Retrofitting an old loader wagon so it fills buckets with wood-chips at the press of a button.

Motivation

Current situation

We don’t have a chip-fired heating system yet, but we still wanted to use some chips alongside firewood. The workaround was to dump chips on the floor and fill buckets by hand once a week (about ~25 buckets in one session). It worked, but only as a temporary workaround.

Problems

Mess → chips everywhere → constant cleanup
Dust → health risk, not great in the hall
Heavy work → loosen, shovel and lift ~25 buckets in one go
Slow → loosening layers + filling takes real time
Space → big pile blocks space in the hall
Compaction → chips bind into a solid layer; must be broken up before shoveling
Overall → working with buckets is not elegant, but it kept things running for now.

Hand-filling from the floor: dust, mess, and extra effort

This is a temporary bridge until a proper chip-heating system is installed.

Idea

Repurpose an old loader/forage wagon instead of scrapping it: Use the scraper floor, add an auger, and fill buckets with one button press.

Original wagon before retrofit

Front view of the reused wagon

Why this makes sense (for now)

Semi-automatic and effortless → place bucket, press button
Less dust → fills straight into the bucket; no loosening compacted chips, no shoveling
Cleaner → no chips on the floor
Refillable → load at a remote pile with the front loader
Portable → park it where it’s convenient
Reversible → bolt-on attachment; wagon (incl. pickup) stays usable later

Result (second test):

Components & Specs

Mechanical

Base wagon – HAGEDORN
- Type: loader/forage wagon
- Year: ~1966
- Capacity: 4 t
- Features: scraper floor, pickup (kept)
Auger
- Diameter: Ø 250 mm
- Pitch: 250 mm
- Length: 2 m
- Flight: right-hand (R)
- Inner pipe: 60.3 × 3.65 mm (2″ OD)
- Price: 260 EUR
Bearing blocks (40 mm UCP)
- Count: 3× total → 2× fixed, 1× floating
- Radial rating (each): 23 kN dyn / 16 kN stat
- Axial capability (each): 3–4 kN (≈20% of radial)
Turning parts
- Custom drive shafts and adapters (motor, auger, PTO)
- Taper-lock seats and 40 mm bearing journals
Side walls & sealing
- 8× reclaimed wooden interior doors + OSB panels for side wall paneling (chip-tight)
- 2× 60 cm red street broom brushes as rear scrapers/seals where the scraper bars pass
- Old potato sacks packed into the corners for additional sealing

Built rear assembly attachment with auger and broom

Walls lined with reclaimed wooden doors

Drivetrain - Scraper-floor drive

Motor: 3-phase Dahlander
- Manufacturer: Baumüller Nürnberg
- Power: 1.1 / 2.2 kW
- Speeds: 460 / 920 rpm
- Voltage: 380 V
- Frequency: 50 Hz
Resulting speeds: PTO ~160 / ~320 rpm
Sprockets: z12 → z35
Shafts: 32 mm motor, trailer PTO (custom adapter; chain blade on old PTO fork)
Chain: 10B-1

Scraper chain and sprocket layout

Drivetrain - Auger drive

Motor: 3-phase Dahlander
- Manufacturer: Baumüller Nürnberg
- Power: 1.1 / 2.2 kW
- Speeds: 460 / 920 rpm
- Voltage: 380 V
- Frequency: 50 Hz
Resulting speeds: auger ~73 rpm
Sprockets: z12 → z76
Shafts: 32 mm motor, 40 mm auger
Chain: 10B-1

Motor and auger drive

Controls & Wiring

Contactor cabinet
- Devices: 6 contactors, 2 time-delay relays
- Functions: Dahlander 2-speed (scraper), auto-reverse auger (0–1 s adjustable), interlocks & timeouts
- UI: Main power switch, latching power toggle, 2 indicator lights
UI box
- Controls: Run (auger), AUTO/MAN (scraper), scraper speed
Wiring
- Motors:
  - 7G0.75 mm² for scraper (Dahlander)
  - CEE 16 A outlet for auger motor
- Supply: CEE 16 A, 5×2.5 mm²
- UI harness: 9×0.5 mm² to rear UI box

Contactor cabinet (mounted)

UI box at the outlet: scraper speed, scraper mode, start

Planning

This project was modeled in CAD first.
A simplified trailer model with only the relevant features and an exact attachment design was created.
This made it possible to try different arrangements and positions, check clearances and mounts, and settle the layout before building.

sanity-check of auger rpm:

Technical Assets

Part drawings

Only the parts that benefited from exact dimensions were built from CAD drawings; the rest were straightforward workshop parts built directly from the model and measurements.

Assembly overview

Driveshaft detail

Drivetrain calculation

A small spreadsheet was used to try different motor/ratio/chain options with available and bought parts, the final choices are highlighted.

Electrical schematic

Features

Emergency stop (cut all power)
Main power switch (supply isolation)
Indicator lamps: Turned ON / Enabled, Disabled / Fault
Auger control: forward run, reverse-current braking (plugging) with adjustable timer
Interlocks: electrical + mechanical FW/REV; Dahlander bridge/line
Scraper control: AUTO / MAN selector
Dahlander speed-select (scraper): bridge → line