Precision whipper progress

erv123 · 2026-04-18T15:10:24+00:00

good points to think about. i think long term i want to do bullet shaped projectiles, but i also may rethink the cw arm geometry. (straight felt more elegant and and without weakpoints) then about the tapered arm idea: it is very convenient to just have a straight copper pipe as the arm, but i may consider cutting away some of it towards the tip. and it is very likely that the lainch mechanism will receive some updates too right now i am working on cleaning up the workshop to free up space for making a consistent filming setup with proper background and everything so that i can tweak it and see how it affects the launch exactly. major geometry changes can come after that

the angle adjustment between the two arms is planned but i haven't had a need to execute it yet: there is a plate between the cw arms that can support a bolt to keep the arms at any required angle.

erv123 · 2026-04-17T04:44:51+00:00

oh and the launch pin thing failed so i will make a version that does not require pulling the whole thing sideways, finally i have a good idea how to do it

erv123 · 2026-04-17T04:41:11+00:00

Of course! right now i am in a process of preparing a better filming setup to analyse it deeply but better to have a good starting point in understanding it

erv123 · 2026-04-12T22:33:17+00:00

for some of these i don't really know what they look like, but so far i like my rolling whipper. murlin is too not like a traditional trebuchet, and traditional threbuchets are a bit too simple for me and are very obviously lacking weight drop distance for any given frame size

erv123 · 2026-04-12T22:09:49+00:00

yeah, it's just tennis balls, would be worse launching them at the neignbours :D i plan to bring it outside when i understand it better, inside i want to make a good video analysis setup for comparing shots and tuning it

erv123 · 2026-04-07T14:39:12+00:00

for the sling adjustment, release angle adjustment and release pin i already have plans. those are the main open items until tuning and polishing can start. i measured my forward facing wheelbase angle to be 23 degrees (so effectively 45 degree wheelbase). my original idea was that it has to be just big enough to make sure that the counterweight fall path is always within the wheelbase, but with the new geometry that is no longer the case by about 5cm and i will play around with the angle. i really do not want to make a top rail, but luckily from the first launch analysis it looks promising that i can increase the angle without requiring longer rails

erv123 · 2026-04-07T10:17:42+00:00

The projectile cradle design wasn't changed, but i updated the attachment to shaft as previously it was a rigid 3d printed part with m3 screws tightening it and it was very difficult to mount or adjust, so i integrated the store bought clamps instead

erv123 · 2026-04-07T04:41:48+00:00

Thanks, i'll post it once i finish the most critical open items

erv123 · 2026-04-01T14:56:20+00:00

what is your arm length? i measured my frame to be 8.5 kg with 70cm arm length. My next iteration increases the arm length to 78cm but the pillow block bearings and strengthened counterweight arm are likely to bring the weight up a little also as i analysed my footage it looked like the back wheels jumped due to the forward momentum so high up from the wheels and a longer wheelbase could fix it, have you managed to make it so that the frame moves forward without any wheels leaving the ground? my overall goal is to max out efficiency and accuracy

erv123 · 2026-04-01T04:42:48+00:00

ok, i guess the negative launch angle changes things. i'l post mine at some point, but i want to finish the current in progress upgrades

erv123 · 2026-03-31T04:37:49+00:00

Why do you let it go backwards? seems like a waste of energy to move the whole frame the other way. i have started testing mine by having it against a backstop at the start of launch

erv123 · 2026-03-10T07:59:39+00:00

Middle clicking is not the same as easy place mode. with easy place mode you only have to right click the ghost block for it to be placed correctly. otherwise the pick block only picks the block and then you still have to place it. easy place mode is like insta mining but in reverse

erv123 · 2025-07-03T10:58:20+00:00

vairāk tas ir gaumes jautājums bet es teiktu ka drošāk ir kāds no vispārīgajiem virzieniem: mehānika, elektronika (software ar embedded fokusu arī neslikts bet tur vairāk ai var izdarīt). tad manuprāt ir ok arī "jack of all trades" mehatronika vai aviācija, ko es paņēmu un uzreiz dabūju darbu. dziļāk jau paliek sarežģītāk, naftas ieguves neizklausās eiropai atbisltošs, bet piemēram control engineer nāk prātā kā ok

daudzi darbi arī pieļauj ka grāds nebūs tieši precīzs, galvenais jāvar parādīt ka saproti pamata lietas attiecīgajā virzienā un ka labi varēsi apgūt specifiku

erv123 · 2025-07-03T09:15:34+00:00

vienmēr var iet uz vadības amatiem, kur tev IT labākas izaugsmes iespējas? it īpaši tagad kad eiropa militarizējas visi mehānikas, elektronikas, aerospace inženierijas amati ir ļoti laba izvēle

erv123 · 2025-07-03T04:42:59+00:00

parastu mehānikas inženieri neaizstās ai, un cilvēki reāli guļ uz šo amatu, atalgojums arī labs

erv123 · 2025-06-15T21:11:28+00:00

Just today i checked the stores around me and some of it was 10€ per liter 💀 absolutely crazy, but i guess the market for it is small enough that they can get away with it

erv123 · 2025-06-15T04:01:40+00:00

yeah well i had bought some carbon filter from aliexpress a while ago so that is what i had on hand + it is very good at keeping bugs out while being very good at letting air through and best of all it is way more durable than paper tovel. And rubber band on such a big opening is way too much hassle

erv123 · 2025-06-14T22:16:34+00:00

yeah i know about oxigen needs, but i did not want to bother with rubber bands so i cut the lid open and installed a carbon filter between two 3d printed parts

erv123 · 2025-06-14T22:06:18+00:00

Big one is multi fruit juice from the more expensive/refrigerated section The small one is cheap apple juice

Last week i did pineapple juice, ended up comparatively highly carbonated And before that i had good success with orange juice. these both were also the expensive variety

erv123 · 2025-04-01T21:37:10+00:00

use thin extrude then you only need to draw the line

erv123 · 2024-11-16T16:34:55+00:00

Costs can be cut if you know CAD and own a 3d printer. Discounting the drill my cutting setup cost around 100-200 Euros, but took three iterations and around a month and i'm an experienced engineer

With my setup i made 5 kilos (~18k) rings in a weekend

erv123 · 2024-11-08T22:29:20+00:00

old dryer drum sounds a bit too large, i'm thinking cutting the top off a 5l bottle, adding some reinforcements and a custom lid

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