The standard bushes also fit directly to the T3, T4 and T5 models, giving compatibility across the entire range. When we come to guide-bush work with home-made jigs and templates we have to consider two factors which do not arise with commercial devices: Making simple jigs and templates for use with guide bushes has a spectacular effect on bringing your router to life and opening up possibilities of creative work.

Examples include the Bosch GOF 2000 ACE, the new Festool OF 2200 EB, the Hitachi M12 V2 and the Triton TRA001 2000. A bonus with both these plates is that they come with a centring bush and pin so you can ensure concentricity with the motor spindle. Some of the non-Trend routers that accept Trend guide bushes Generally speaking, fitting a guide bush to your router reduces the efficiency of the dust extraction. The exceptions are those few routers designed with dust extraction as a priority and guide bushes that support good extraction. The best examples, in my experience, are the De Walt DW 621 and the Festool 1400 and 2200 models, with their built-in dust extraction and guide bushes designed in skeleton form. Tip. When you have located the fixing holes the first time you fit the Unibase, mark them with a dab of paint to speed the process on future occasions. Whenever I acquire a commercial jig I make a mounting board for it and I make it so that it looks as if it is designed for the jig in question. I cut handholds for carrying and hanging the jig, and I put a decorative moulding on the edges of the board and the handholds, with a bearing-guided cutter.Most guide bushes are fitted to the router base by means of two 5mm machine screws in threaded holes in the base casting. With some models, however, and not only the cheaper ones, fixing is by means of nuts and bolts through plain holes or by screwing into threaded inserts in the plastic dust extractor spout. This can lead to non-concentricity in the bush, make it difficult to tighten the collet nut, and seriously increases the time and effort involved in fitting and removing guide bushes. This, in turn, discourages the more creative uses where cuts are positioned and repositioned by changing the guide bush, the cutter, or both. Thus with a guide bush of 20mm diameter and a cutter of 10mm diameter the offset is ½(20 – 10) = 5mm. Regrettably, there is no standard size or fitting for guide bushes. The widest range by far is the Elu/ De Walt/Trend system, with a 60mm diameter plate attached to the router base with two 5mm countersunk screws. Most commercial jigs (whoever they are made by) come with a Trend-compatible bush as standard. They fit not only most routers from Elu, De Walt and Trend but also a number of other popular models. If your router does not accept these bushes, and does not include a bush of the required diameter in its own range, you have to make or buy an adaptor plate to take them. Trend offer two such plates: the Trend Unibase and the more expensive Circular Sub-base.

If you plan to do much guide-bush work with MDF or one of the irritant hardwoods, you would do well to consider the dust extraction question very seriously. Most guide bushes are of steel construction but Trend offer three boxed sets of plastic bushes. Set 1 is metric in even sizes from 10mm to 32mm, Set 2 is in odd sizes from 11mm to 33mm, and Set 3 is in Imperial sizes from 3/8in to 1 5/16in. These sets offer an economical way of acquiring guide bushes; if you find yourself constantly using a particular size you can buy the steel version. Whether the template has to be made that much larger, or that much smaller, than the final product depends on whether the template is an ‘inside’ one or an ‘outside’ one. With an inside template the cut is smaller than the template but with an outside cut the cut is larger than the template. The subject is a large one and in this article I deal with the basics. In subsequent articles I will expand on guide bush applications and the making of templates.

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With the hand-holds completed, they and the board’s edges are decorated with a 1/4in radius bearing-guided ovolo cutter. A selection of home-made jigs and templates with their guide bushes The cut takes place at a distance from the edge of the template. This distance, called the ‘offset’, depends on the combination of cutter diameter and guide bush diameter and has to be allowed for when making a template. It is calculated as follows: ½(outside diameter of guide bush – diameter of cutter). The standard 60mm Trend bushes also fit a number of other medium-power routers, although their manufacturers tend not to publicise this point. Trend routers with a selection of their guide bushes See in our online shop the Trend Unibase and the Trend Circular Sub-Base) The Trend circular sub-base fitted to the DW 625 router