PCB chassis once more

[walker]

I hope you won´t be bored by my article - it is quite picture heavy. But working with PCB is my absolute favourite.

Yes, it is an excellent chassis material. Easy to saw, cut with cutting discs, drill, file sand, glue, even solder.

You can select single – sided or double sided copper layer. Sometimes it may be better to use double sided PCB, for example if you build a chassis in 24th scale, where the sideforces and crash forces on the rear axle pillow blocks are much higher. Double sided PCB can be soldered to the base plate on both sides, what strengthens the joint.
Normally single sided PCB is appropriate.
Somewhen I found a PCB with a blue carrier, what looks quite good and clean as a chassis underside.

Well, you have various possibilities how to get a PCB chassis.
The easiest way is to contact Milan Tomasek ( MTR 32 ) and buy a chassis or chassis kit that fits your body resp. your requirements.






I have taken another path. After having tested one of the first chassis Milan had made I decided to go my own way.
I did two different things

.
1.I asked Milan to make plates that have the rear axle bracket holes, motor bracket holes and motor hole only. When I received them, I engraved the chassis center line and the axle center line into the plates.

2. I scanned these two different ( angle and inline ) kit plates I had ( they were from the very first series, in the beginning of Milan´s “career” ) and redrew only the rear part – motor bracket holes, axle holder holes, motor hole, center lines.

Now I am able to construct the rest of the chassis – width, length, any separately moving parts etc. myself, after my specs.
I print this drawing and stick it on the plate, exactly adjusted on the two center lines – axle and chassis.

As an addition to these two basic chassis variants ( inline and anglewinder ) I let Milan make the fitting axle and motor brackets and guideholders as well. So I have absolut precise main parts but can build my chassis as I want to.


2. Besides that I let Milan make a few plates of two newer chassis including the above mentioned holes PLUS the brackets. So I did not have to redraw any scans.


Of course I constructed my own chassis as well. The procedure is
- drawing with a CAD or whatever precise program
- copy it a few times
- cut out the pieces that have to be cut from the PCB then
- stick all cut out paper parts on the plate
- cut, file, drill etc.

BEWARE OF THE VERY DANGEROUS DUST ! USE A PROTECTIVE MASK AND SAFETY GOGGLES, OF COURSE, AND POSSIBLY AN EXHAUST SYSTEM !
Mine is built from a vacuum cleaner, very simple but working efficiently.

Here you see some examples of chassis.

First a Saleen , then a PANOZ LMP with front drive ( it works extremely well ! ) which was lightened later, then a Maserati, whose chassis is half original and half PCB. As you see I like to experiment.
Finally – since my focus is on 43rd scale now, a 43rd scale chassis, sidewinder, with drop arm.

Saleen





Panoz LMP





Maserati







43rd scale











I hope you havent´t fallen asleep...

Roland

[Kemtronracer]

"I hope you havent´t fallen asleep..." - Nope, I like it. Tell us more please.

[MrAdept]

Very much enjoying the topic.

Have you done anything in 1/24th with the pcb chassis?

Do you and Milan have a CNC router for accuracy?

Mark

[walker]

Well, the first pictures show chassis / plates from Milan. He uses CNC.

I design and make my chassis manually, just like the pictures of the 43 rd chassis show.


Roland

Ah, I forgot - the first works with PCB date back to the late seventies, early eighties, when we built wing car chassis from a composition of piano wire, brass and PCB. In 24 th scale, of course . The "discovery" of PCB for wing car chassis was somewhen after the Worlds in Stockholm then.

[TowerofPowerDavid]

Fascinating! Look great and strong. please tell us more! Kemtronracer, we should each build one !

[walker]

Maybe you will love this material as I do...

One thing - of course all the pushfits are glued together first. It is difficult to decide what glue to use.
Quick curing superglue is not advisable because one should be able to readjust the parts as long as the glue still allows it.
This means using a slow curing superglue or a 2k - glue is best.
Soldering these joints where the copper meets is not absolutely necessary, but the solder in the fitting edge provides an extra bend protection to the joint.
But be careful ! The copper layer is very thin and glued on, and it reacts with too much heat by peeling off. So soldering should be done quickly and with a good flux.
And most important - just as with all soldering joints - is neutralising the joints finally. I first wet it with water, spread baking powder over it, scrub it with a toothbrush and finally wash it with dishwashing soap and rinse it. A hairdryer is good for drying because it blows tiny amounts of water out of edges or tubings.
If you have any moving parts, hinges or whatever, oil them before you clean the chassis.

Roland

Ah yes, be patient and precise with making the rectangular holes and tenons(?) for any pushfits. The tighter they are, the more solid the joints.
And very often - I would say nearly always - it is necessary to stiffen the chassis lengthwise. Look at my Panoz - chassis or the 43rd scale.

[gsmea]

Walker, this is gr8.

Talk some more..... this is exactly what I was looking for to do my Jaguar XJ220.

Thank you,

[nhdungeonracer]

That's pretty neat stuff you're doing here.

[walker]

Well then...

On the third photo of the Maserati chassis you see a yellow arrow.

It shows how I very often use to make my guide holders. Normally people tak a short piece of tubing and glue it into to the guide holder. But what if....the diameter of the guide shaft and the available tubings don't fit or you haven't any tubing available ? And is it necessary to buy a length of tubing of which you may need only an inch then and the rest lays around ?
I simply take cut off PCB remains, shape them to fit onto the base guide holder, glue them to stacks and drill the shaft hole. Sometimes, when I' m in a good mood, I drill two tiny holes - 0.6 - 0.8 mm vertically into the stack and glue in two pieces of piano wire as an extra securing.

It is very important that the two rear axle brackets ( "pillow blocks" ) are connected by any kind of bridge that is u- shaped and placed in between the two brackets to protect them against side crashes. This is easier to be done with sidewinders and anglewinders because there the gear is ouside the brackets, with inline drive one has to attend that the bridge does not touch the crown somehow.
I make it from cardboard first and adapt it until it fits and then transfer it to the PCB. ( The same procedure as any time...) :D
I have learnt this by sad experiences...The only chassis to be seen in my article that has this bridge is the 43rd scale one. The other two RTR helped me with my learning process then... :mrgreen:

And last but not least - do yourself the favour and countersink all screws on the underside of the chassis carefully. The PCB you use should be min.1.5 mm, so it is thick enough.

Roland

[dreinecke]

That is some seriously impressive work! Nice job and thanks for sharing this. I'm always very interested in learning about how others are doing things.

[bill from nh]

Roland, is that an SCD chassis jig shown in the 43rd scale photos? Thanks.

[gsmea]

Again fantastic stuff. Great work and thank you for sharing your knowledge and experiences with us.
Gavin

[walker]

[pfuetze]

is that car in the last picture a 1/43rd Heller kit Austin Mini?
Did you ever finish the chassis? Can you show pics? It looks great!

[waaytoomuchintothis]

What gets my attention is that people were using this material way back. When I started building with this stuff about 4 years ago, I thought I invented it! Of course, I don't have access to CNC nor CAD. I just cut out parts and squared them up with a file. The flex in this stuff is impressive. I made a '53 Ford with so much flex I had to make a limiter to keep from rubbing the body.