Shunting Puzzle to become a BLT

Hi Kevin,

That information (legless) would have saved half a reply. If the baseboard heights are identical it sounds like an alignment issue. If you remove the cabinet makers dowels what is the difference in height? Is the alignment 1/32" out or are the boards 1 /32" out? If the latter then code 100 track if lower, sand a "cutting" if higher. If the former redo the holes. You should probably have catches on each side of the frames to keep them in alignment and in place.

Nigel
Edit: Might be worthwhile using adjusters at the corners of the modules anyway, especially if you go travelling, floors and tables thereon tend to be anything but level.

Hi Nigel  Half an answer coming up. The boards were level at the surface,. I am going to remove one dowel and drill a bit deeper trying to square the hole?  I haven’t fitted the catches yet.  Best wishes Kevin 

I'd be inclined to remove both male and female dowels and re-drill Kevin.  There doesn't seem much point to me in having alignment dowels that don't align ……………………. :???:
If you clamp both end faces together tightly and drill through both at the same time with a small drill to mark the centre of the dowel positions.

Having said that, 1/32 isn't a huge difference so maybe you could just shim up the tracks on the lower board.  :roll:

Hi Petermac.  Thank you. That is the way I used to fit them, but by fitting the female dowel first, and then placing the male into the female, as I did, then when you offer up the second board , it punche two centre “dots” ready for drilling..I know that I may live to regret my “ faux pas”, but I will leave it for now, and maybe , one day I will make a “third board “? Giving me a twelve foot end to end, and swap it around to fit.  Best wishes. Kevin

Hi Kevin,

I gave up on these some years ago, along with side clasps, Pair of plastic C-clamps holding the ends together works fine. One thing I did note when I used them was that it is essential that the drill is at exactly 90° (horizontally and vertically) when drilling the hole for the female half. Using a dowel jig helps. Get that even slightly out by a couple of degrees and it will never fit properly.

These alignment pins used to come in 2 varieties - exact fit (tight), and sloppy fit (the sleeve is drilled slightly oversize). The latter is the one to use as it allows for expansion and contraction of the wood. The male pin should be steel, the sleeve brass.

Nigel

Hi Nigel thank you. The C & L. type fitted into the recommended 25mm recess are a tight fit, when you say “plastic C clamps” I do have some “G Clamps” but they are made of iron, also I have lightweight “quick grips “ which are a combo of plastic and metal. As for a jig? I don’t have one. Best wishes. Kevin

Hi Kevin,

Tight fit = 100% accuracy in drilling the holes. IMO a bad design that does not allow for expansion/contraction. They are meant for furniture that gets dismantled infrequently.

The only issue with clamps is that they need a bit of space underneath. Works well with legs or levelers.

Nigel

Hi Nigel.   The clamps are only a temporary measure to hold the job in position until one drills the holes.Best wishes. Kevin

Hi Kevin,
I use them to hold modules in alignment. Permanent set of modules gets 2 big NBWs between each one. Clamps are the tried and trusted method of most if not all modular groups.

Nigel

Hi Nigel       The difference with my set up is the original idea for the Shunting Puzzle is for stowage and travel. Built like a toolbox, but with two lids.   Which means that the underside is inaccessible  and clamping is impossible . My original idea , before I even heard of “Modules” was in fact just that, four baseboards each with a pair of  C & L dowels and three “quick grips” to hold them together to form an L shape. But it has only been used as a Bench.  Best wishes. Kevin

Nigel, Petermac ,  Update. I have just revisited the baseboard , I removed the C & L dowels, and offered up the fiddleyard board. It was the boards that were uneven, not the dowels, and by the same amount , I don’t know how because it was cut on the Sawbench operated by the timber merchant .  Best wishes. Kevin

Hi Kevin,
Some pointers for the future, as ply has to be treated differently to finished soft or hard wood.:

Merchant saws. Unless well maintained and operated properly the precision is usually +/- 1/8" at best for a horizontal saw, and can be even worse for a vertical one, especially at the end of a sheet. The last 6" is usually discarded because of a lack of vertical support at the bottom. Unless it is a real mill shop the aim is to cut it up so it fits in the car. Ask when the blade was last replaced or sharpened. If they do not know walk out.

You should always insist that the sheet is squared before cutting the sides and the top. And always check the dimension after the first cut when squared. 

Always check the piece you want, if it is square then the diagonal measurements will be the same. There can be up to 1/4" - 1/2" difference in  a sheet. I always have it squared anyway. A good shop will ask if you want it squared. If they do not ask walk out. They do not know what they are doing.

