Cockpit Gratings - We need a smaller (!) boat ...

 ... or bigger gratings!

("We need a bigger boat", a reference to the film "Jaws", is a standing joke amongst the Pagan crew)

So having finished the router table setup, it was time to try it out on some relatively cheap pine board I had lying around.

The first thing I discovered was that it's easier to work from behind the carriage and push than the more obvious option of standing in front and pulling. 

The second thing I quickly discovered is that my cunning plan of routing the slots in the full width of the boards before ripping them lengthwise into individual rails doesn't work very well.

The problem is that the additional drag of the wide board over the bed of the router table makes it difficult to keep the carriage running true even with our cunning ball race track setup. On two out of three attempts, there was a wiggle part way through. I'm sure it could be made to work with further development and engineering (some means of keeping the runners from lifting up and twisting would be needed) however there's not a lot of advantage over routing the rails individually. It takes a bit longer but not enough to make spending any more time or money on the jig engineering worthwhile.

Ripping the rails out of the board, having cut off the failed slots, took minutes on the table saw and then I set about routing the slots into them. That takes a while and didn't do my back much good - I think I'll look at mounting the jig higher so I'm not having to bend over so much. Bearing in mind that cheap pine board is prone to chipping, the routing went extremely well and cleanly. 

I cut the rails I'd routed in half and did a dry fit. The interlocking rails took some gentle persuasion to go together but the fit wasn't too shabby.

The second dry run, after I'd spent a bit of time cleaning up the slots with a file, went much better and I then set about glueing up a test grating.

Some lessons were learnt along the way such as don't trim the excess off the rails until after glue up (really not sure where my head was at when I did that! I hadn't intended to do it that way round and it made things harder than they needed to be).

I also took note of the need to mark up the order and orientation of the rails during the dry fit more thoroughly than I did on the prototype.

And I think I need to lay in some slow setting wood glue, not an easy thing to find, as the readily available stuff all sets up in under ten minutes. Often that's a big advantage but on this job, when I get on to the full size gratings, I need plenty of time to get everything in place and clamped up.

Oh and clamping the full size gratings is going to present some challenges which I'm pondering.

Once the glue had set up, I hit the top surface and sides with the belt sander and then finished with a finer grit on the palm sander.

I'm pretty damn pleased with the end result!

It's not perfect, there's a few careless dings and I split out a bit on one of the rails on the backside. I also either need some sort of jig to hold the belt sander square ... or to hole the piece square to the belt sander ... when doing the edges. Either that or a bench mounted sander with mitre table (which is on my shopping list anyway).

That said, the fit and finish is considerably better than the factory made originals I'm replacing!

Another proof that prototyping is never a bad thing ... I realised I need to make the gratings up slightly thicker than the final finished thickness (18mm) to give me a decent amount of sanding allowance. The rough sawn boards are nominally 25mm and the usual planing allowance is 3mm per face which would result in 19mm. I think a 1mm sanding allowance would be about perfect so I need to tweak my cutting instructions to remind me to leave 1mm sanding allowance when I'm thicknessing the boards.

Anyway, if the finished gratings are as good as the prototype, I'll be a happy wood butcher. And I'm sure I can do better next time around with the benefit of experience gained.

There's probably going to be a bit of a hiatus on this project now. I've got other things to do over the next couple of weeks and then we've got over a fortnight on board Pagan at the end of the month when hopefully we'll get to go sailing before putting Pagan to bed for the winter.

Cockpit Gratings - router jig development

 Full disclosure ... there's absolutely nothing boaty below! There's also a lot of images

Anyway, one of the challenges of making  new gratings is the considerable number of halving joints that have to be cut in the rails. If each one was cut by hand the traditional way (saw and chisel), it would take a LOT of time 'cos there's no less than 696 of them on the gratings for Pagan!

Confucious he say that if the Gods had intended man to faff about cutting 696 halving joints the hard way, he wouldn't have invented power tools! Even so, it's not as simple as it seems. Each joint needs to be 22mm wide by 9mm deep and spaced on 44mm centres from the adjacent joints. The margin for error is small by woodworking standard - the longest rail is 508mm long and a 1mm error between joints would add up to being 15mm out at the middle (assuming, as I intend to do) starting from the ends to the middle. Needs to be a lot better than that.

I considered various methods...

Our American friends would tool up their table saw with a dado cutter set but they're not available in the UK and Europe because they're considered dangerous (and with good reason as to use them you have to remove the riving knife that prevents the workpiece closing up and grabbing the blade with potentially lethal consquences). That's a none starter then.

I contemplated and sletched designs for clamping the workpiece in a jig with a guide bar setup to use a hand held router with a 22mm cutter to cut the joints. That would have worked well enough I'm sure but then I came up with the notion of turning things on their head and fixing the router whilst moving the workpiece. In theory, that ought to be the simpler solution (in practice, I'm not sure that the first idea wouldn't, in the end, have been easier but hey ho).

So I sketched up a design for a very simple jig  ...

And built it ...

The base is two layers of 9mm MDF, the carriage is made of the same stuff. Underneath is mounted a fairly hefty router donated by my brother who no longer had a use for it.

