Trend DC400 an independent review by John Bullar

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Independent Review of theTrend DC400 Dovetail Jig

© John Bullar 2003

previously published in Furniture & Cabinetmaking magazine

Trend call their new DC400 a multifunctional dovetail centre and it certainly seems to have more functions up its sleeve than your average jig. As well as through and lapped dovetails, both with variable spacing, you can cut skewed joints, shadow joints, rebates and more according to the suppliers. But it also costs a fair bit extra compared with previous Trend offerings, so what do you get for your money? To start with the manual (and I certainly needed to start with the manual !) it is excellent, a clearly written well-illustrated spiral bound handbook. After the initial set-up it gives a simple overview of each joint then takes you step by step though the procedure to make it. While it takes you logically through every stage, if you want to hop between sections that is no problem either. The DC400 is manufactured to tight tolerances in imperial dimensions. The preliminary manual I was given used fractions of inches. I presume it will be metricated for the European market, which may lead to some odd sizes of decimal point millimetres being quoted to avoid loosing accuracy.

The body of the jig is a chunky, box-shaped vice. Made from steel and alloy it is reassuringly heavy in smart black and silver. It contains horizontal and vertical clamps with left and right hand drives, geared together for an impressively smooth parallel action. The clamp faces have a gritty surface to give a firm grip with moderate pressure. A single twist-knob fits each drive and removes for unobstructed working. But it is slow, I cant help feeling a crank handle would have been better. With the optional waste collector fitted, the body acts as an efficient dust collection chamber with a removable clear front window. Fittings are provided for a dust extractor or vacuum cleaner hose.

Above the clamps is a metal guide rail to which you clip individual pin and tail guides. The guide rail has a series of fine indexing holes along its length to locate the guides in incremental positions. These let you choose the spacing for a dovetail pattern. The guides themselves are neatly made from hard plastic with tiny little integral clips moulded into them. These clips are used to secure the guides on the rail. The guides were initially quite stiff to fit and I accidentally managed to snap one of the clips in my fumbling about. It is necessary to swap guides each time you go from pins to tails and vice-versa, so these clips will see a lot of action in a busy workshop. I could see the guides becoming a bit of a consumable item and think it would be necessary to keep some spare guides in case of breakages. Once locked in place the guides were very secure (even including the one I broke).

A steel cable support post comes as standard, it needed a bit of bending to secure the router cable. I was keen to get stuck in with the DC400 so it was a little frustrating to find that before doing anything else you need to: find yourself a sheet of plywood or MDF, cut and drill it as a baseboard, screw it to the jig body then find some G clamps and fix it to your bench. I would have thought the jig's end castings could easily have been supplied with lugs for the purpose - or better still if the jig came complete with its own clamps. Having said that, once the body was clamped down it made a rock-solid support for a heavy router. Trend recommend using a medium to heavy-duty router with the DC400 so I used the Makita 3612C - a 1.8kWatt beast weighing in at 6 kg. The jig was supplied with an 11.1mm (7/16 inch) template-following collar of the Trend mount variety, which did not fit the Makita. The Trend Unibase is an optional extra to get you around this - a perforated shoe to fit Trend accessories on the base of most other routers, but it is a bit awkward. If I were using the DC400 much I would obtain the right collar to fit the router.

Working through the instructions you start by making lapped-dovetail joints then move on to through-dovetails.
As with any jointing technique you have to prepare good, straight, square ends on the timber. To avoid splintering you have to push the router very slowly through the wood because a dovetail cutter has to work at full depth. Despite my care the first 'joint' I attempted was a spectacular failure! After moments of panic and despair I realised that you can only cut lapped dovetails if the thickness of the pin piece is more than the length of the dovetail cutter. If like me you do not insert the full length of the cutter in the wood you end up with a really, sloppy joint. But it was all there in the manual if only I had taken the trouble to read it properly! What this mean though is that the standard 7 cutter supplied with the jig is only suitable for cutting pins in thick timber.

