill bits are recommended.

[Bill from NH]

Are they a good fit?

 

Yes, & so are box of brads I got for $2-$3 @ HD or Lowes. Did you try the machined pins that are sold?

[MSwiss]

When I bought mine, I don't remember machined pins being available.
 
Regardless, what that item needs for slot racing use, is a machined pin with a 3/16" post attached to it.
 
I was going to have Geary make some, but I didn't think he would want to go in competition with himself.
 
Here is the nice slate jig I bought in 84.

 

With the scribed lines on the side, and being raised, to facilitate using rubber jawed spring clamps, it was great to build perimeter chassis on.

[Dennis David]

As Mike or someone else eluded to before, I can't see ruining $50 end mills to try making one of these. 

[Dave Crevie]

You wouldn't use end mills for the drilling. Only the slot, and that doesn't have to be full length.

[Bill from NH]

Here is the nice slate jig I bought in 84.

 

 

Yes, that is a nice jig. Personally, I'd have a problem building on the stilts, but I understand why you use them. When Jerry owned JK, didn't he sell a similar corian jig, but without the stilts & scribed lines? I forgot I had one of them. I put rubber feet on mine to keep it from skidding around. I noticed in his videos that Tony P. likes his jigs to skid around.  My solution to having a 3/16" guide post on the honeycomb ceramic plates is to turn a 3/16" post with a spacing flange at the bottom, using brass or aluminum & center drilling it to fit a length of glued in .047 piano wire. I use the same type of removable posts with my Champion slate jig. I could make other diameter posts if I was going to use 1/32 scale guides.

[Dennis David]

For those size holes that's correct. But you do often use endmills to make holes.