-
Content Count
611 -
Joined
-
Last visited
About Hrafn

Spam Prevention
-
What is favorite LEGO theme? (we need this info to prevent spam)
Technic
Profile Information
-
Gender
Male
Extra
-
Country
USA
Recent Profile Visitors
-
[HELP] Generic Building Help Topic
Hrafn replied to Jim's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
@Carsten Svendsen my first thought would be to try https://www.bricklink.com/v2/catalog/catalogitem.page?P=44374#T=C doubled up it gives you 6 blades, then you can align successive pairs on the same axle at 30 degrees offset between each pair. But that gives you too much twist… hm. For augers, I have seen other builders use flex axles twisted in a helix around an axle, to give a sense of the auger’s edge. -
[HELP] Generic Building Help Topic
Hrafn replied to Jim's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
@Jundis, neither. I would use 12z double bevel gears instead - the knob wheels wear quickly and I have been told they are inefficient because they don’t mesh closely. -
[HELP] Generic Building Help Topic
Hrafn replied to Jim's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Between https://www.bricklink.com/v2/catalog/catalogitem.page?P=87408&idColor=11#T=C&C=11 and the portal axle? I would try that out and see if it is feasible before worrying about the placement of the servo - you are cramming a lot of complexity in there. -
[HELP] Generic Building Help Topic
Hrafn replied to Jim's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
@Technic tango how were you planning on steering that swing axle bogie module? Can you use skid steering on it? -
Auto stop motors?
Hrafn replied to jelockwood's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Fair enough! 😁 -
Auto stop motors?
Hrafn replied to jelockwood's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
As usual I have over-complicated things. Have a motor drive one side of a differential; have the output be the other side; add friction to the housing by meshing it with a gear on a friction pin. When the output is blocked because the lift has reached the top or bottom, the housing will spin instead of the output. You can switch any of the elements around - the motor could dive the housing, or the housing could drive the output. -
Auto stop motors?
Hrafn replied to jelockwood's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
I think so. A lot will depend on the motor, gearing, and load on the output axle. You could use a return to center mechanism like the hockey spring, or, better, Sheepo’s return to center system (I would link to it but his site seems to having issues). -
Auto stop motors?
Hrafn replied to jelockwood's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Here is a purely mechanical proof of concept, which works no matter which way the motor is turning. The motor is attached to the red liftarm (Bricksafe cropped the picture). The motor remains on all the time, but when the output axle (with the lime connector and 20z gear) is blocked, the differential housing is blocked as well, and the orange gear selector disengages the red clutch plate from the gray clutch gear. The dark gray 2L liftarm is blocked from rotating more than 90 degrees either way, and acts as a manual switch to re-engage the output axle when desired. Construction notes: The clutch plate is on a smooth 2L axle joiner, not a ridged one. Obviously you would need a rigid structure- this just shows the positions of the parts. And the orange gear selector tends to rotate slightly even when the output isn’t blocked, so it needs some friction or a rubber band or spring to resist that tendency. -
Auto stop motors?
Hrafn replied to jelockwood's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
For a pure PF solution, connect the motor to one side of a differential, and the PF switch to the other. Drive your mechanism from the differential housing. When your mechanism reaches its limit, the motor will drive the switch, turning itself off. https://bricksafe.com/files/Hrafn/technic-misc/trim.5D0469E9-E870-4EB2-8010-7C0F3476E099.MOV Note that this isn’t a 100% solution since it only drives your mechanism in one direction. -
Please help
Hrafn replied to Srg74's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This site has strict limits on file size. To upload photos, set up an account on Flickr or BrickSafe and link to the photos from here. -
Car transporter scale cars - MOCs - 3rd MOC now added!
Hrafn replied to NRE's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Great stuff! Is the front suspension based on the TC18 Porsche by @Limga? -
Car transporter scale cars - MOCs - 3rd MOC now added!
Hrafn replied to NRE's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This is really great. Thanks for sharing the suspension details, it is a very clean build in this scale. As for terminology, TC18 is a little cryptic, but specific; I have seen it called mid-scale as well. I too wold like a common term for it as I am working in this scale as well. -
[MOC] Toyota Corolla E20 Coupe (1970-1978)
Hrafn replied to dickylaban's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Such clean bodywork! I would love to see a video or gif of it moving. -
Hrafn started following [MOC] Vintage Rally Coupé (42098 scale)
-
[MOC] Mini sport car with full sized V6 at the front [Free Instructions]
Hrafn replied to SaperPL's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
I hear you. Maybe if the two parts directly under the headlights were white instead of black?- 36 replies
-
- mini
- sports car
-
(and 3 more)
Tagged with:
-
[MOC] Mini sport car with full sized V6 at the front [Free Instructions]
Hrafn replied to SaperPL's topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Making excellent progress! The one thin I am not sure about is the grill - the bit with the Bionicle teeth reminds me of longhorn cattle, which doesn’t fit the rest of the car IMO. Can you maybe flip that portion upside down?- 36 replies
-
- mini
- sports car
-
(and 3 more)
Tagged with: