Test: Allen Custom Drills C-D 4000

Brent Lilley heads to the Maniototo Basin in Central Otago to test the Allen Custom Drills C-D 4000, a seed drill that's proving its worth in the toughest conditions.

The C-D 4000 drill is a four-metre, triple-disc drill, built by Ashburton-based Allen Custom Drills and owned by Maniototo Contracting, which operates from Ranfurly and provides a full range of contracting services in Central Otago.

Owner Ian Hore purchased the drill in September last year to replace an older Duncan Enviro drill, and since then it has clocked up over 2000ha, with operator Ricky Patterson at the wheel for much of the time. Both were pretty keen to showcase the drill and had few negative things to say about it.


At the front of the drill is a two-point linkage hitch arrangement on the lower arms of the tractor, allowing for plenty of movement in all directions on undulating terrain and tighter turns than a conventional drawbar on the headlands. Cat 3 pins are used in extra-wide openings for the plough arms that will also accommodate the larger American-style quick-hitch.

Allen Custom Drills believes you need plenty of weight in a drill to keep the openers in the ground, so you might as well build the machine heavy from the start. This shows throughout, with hefty nine-millimetre thick box section beams making up the chassis of the drill, and heavy-duty plates and gussets used to strengthen every join and any other conceivable weak spot.

To obtain a working width of four metres, two folding wings are used each side of the central section. These are as well built as the chassis itself, with heavy-duty hydraulic rams to fold them. Guide wheels on the outsides of the wings help them to follow the contours of the ground independently.


A large hopper is mounted down the centre of the machine, split into two bins — one 800-litre bin for seed; and a 1300-litre bin for fertiliser, able to take around two half-tonne bags. A dust- and rain-proof tarpaulin cover rolls clear of the top of the bins, while a ladder from the left-hand side to the platform gives access for the operator.

Inside the hopper, removable steel mesh prevents larger objects from entering the metering mechanism, and an adjustable level sensor is located low under the mesh to allow drilling to continue down to a very low level, before letting the operator know the bin is nearly empty.

Allen _Custom _Drills _1


While it might seem a little excessive to have a crane mounted on the side of the drill, the owner and operator both maintained this was pretty much the greatest thing since sliced bread. It can lift around a tonne and they’ve found it’s able to reach over fence lines and into sheds to retrieve half-tonne bags of seed and fertiliser without having to rely on other machines to help load the drill.


A fan mounted out of dust’s reach, at the front of the machine, is hydraulically driven directly through the remote valve on the tractor, so the speed can be changed by adjusting the oil flow out of the tractor. The fan speed is displayed on the monitor, making it easy to set and keep an eye on.

Bolted onto the side of the fan is a heat exchanger, which serves two purposes: firstly, it keeps the oil driving the fan cool, to prevent the back end of the tractor overheating; and secondly, the warm air drawn into the fan keeps the seed and fertiliser hoses on the drill dry, preventing blockages.

Metering and calibration

Allen Custom Drills has used Accord metering units, which can deliver seed rates from one kilo per hectare to 400 kilos per hectare. Maniototo Contracting has tested this range, sowing swedes several times, at around one kilo per hectare and cereals over 300 kilos per hectare, and can confirm the metering proved accurate and reliable.

This metering system is combined with electronic drive, a ground-speed radar, and the RDS Artemis monitor in the cab, which makes calibration incredibly straightforward.


The Allen C-D 4000 uses a triple-disc setup, and its overall heavy nature to ensure good ground penetration. Up front, the leading turbo discs are individually mounted on a proven rubber Dura-torque system in two rows under the hefty box section beam.

Following these are two plain discs set in a ‘V’ formation on each coulter to open up a slot. Seed and fertiliser are fed out of separate hoses to ensure accurate placement and are dropped between the two discs. Finally, a press wheel closes the slot and firms the soil around the seed for improved germination.

Coulters mount to the frame via a parallel linkage setup that allows each one to move independently while maintaining a constant down pressure. An adjustable spring in this linkage also allows for the downforce on each coulter to be varied from 70 kilos to as low as 50 kilos in soft, cultivated soil.

A clever setup allows the sowing depth to be adjusted in three sections, rather than on each coulter. A minor complaint here would be the lack of a scale on this adjuster, which would make it easier to return to a previous setting.

Allen _Custom _Drills _3

The verdict

I’m a big fan of New Zealand-based equipment manufacturers, but I’m an even bigger fan when the machinery can hold its own against international models — and that is exactly my opinion of Allen Custom Drills equipment.

It is built like a tank, which is important here in New Zealand. And the hefty build quality also comes in handy, adding much-needed weight to keep the openers in the ground in dry conditions.

Overall, this is a great simple machine to operate. It’s built to last in even the harshest conditions and I, for one, am keen to see more of the Allen lineup in the future.

Thumbs up

  • Extremely well-built, heavy-duty chassis
  • Triple-disc and packer wheel setup creates tilth and ensures adequate seed soil contact 
  • Electronic drive with ground-speed radar and monitoring 
  • Large split bin hopper to carry seed and fertiliser 
  • Hiab crane for self-loading of the drill 
  • Large flotation tyres for safe, stable road transport
  • Sectional sowing depth adjustment eliminates the need to alter individual coulters

Thumbs down

  • Sowing depth adjusters could do with a scale to make it easier to return to previous settings

For the full, unabridged test, check out the August 2014 issue (#208). Subscribe to Farm Trader magazine here.

Previous ArticleNext Article
Send this to a friend