Large pieces of ply are best cut vertically, even a large professional  table saw is problematic for a 5 x 5 feet piece. It needs two operators, one to push, one to guide and support. With a vertical saw a stop at the bottom controls the width, they may not be exactly 4" , but they will all be the same. Plus it will have a smaller blade compared to the table saw, less wobble.

Do not be tempted to have long cuts done with a radial arm saw. End cuts only as they have cross cut blades that will wobble in a long cut. Ply needs a sacrificial piece underneath to prevent splintering.

Some level adjusters at each corner of the boards would solve the problem.

All bin there dun that experiences.

Nigel

Hi Nigel . Thank  you, but, this is south London , in the 21st century, as of course you know. And workmanship as gone out of the window? “. Lackadaisically “ being the order of the day, speaking of which? I did notice that there are some very rough edges, and it would seem the more that I “sand them the rougher they become” . Would you please tell me how to get rid of them?  Best wishes. Kevin

I was also about to ask you Nigel - when you last had sheet material cut in the UK ………………..?

Sharp blades, properly set and unworn stops - dream on !!! 

You get what they give you although that is significantly better than the softwood market here in France.  A piece of PSE softwood machined to anything less than 75 x 75mm,  any longer than 10 cms is likely to be bent like a banana.

I've hunted through their stocks and walked out, unable to find a single usable piece.

 They claim the problem is that here in France, most wood is sun dried in big sectioned chunks and of course, unseasoned.  Result - a moisture content of around 15%.

When they cut it down to smaller sections, all the stresses are released, sometimes over a couple of weeks.  Buying in "tied" bundles is definely a no-no.  The ties hold it all together - cut those and boing……….. it goes everywhere…………………
 

[user=1801]Passed Driver[/user] wrote:

Hi Nigel . Thank  you, but, this is south London , in the 21st century, as of course you know. And workmanship as gone out of the window? “. Lackadaisically “ being the order of the day, speaking of which? I did notice that there are some very rough edges, and it would seem the more that I “sand them the rougher they become” . Would you please tell me how to get rid of them?  Best wishes. Kevin

Hi Kevin,
Get better quality ply such as Baltic birch. Keep away from cheap 3-ply core with  a 1/16" veneer on both sides. Low grade lumber has coarse fibers that splinter rather than being chipped, especially if it has a high moisture content.

Speciality wood shops that cater to diy furniture makers or to cabinet makers stock it. Whitten Timber in Peckham have it. Look and you will find.

Be warned - must lumber these days is Chinese with a high moisture content. Make sure the Baltic birch comes from either Latvia or Russia. Both adhere to ST standards.

Nigel

Hi Nigel.  Thank you.  But, Whitten Timber is my local supplier . If I was a car/van driver? I would not have a problem, there is another supplier “ Wickes “, and I could get there by train. I looked up Baltic Birch on the net, but how do I know the origins???  Best wishes. Kevin

Hi Kevin,
Origin? Ask. It is usually Finish, Latvian or Russian. You should also make sure one side is bb. Cabinet interior grade. It will have a few rugby ball patches where knots were removed.

Good quality has no voids or overlaps, is not warped, and the external plies will be the same thickness as the interior ones. Comes metric, so 12 is the nearest to half an inch, 6 to a quarter. Usual cut size is 5 x5 feet.

Nigel

Hi Nigel   Thank you.  With so many baseboards already. Seven in total including the four originals, two Shunting Puzzles, and one BLT extension . I will put this info into the “ memory bank “ for the present, unless that is , I rebuild the originals.  Best wishes. Kevin

Hi Kevin,
Baseboard modules are what we put everything on and under. It makes sense to do it right. I've used Baltic birch ply for every module I've built (quite a few) except the first two (frame, bracing, top). And recently no screws for the frame, just the top. If and when I have to use softwood it's Radiata pine from NZ, nice and light and minimal warping.

The above works for me, others have their preferred approach. In the long run I think it pays to use the best materials you can afford, otherwise it can often be false economy.

Nigel

Hi Nigel.   As you know I have “ been out of the game for about fifty years , incidently? At just about the time I sold my model railways stuff,  was the time when “ Shunting Puzzles were all the rage”. And baseboard frames AFAIK  were built on 2” x 1” soft timber , a better quality than is available today. If I can “stop the train for a moment”? On another subject , “three way points” how do I wire them for “WIT “? Is it the same as wiring two separate sets of points???     Sorry for that.  Best wishes. Kevin