For thinner stock you need to get the optional cutters. These produce shorter pins of the same width (11.3 mm ) and a choice of greater angles. After playing around with the depth setting and slowing down the feed rate to avoid tear-out some decent lapped joints emerged. I moved on to try through-dovetails. This time a straight cutter ( 8.0 mm) is used for the pins; the guides supply the angle. My first joint in pine went straight together with a tight fit - tight enough to split its sides! Variable spacing came to the rescue and I moved the guides inwards to a pitch that better suited the timber. All went well the second time with the aid of a mallet to close the joint. By now I was growing to like the DC400 so I offered it some knotty English oak to cut through-dovetails in.

With the jig being such a solid construction there is no noticeable vibration even on hardwood so it cuts very sharp precise edges. It made the joints in this wild-grained oak very clear cut and business-like. But would these pretty oak joints fit together? Would they heck! While the soft pine had squeezed itself into compliance this oak joint was not having any of it. Unlike with lapped dovetails where you simply alter the depth to adjust the fit, according the manual the only way to deal with tight through joints like this is to obtain the optional 8.1 mm 'oversize' cutter to make the tails slimmer. I did not have one, so instead I decided to cast off the Unibase with its 11.1 mm collar then fit a standard 11 mm Makita collar directly on my router. This did the trick. It allowed me to repeat the pin cutting and shave that all-important 0.1 mm off each side. The resulting joints in oak were a treat as I knocked them together. I was so taken with the way the DC400 cut through-dovetails in oak that I just kept going with it and found myself making an oak jewellery case

The DC400 can help you to cut some pretty fine and varied joints - by the end of the test I was really enjoying using it. If you are thinking of buying one you will probably soon want some of the optional extras to deal with a range of timber thickness and types. The dust extraction option works well, which is important for health. The brittle clips on the guides worried me - maybe in time the designers will have another look at these components. Clear instructions are essential for using a novel design of tool and these ones will propel you up the learning curve. If all tools came with a manual of this quality the world would be a finer place. If you want the functionality and you are prepared to pay for it the DC400 multifunctional dovetail centre is a solid platform to build on.