(There's numerous videos on YouTube of similar jigs and there's off the shelf parts for building them at various levels of sophistication right up to the next best thing to a full spindle moulder setup. however they invariably use trim routers. Iroko, from which the new gratings will be made, is tough stuff and hard on cutting edges so I needed a powerful heavy duty router as the basis for the jig).

It sort of worked. Conceptually, it prooved I was on the right lines. However, it proved impossible to repeatedly keep the carriage tracking at 90 degrees to the router cutter head. I also found that trying to rout a halving joint at the end of a workpiece inevitably led to tear out. There were some other niggles too all of which added up to a case of back to the drawing board to come up with Mk.II

There's quite a lot to unpack here!

First significant change is the use of several 3d printed parts. My brother adapted a design he already had on file for ball bearing track guides as a solution to keeping the carriage square when using the jig. 

I also designed, and Glen 3d printed, a stop bar large enough to accomodate the full width of the Iroko boards. Based on test cuts with the Mk.I jig, I had concluded that it would be faster and more accurate to cut the halving joints into the boards before ripping them down into the individual rails.

I also reworked my cutting plan so that each rail is initially made 44mm too long with the excess to be cut off after the gratings are assembled. That avoids the problem of tearout when trying to run a cut at the end of the workpiece (at the cost of wasted timber but hey ho).

So having a design, and after a trip to Bodgit & Quit for more MDF, I set to making the thing ...

Step 1: Cut the two base plate pieces from a sheet of 9mm MDF

Steps 2 & 3: Cut the track slots and router bit clearance holes in the top plate

Step 4: Mark out and cut the recess for the router show in the bottom plate

Step 5: Glue the top and bottom plates together

Step 6: Mark the mounting holes for the router (bizarrely, only 3 of the 4 pre-drilled holes in the router shoe can be used as the 4th hole is fouled by the depth stop anvil)

Step 7. The holes were then countersunk on the top side of the base plate

Step 8: Mount the router and clamp the base plate in the old Workmate that will be used as as stand for the jig when in use.

(When not in use, the jig will be stored out of the way on a shelf).

Step 9: Cut the pieces for the carriage and step 10: glue them together ensuring they are accurately clamped at 90 degrees (the Mk.1 prototype was a bit of a failure at this stage. The Mk.II is as close to spot on as I'm likely to get!)

Step 11: Cut some reinfocing pieces and step 11; glue them in place

Step 12: Carefully measure, mark and fit the upper ball race rails 3d printed by my brother Glen.

It was vital at this stage that the rails were as close to parallel to each other as humanly possible. Measure many many times, screw down once!

Step 13: Fit the lower ball race rails with the same level of care and attention.

The rails were designed with slotted mountings to allow the positioning to be tweaked as necessary.  As it happens, it was barely neccessary and the carriage glides very nicely backwards and forwards without any racking or twisting

At this point, I realised I'd dropped a bit of a clanger and made the base too small to be able to easily clamp it or the carriage to the Workmate

Easily solved ... I made up two pieces of MDF per side glued together and then ...

... glued them to the base.

That gives me the option to clamp the base to the Workmate (although it seems to clamp well enough on the router shoe) and also to clamp the carriage in place in order to use the jig for other purposes.

At this point I did some test cuts into scrap wood and it was fortunate I did so as I swapped which side of the cutter the guide bar is set (the rotation of the cutter tends to throw the workpiece to the left so having the stop bar on that side prevents that)

The tricky bit now was routing out the mounting slot for the aforementioned stop bar. It needed to be as close to a 44mm offset as possible. Although a certain amount of adjustment is built in to the design, the closer the better to start with.

The trick here was to stick some masking tape onto the base and then superglue down some spare lengths of track carefully at the right spacing ...

... then the carriage could be run on the temporary tracks with the router cutter set to the correct height to cut the slot for the stop bar.

Cutter clearance slot on the left, stop bar slot on the right

Along the way, I'd routed a slot for an adjustable 3d printed hold down clamp (I forgot to take an photos, you'll be relieved to read!).

I also decided I needed to put in a couple of cutouts in the front face of the carriage to make it easier to hold the workpiece in place.

A template was cut out of MDF and temporarily fixed in place using the tape and superglue trick. My own router fitted with a guide wheel cutter then made short work of cutting out the hand holds.

The hand hold routed out and the template after being peeled off

Test cut time!

You can better see the hold down clamp in action and I've just cut the second slot using the stop bar in the first slot I cut

Measuring up, the spacing is spot on.

However, I'd failed to consider that the carriage is held slightly clear of the base plate by the ball races and that necessitated a reprint of the stop bar with the projection thinned down to 6mm instead of 9mm.

I also found that the wood screws securing the stop bar weren't gripping ...

The solution to that problem was to use M4 T nuts. In softwood, they'll bit in and end up flush with the surface of the wood but MDF isn't very compressible to I cut a shallow recess using a Forstner bit to make sure they'd be flush

And the finished router table in all it's glory!

