Friday, 22 November 2013

Revolving disc/belt sander table ...

I've recently gained a new toy, it was a birthday present and something I've thought about getting for a while, it's a disc and belt sander, great little tools.

The problem I have is limited space in my shed come workshop and for a while now I've been trying to get it into a more orderly and usable fashion, but with space at a premium I've had to think a little differently.

The sander isn't a big item, but even so it's large enough to cause the small issue of where to put it, so I had to come up with a solution that means I can use the sander easily in the space it now lives.

Here's the sander -

Great little bit of kit.

As you can see it's already attached to the platform I built for it, you can also see that it has a belt sander at the front and a disc sander at the side, and here in lies the problem, in order to use it I'd have to keep picking the whole thing up and turning it round, which isn't I agree that much of a problem, but as I want it to stay in one place when I use it I intended to fix it to my work bench, and having to remove screws each time I want to use the sander was more hassle than I wanted, so I built a turn table for it, which it's already fixed to in the picture.

The turn table consists of two squares of wood, which I cut a little larger than the base of the sander, on one piece of wood I've fixed small wheels and with a bolt through the middle the whole thing is able to turn 360 degrees, which means I just have to rotate the table when I want to use the disc, rather than the whole sander.

To build it I took my two bits of wood (some old cupboard doors) and drawing lines diagonally I found the centre of each bit, then drilled through both parts so that I could push a bolt through, and using the hole I drilled as a guide I drew a circle on the underside of one of the bits of wood, this is where the wheels go.

Wood with circle already drawn on, and bolt hole drilled - 

Not the neatest of jobs.

The wheels are small ones I found in a hardware shop, not very expensive, but perfect for what I wanted them for.

The wheels fixed in place - 

I'll get to the peg in the top right corner in a minute.

I used some small screws and roughly lined up the wheels so that they were more or less evenly spaced around the circle.

Close up of one of the wheels - 

Nothing special, just small plastic wheels.

I fixed two bits of wood to the underside of the bottom plate to allow for the bolt that goes all the way through.

Wood to create clearance for the bolt - 

I just used off cuts for this.

To reduce the amount of movement between the two wooden plates I used a short piece of tube to put the bolt through, this also means the whole thing revolves much more smoothly.

Small piece of copper tube to act as a sheath for the bolt - 

Small bits of tube always come in handy for something.

The bolt I used was just the first one I happened to find that was long enough, I tend to keep odd nuts and bolts for just this sort of thing, it's a bit rusty, but it does the job.

The bolt - 


Now with that done what I needed was a way to lock the turn table in place, not really usable if it's spinning about all over the place, so I made a simple spring loaded peg that locks into one of two holes depending on what part of the sander I want to use.

The peg consists of two bits of dowel, 12mm for each end and 9mm for the shaft that the spring sits on, I also used two washers to stop the spring going through the hole that the locking peg sits in.

The locking peg (underside so you can see the spring etc) - 

Simple but effective.

It's a simple solution, but it does mean I can lock the table in place, I was originally going to use two pegs, but for now I'll see how I go with one.

Here's the locking peg from another view - 

You should be able to see how it works.

Basically one end of the peg fits into a hole I drilled on the bottom plate, if I want to move the sander round I just pull the peg up and spin the top plate round, and then the peg as it's spring loaded automatically locks into place, the spring sits between the two larger bits of dowel, which I drilled holes in and then glued onto the smaller dowel.

Here's a few more pictures of the finished turn table - 

Sanding belt at front.

Table spins clockwise.

Now disc sander is at the front.

And here it is in my humble workshop, you can see that space is at a bit of a premium, but I think it will work out well, I can easily turn the sander round, and I've used a couple of small brackets to hold the turn table down, so it doesn't move about.

The sander in it's new home - 

Not much space.

Should be enough clearance around the sander.

All in all I'm quite pleased with the turn table, it should make it much easier to use the sander in it's little spot, and I think I've left enough room around it so it doesn't get in the way of my post drill, which you can't see in the pictures, but it's just to the right of the sander.

Thanks for reading.

Thursday, 14 November 2013

How to make toy crossbows ...

We've recently been looking at medieval weaponry, and siege warfare, and as a result of that we ended up making a trebuchet and an onager, both of which were used a lot for laying siege to castles and such like many years ago, weapons like these were the most advanced war machines around, on a recent trip to one of museums we were looking at armour, swords and other hand held weapons.

I decided it would be good for the kids to have a crossbow each (non lethal crossbow) this would show them how hand held weapons have changed over the years, and give them an idea of what soldiers would have had in the way of weaponry and what it might be like to use such a weapon.

Here's what we ended up with -

Not historically correct, but fun to play with.

As you can see they are very much toys, but they do show what it might have been like to load,aim and fire a weapon like a crossbow, I've included a video of my daughter using her crossbow in the garden, and I've also worked out how much it cost to make both crossbows, the cost for both of them comes in at a cheap £4.27 (that's for both crossbows) not bad, it will work out cheaper if you already have some spare bits of wood lying about.

Here's everything you'll need to make your own crossbow - 

Doesn't much look like it'll make a crossbow, but it does.

Ingredients list (for 1 bow) - 

  • 2 bits of batten, one at about 40cm and one at about 35cm in length.
  • 1 length of 9mm dowel & 1 length of 6mm dowel.
  • 2 old corks
  • 1 meter of elastic
  • 1 screw (about an inch or inch and a half will do)
  • 1 scrap piece of wood for a trigger.
  • A wooden skewer.
  • A wooden tooth pick.