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Independent Review of theTrend DC400 Dovetail Jig © John Bullar 2003 previously published in Furniture & Cabinetmaking magazine
Trend call their new DC400 a multifunctional dovetail centre and it certainly seems to have more functions up its sleeve than your average jig. As well as through and lapped dovetails, both with variable spacing, you can cut skewed joints, shadow joints, rebates and more according to the suppliers. But it also costs a fair bit extra compared with previous Trend offerings, so what do you get for your money? To start with the manual (and I certainly needed to start with the manual !) it is excellent, a clearly written well-illustrated spiral bound handbook. After the initial set-up it gives a simple overview of each joint then takes you step by step though the procedure to make it. While it takes you logically through every stage, if you want to hop between sections that is no problem either. The DC400 is manufactured to tight tolerances in imperial dimensions. The preliminary manual I was given used fractions of inches. I presume it will be metricated for the European market, which may lead to some odd sizes of decimal point millimetres being quoted to avoid loosing accuracy.
	The body of the jig is a chunky, box-shaped vice. Made from steel and alloy it is reassuringly heavy in smart black and silver. It contains horizontal and vertical clamps with left and right hand drives, geared together for an impressively smooth parallel action. The clamp faces have a gritty surface to give a firm grip with moderate pressure. A single twist-knob fits each drive and removes for unobstructed working. But it is slow, I cant help feeling a crank handle would have been better. With the optional waste collector fitted, the body acts as an efficient dust collection chamber with a removable clear front window. Fittings are provided for a dust extractor or vacuum cleaner hose.
Above the clamps is a metal guide rail to which you clip individual pin and tail guides. The guide rail has a series of fine indexing holes along its length to locate the guides in incremental positions. These let you choose the spacing for a dovetail pattern. The guides themselves are neatly made from hard plastic with tiny little integral clips moulded into them. These clips are used to secure the guides on the rail. The guides were initially quite stiff to fit and I accidentally managed to snap one of the clips in my fumbling about. It is necessary to swap guides each time you go from pins to tails and vice-versa, so these clips will see a lot of action in a busy workshop. I could see the guides becoming a bit of a consumable item and think it would be necessary to keep some spare guides in case of breakages. Once locked in place the guides were very secure (even including the one I broke).
	A steel cable support post comes as standard, it needed a bit of bending to secure the router cable. I was keen to get stuck in with the DC400 so it was a little frustrating to find that before doing anything else you need to: find yourself a sheet of plywood or MDF, cut and drill it as a baseboard, screw it to the jig body then find some G clamps and fix it to your bench. I would have thought the jig's end castings could easily have been supplied with lugs for the purpose - or better still if the jig came complete with its own clamps. Having said that, once the body was clamped down it made a rock-solid support for a heavy router. Trend recommend using a medium to heavy-duty router with the DC400 so I used the Makita 3612C - a 1.8kWatt beast weighing in at 6 kg. The jig was supplied with an 11.1mm (7/16 inch) template-following collar of the Trend mount variety, which did not fit the Makita. The Trend Unibase is an optional extra to get you around this - a perforated shoe to fit Trend accessories on the base of most other routers, but it is a bit awkward. If I were using the DC400 much I would obtain the right collar to fit the router.
Working through the instructions you start by making lapped-dovetail joints then move on to through-dovetails. As with any jointing technique you have to prepare good, straight, square ends on the timber. To avoid splintering you have to push the router very slowly through the wood because a dovetail cutter has to work at full depth. Despite my care the first 'joint' I attempted was a spectacular failure! After moments of panic and despair I realised that you can only cut lapped dovetails if the thickness of the pin piece is more than the length of the dovetail cutter. If like me you do not insert the full length of the cutter in the wood you end up with a really, sloppy joint. But it was all there in the manual if only I had taken the trouble to read it properly! What this mean though is that the standard 7 cutter supplied with the jig is only suitable for cutting pins in thick timber.
	For thinner stock you need to get the optional cutters. These produce shorter pins of the same width (11.3 mm ) and a choice of greater angles. After playing around with the depth setting and slowing down the feed rate to avoid tear-out some decent lapped joints emerged. I moved on to try through-dovetails. This time a straight cutter ( 8.0 mm) is used for the pins; the guides supply the angle. My first joint in pine went straight together with a tight fit - tight enough to split its sides! Variable spacing came to the rescue and I moved the guides inwards to a pitch that better suited the timber. All went well the second time with the aid of a mallet to close the joint. By now I was growing to like the DC400 so I offered it some knotty English oak to cut through-dovetails in.
With the jig being such a solid construction there is no noticeable vibration even on hardwood so it cuts very sharp precise edges. It made the joints in this wild-grained oak very clear cut and business-like. But would these pretty oak joints fit together? Would they heck! While the soft pine had squeezed itself into compliance this oak joint was not having any of it. Unlike with lapped dovetails where you simply alter the depth to adjust the fit, according the manual the only way to deal with tight through joints like this is to obtain the optional 8.1 mm 'oversize' cutter to make the tails slimmer. I did not have one, so instead I decided to cast off the Unibase with its 11.1 mm collar then fit a standard 11 mm Makita collar directly on my router. This did the trick. It allowed me to repeat the pin cutting and shave that all-important 0.1 mm off each side. The resulting joints in oak were a treat as I knocked them together. I was so taken with the way the DC400 cut through-dovetails in oak that I just kept going with it and found myself making an oak jewellery case
	The DC400 can help you to cut some pretty fine and varied joints - by the end of the test I was really enjoying using it. If you are thinking of buying one you will probably soon want some of the optional extras to deal with a range of timber thickness and types. The dust extraction option works well, which is important for health. The brittle clips on the guides worried me - maybe in time the designers will have another look at these components. Clear instructions are essential for using a novel design of tool and these ones will propel you up the learning curve. If all tools came with a manual of this quality the world would be a finer place. If you want the functionality and you are prepared to pay for it the DC400 multifunctional dovetail centre is a solid platform to build on.