For 3d printing one of the key abilities of any printer FDM or resin to produce good prints is the minimum layer thickness it can print.

To explain, below is a ball or sphere 50mm diameter drawn on CAD.

   

Take the CAD file to the printer ‘slicer’ software and it turns the sphere in to a collection of plates each plate is the layer thickness set.

   

This is at 0.5mm layer to show the concept of the overlapping plates forming the sphere and the steps are quite apparent. In practice this would require aggressive post print sanding to smooth out these steps.

Same file now at 0.1mm layer (usually the best most FDM printers can achieve and the steps are much finer but still there so will still need some sanding.)

   

Resin printers can offer much finer resolution i.e. 0.02mm and the steps at this setting are now indistinct in the overall curve. 

The above is an introduction to the importance of the layer thickness if you wish to print body shells that don’t look like Lego plates stacked up.

Now for some real world testing on a FDM printer (Creality CR Mini). Taking the rear quarter of the Aston DBR1 that I sectioned for vertical printing, this part has curves in 3 planes so an ideal real world test piece as only 14 minutes to print at 0.24mm layer.

   

1st up 0.24mm layer

   

Steps clearly visible

0.12mm layer

   

0.12mm is a common setting for fine printing.

0.1mm layer

   

0.1mm is the stated limit of many FDM printers including the CR 10 Mini.

0.08mm layer

   

Most printers can go to 0.08mm which gives a good result, some can go down to a stated 0.05mm.

0.04mm layer

   

0.08 & 0.04mm, side by side

This shows the printer did achieve a better resolution than 0.08mm (and better than the stated minimum of 0.1mm) by how much I can’t measure but overall it does look better than 0.08mm layer height.

The 0.04mm setting was achieved using the standard 1.8 degree stepper motors that came with the CR10 Mini. I dialled this setting into Cura crossed fingers and watched as it printed. Why try down to 0.04mm?, this came from a comment attached to a recent printer review where the new printer has 0.9 degree stepper motors on all 3 axis including Z or layer control. In theory these stepper motors should be capable of finer and more consistent resolution than the 1.8 motors. In the comments below the review, one of the comments stated that 0.04mm can be achieved using the 1.8 degree stepper motors in older printers.

As stated all printed on a Creality CR10 Mini converted to direct metal filament drive, some frame stiffening but otherwise as it came from Creality.

Settings

Material PLA (Esun ePLA-ST)
Nozzle 200C
Bed 60C
Outer wall speed 40mm/s
Overall speed 80mm/s
100% infill.

The 0.04mm setting is interesting but the flip side is a 24 hour print time instead of 10 hours to do the Aston DBR1 complete, so for myself more practical for printing smaller objects i.e. drivers or engine detail.


Cheers 
            John

   

We're back at the Barn on Saturday for the second round of our 2023 WHO digital GT Championship. The day will feature a 4-hour endurance race, but will start with a quick-fire club car rotation to help us all learn the track - and also to give people the option of just attending for the morning.

Doors open at 9.45am for practice, with the rotation race starting at 10.15 sharp. The GT Super Pole is scheduled for midday and the endurance race to start at 12.15pm. Entry is £6 (£4 for under-16s) or £3 / £2 for just the morning session. All equipment is provided and racers of all ages and abilities are most welcome. We ask that racers aged 12 and under are accompanied by a responsible adult.

   

Mike's magnificent Suzuka layout will be making a long-awaited return to the Barn for this Digital Saturday - it's a fabulous track to drive and great for overtaking.

   

There will almost certainly be some changes to the GT line-up. These are the cars that raced last month, with the top three teams from May all having a success penalty to serve. Each of the teams is managed by one of our six Gold-rated drivers, supported by a deputy. Extra drivers are added on the day to make up teams of three or four. Every team must have at least one Bronze-rated to replicate a Pro-Am driver line-up.

For this 4-hour race, all drivers must be rostered for an equal number of 20-minute stints. A driver-change window opens 60 seconds for the 20-minute mark and closes 60 seconds after. Refuelling and tyre changes may also be carried out during this scheduled pit stop. The race is set up for 950 laps, which we expect to last approximately 4 hours. Team captains should remember that the final stint maybe shorter or longer than 20 minutes.

Two tweaks have been made to the car and tyre profiles in the RCS64 software from May. 1) The fuel tank size on all cars has been reduced by 20% and 2) Intermediate tyres now have less grip and longer brake response than previously in full wet track conditions.

   

A short video on how I setup my Hudy tire truer 

Hudy setup

Nico

   

This started out as a 1/25 pre-painted demo static kit. Something you would see in a toy store window to show buyers what the kit looks like once it's finished. It's now a slot car. It was made for a friend.

   
   
   

Just off the bench.

           

And another
   

Price £55 + PP
Please send me pm if your interested

Another one left on the shelf 

   

Price £65 + PP
please send me a pm if interested.

Sideways BMW M6 GT3

Been on the shelf for far too long, as it arrived

   

I would like £50 +PP 
Please send pm message if interested

A slot swapmeet is up this weekend in Brussels


   


Address is Ave du Haras 100, Woluwe St Pierre 1150

10.00 am to 16.00 pm

Will be there - if anyone else going - let me know ;)

Forgot to post this last week.

Link to listening options: Talking Utter Slot Podcast

Releasing episode #24 on the eve of the 24hrs of Le Mans?  It's almost like we planned it.  

Expect talk of La Sarthe, that Jenson Bunsen and his Garage 56 NASCAR entry, Stars 'n' Stripes liveries and Fassbender news. Pedro also shares his opinion of white liveries, especially Chaparrals and there's a suggestion the DiSCA 24hr slot car race should create a Garage 56-style entry for a Talking Utter Slot team running a box standard Carrera.  

Scott also reports back on all the fun of the Abergavenny slot car rally (spoiler: he came last).