The next step is to run some test cuts and, if necessary, adjust the stop bar to reduce the cumulative spacing errors to an acceptable level (assuming it's not already OK).

I'll experiment with taking some video of it in action but no promises on that front!

The end result has taken a fair bit longer, and cost somewhat more (about £40 not including the router and cutter) then I expected but having made it larger and more sophisticated than stricty necessary it will have a life beyond this one project.

That was the week (and a half) that was

 So having got Pagan back in her element and finding that, as half expected, one or more head bolts had failed to torque down, what happened next?

Simon rocked up on Saturday and we set about dealing with the stripped head bolt thread and it's partner in crime opposite. Although the second bolt had gone down to torque, two out of three of the bolts across the head at the aft end of the engine had now stripped (the centre bolt having already been helicoiled when we first rebuilt the engine) and we decided not to take any chances and do both of the outer bolts.

That was all done in an afternoon and everything put back together again. There's still a few outstanding periperhal jobs, the main ones being fitting a new and relocated engine stop cable and fitting a cooling system header tank and plumbing in the calorifier. These can, however, wait until later possibly even until the winter. We also have a low speed timing issue on the engine, which we suspect is long standing, which again isn't an immediate attention job as at normal running speeds the timing is fine. It won't do the engine any harm as long as we don't trundle around at below 1500rpm for hours on end and I can't imagine we'd ever do that.

Jane and I were then on a mission to turn Pagan inside out and put her back to being a cruising yacht instead of a caravan / workshop. During the course of that excercise, we'd determined that not only were our domestic batteries fried, so was the two or three year old engine battery. It wasn't taking or holding a charge and I've reached the conclusion that before it committed suicide, our defunct battery charger had taken out the domestic and engine batteries.

That meant a trip to Chelmsford to pick up a new No.1 (Engine) Battery from Halfords.I chose a reasonably priced 95a/h sealed lead acid battery, larger than really needed for the No.1 battery but it'll have to do double duty as I won't be fitting new domestic batteries until over the winter (we need more capacity than we can squeeze into the existing battery compartment and that means a new battery box in the port cockpit locker which isn't a quick job to create).

Finally, by Tuesday, we were ready to let go from the pontoon and go for a blat up and down the river within sight of the moorings. A good solid hour plus of zooming up and down and I was a very happy chappy.

We picked up our mooring on the second attempt and picked up where we'd left off on the immediate to-do list. The principal job now was sorting out the running rigging, bending on the sails and fitting the new sail covers.

She does look shipshape and seamanlike now she's sporting her full rig again!

That said, all of the running rigging needs to come off over the winter and be thoroughly cleaned. I don't think we need to replace anything, all the lines are sound, but it's all grungy and stiff.

The big test came on Saturday ...

Could we make it to Burnham-on-Crouch without breaking down?

Yes we could!

We probably got some funny looks motoring downriver when the sailing conditions were near perfect but this was an engine test run not a jolly. And she performed flawlessly finishing off with just about the nearest thing to a perfect marina docking manoeuvre we've ever managed.

We met up with Simon at The Old White Hart for a meal and beer where we were joined for drinks by our good friends Neal and Jos. It was nice to get out for the night but the fly in the ointment was an unfolding family crisis back at home. That had to be left in the hands of other family members overnight as there was nothing we could do about it!

Sunday saw us run back up to Fambridge again under motor. No funny looks this time as the wind was, in any case, due wrong blowing straight down the river. Given the overnight wind forecast and the need to unload the boat and get away as early as possible the next day, we decided to splash the cash and go alongside for the night.

We really do need to cut down on the amount of kit we take away with us as it takes way too much time and effort to cart it to and from the van to the boat! Anyway, by mid-morning we were ready for the off.

There was a stiff breeze blowing downriver and a bit of a chop running but we succeeded in picking up our mooring at the first attempt. Getting the second buoy tail aboard and made fast was a bit of an excercise though as it had wrapped itself around the riser chain. A bit of faffing about and we got it sorted and made fast.

All that remained was to shut down and switch off everything - seacocks closed, gas and electric off and isolated, all things that lock locked and that was that. A ride ashore on the trot boat and away home.

So ended a very pleasing eleven days. Pagan is back in commission and shapng up. I am feeling the love again, it's been sheer bloody mindedness that's got us through the last 12 months as a year ago we were on the ragged edge of calling it a day.

There's still a mahoosive to-do list but it's back to being things we planned and/or anticipated.

We're not sure exactly what our plans are for the rest of the summer and autumn as a combination of Jane's work rota being changed, yet again, and the aformentioned domestic crisis (a very elderly father who up until now has been able to care for himself but may now need someone present 24/7), mean that we're going to have to re-plan and change holiday bookings etc.

I'm hoping we can get out for a short cruise to somewhere other than the River Crouch before the season is over. We'll see.

We're also undecided about whether to haul out for the winter or leave her in. Hauling out is expensive but on the other hand it's not easy to do significant work on the boat when she's in the water. And by next spring there are several projects I want finished - the v-berth refit, fitting new anchoring gear including an electric winch and new domestic batteries and charger/inverter being the main ones.

Onwards and upwards ...