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The previous channel versions used a square U-shaped plastic strip fixed into the carriage and which ran in the grooves in the channel. The fit of the plastic into the grooves has to be a compromise between no play and smooth running. There was always a little play or "rattle" in the carriage which normally could be taken out by pulling forward when locking the work against the fences. Numerous anti-rattle devices have been made by users. Secondly a thin strip of wood or plastic could be inserted into the plastic strip to stiffen it up. In his new design Martin has opted to have an alloy tongue set in the centre of the carriage groove over which the plastic runners sit. In theory the tongue will stop any torsion in the runners and dramatically reduce rattle. This is no mean feat in the extrusion process and these little tongues are superbly made. However, I am very disappointed to find that currently the "rattle" is worse than before. I accept that these plastic strips are difficult to mould but more work needs to be done to gain a better fit. In my WoodRat this is exasperated by the fact the the Channel grooves are of different sizes. The lower one is wider than the top one leading to a slight tilt when the carriage is pulled forward to remove any play. In normal WoodRat operations this is not really noticeable or of real concern as the work/fence combination ensures parallel clamping however when the MR3 mortise rail is used tilting and run out do have consequences. More on that in another report. |
| The upper groove measures 5.32 mm and is equal along the length of
the channel. This caliper is the new 6 inch version supplied by www.chipsfly.com.
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The lower groove is 5.68mm wide and larger than at the top. |
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This view shows how the plastic moulding sits and locks onto serrations on the alloy tongue. This is the lower carriage strip. Note the gap between channel and plastic. I would like to see a square section strip that fully filled the groove and be happy to lightly sand down any over sized plastic to get a good fit. The earlier version did give some lee-way to pack it out but I can't see any way to adjust this. As the base of the plastic wears then up and down movement will increase. There was a degree of compensation in the earlier version by lightly prising the plastic runner up but this later one is trapped by the serrations. |
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This is the upper plastic strip which also has a gap although less than the lower one . I accept that the fences will reduce some of the "rattle" but this is just too much. Yes, I have tried the old plastic strips and they don't fit at all.
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| I also found the moulding to be variable in cross-section. Here it is 5.06mm to fill a 5.32mm groove. |
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Here it is 4.94mm which is pretty slack in a 5.68mm groove. |
Conclusion
As a long time 'Rat enthusiast I have been looking forward to using this revision. I have not had time to really test it in earnest and will report on that later. My overall impressions are very favourable with some reservations as I feel sure all the extra T-slots will prove to be very useful. The anodising quality I would prefer to be better but can live with it as the poor bits are out of sight and the visible parts excellent. Clearly a lot of thought has gone into the re-design and once the bugs are out should prove to be very worthwhile. Cleaning up and countersinking the holes is not expensive or time consuming and must surely be part of the pre-packing and inspecting procedure.
The excessive "rattle" after all the effort that Martin has placed into the revision must be particularly irksome to him and is a real disappointment to me. Perhaps I am being overcritical as in normal use the machine is very usable. In conjunction with the MR3 mortise rail I have had problems which can be fixed with a simple anti-rattle device.
I have since had some discussion with Martin and he is awaiting delivery of some updated and improved plastic runners. These are difficult to make and moulds are expensive. When they are available I hope he sends me some so that I can report back. The different sized grooves are not a design feature but perhaps caused during the extrusion process. That again would be a hugely expensive jig re-work. One solution would be to have different sized plastic runners.
I am not entirely happy, he must be as mad as hell!
Having experienced superb quality and attention to detail on my first WoodRat I suspect that perhaps I have just been unlucky and got a rare "Friday afternoon" model. Even so, I still highly recommend this version with the proviso that Martin can quickly resolve the plastic runner issue.
If you are the owner of one of these revised WoodRats then I would love to hear from you. Email me here
Update 1 I have now received some email feedback and it would appear that others have been satisfied with the anodising and the finish of the holes has been just fine.
Update 2 The "rattle" issue. Over the years I have experimented with various carriage runner replacements and know only too well the difficulties and the fine line between too tight and too loose. Since design and cost constraints will always be there I have concluded that for certain operations simple anti-rattle gadgets are the best way forward. I have a suspicion that Martin has been rather cunning in providing the extra T-slots that should enable users to make them plus other jigs. I am really looking forward to a rash of new ideas.