The basic design is a cross shape, I've used batten for both bows, which can be bought in a pack of 8 x 1.8 meter lengths for £8.42 (from B&Q) I've been using this batten for a while to make things like this, it's cheap and quite versatile, I only used 1 length to make both bows, so if you get a pack you'll have some left over, or you could just buy a single length, which comes in at about £1.56 or there about.

Okay, first thing I did was to get the trigger set up, to do this you'll need to make a slot in the longer piece of batten, first measure in around 8cm from one end of the longer piece of batten and make a line, then measure about 6cm from the first line and make another line, now find the centre of the piece of wood and mark a line between the 2 marks you've already made.

Like this - 

Ready for drilling.

If you've ever made a mortise and tenon joint you'll find this easy, but it's not that hard any way, the next thing to do is drill some holes along the centre line, this makes it easier to slot for the trigger.

Holes drilled - 

Just needs tidying up.

I used my needle rasps (small rasp files) to tidy everything up, and once that was done I used a bit of sand paper to smooth it all.

Trigger slot done - 

Not perfect, but it'll do.

Next you want to mark down the sides of the longer piece of batten, you need to cut a notch out of the wood, this is where the elastic will sit when the bow is loaded.

Lines marked down the side, and notch marked out - 

I used a coping saw to cut it out.

Notch cut out - 

Some adjustment might be needed.

The next thing I did was to make a groove all the way down the longer piece of batten, this acts as a guide for the bolt, and makes it easier for the kids to use, to make the groove I marked a line down the centre and using a small sanding drum in my multi tool I sanded the groove out.

Groove line marked - 

I wasn't too precise.

Here's the sanding drum - 

These come in handy for all sorts of jobs.

Groove done - 

How easy was that ?

If you don't have a multi tool you can always use files and sand paper, it'll just take longer.

Back to the trigger, I cut out a rough shape from my scrap bit of wood (an old bit of tongue and groove) using my coping saw, then I gave it a sand to smooth it off a bit.

Basic trigger shape - 

I drew the shape free hand.

Cut out - 

It's about 8cm in length.

Next I tried it for fit, you want the trigger to be all the way forward, but just below the notch you made, the idea here is that when you pull the trigger it moves up and pushes the elastic out of the notch.

Trigger pin marked - 

Once drilled the 6mm dowel will work as a pivot.

Hole drilled, you can see the trigger is below the notch when fully forward - 

Just drill all the way through, this way the holes will line up.

Trigger pin sorted, just needs tweaking - 

Trigger done, just needs tidying up.

The next thing I did was to make a notch in the end of the batten opposite to the trigger, this is where the shorter piece of batten will sit, to mark out the notch I just set one piece of batten on top of the other and marked it out with a pencil.

Marking the notch - 

I had already marked the notch out.

Once you've cut the notch out of one piece, slide the other into it and mark out another notch, make sure that there's an equal amount of wood on either side of the notch, once you've cut out both notches you can slide the 2 parts together to check the fit, but don't fix it together yet.

Checking the fit - 

Looks good to me.

Once I was happy with the fit I marked out where I was going to drill a pilot hole for the screw that will hold the crossbow together.

Fixing hole marked - 

Just needs drilling.

Pilot hole and counter sink done - 

I used a bit of glue as well as the screw.

Next it was a case of making things look a little nicer, which basically meant rounding ends of, and giving the trigger a nice shape, I also had to drill out the holes to hold the bolts when the bows isn't in use, and the holes that hold the pegs that control how tight the elastic is.

Trigger shape done - 

I just cut out a half circle.

To round the ends off I drew round a plastic pot, and I used a protractor to mark out the curve for the cross piece.

Rounding ends off -

Anything round will do.
Nice curve.

Making the bow curve - 

Ready to cut out.

To make the bow curve I measured in from each end of the cross piece, then using a protractor I marked out a curve, then I cut it out roughly and smoothed it out using my lathe sander.

I also marked and drilled the holes for the adjuster pegs and the bolt holders, I marked the adjuster peg holes out by measuring down from the line I used to mark out the curve, and then I measured across about 1.5cm.

Adjuster peg holes marked - 

Easy peasy.

Once it was all cut out and sanded the next thing to do was to put it together, and then sort out the peg that holds the trigger in place and the 2 adjuster pegs, this is just a case of cutting a bit of dowel (I used the 6mm dowel) to the right length and then drilling a small hole all the way through it on both sides, then using a bit of skewer pushed into the holes on either side to stop the peg coming out.

Trigger peg sorted - 

This method works well, and looks good.

There's something about using pegs in this way that kind of makes things look older, and generally more aesthetically pleasing.

To make the adjuster pegs it's basically the same method I used for the trigger, but instead of using bits of skewer I used bits of toothpick and only in one end of each peg because the elastic needs to go through the other end of each peg.

Pegs made - 

Pegs done.
Holes drilled.

Next I threaded the elastic through the pegs - 

Loop in one peg.
Knot in the other peg.

I also made a small groove for each adjuster peg to sit in, this will stop them twisting and the elastic unwinding, the basic idea is that by twisting the pegs the elastic twists and gets tighter, this means you can adjust the amount of power in the bow string, the elastic I got for 40p from our local market (20p per metre)

Adjusting the elastic - 

Simple but effective.

Lastly the bolts, these are just lengths of 9mm dowel (about 24cm in length) with a cork stuck on the end, we have plenty of corks about the house because of our wine making exploits, to make the bolts just drill a hole in the end of the cork, make it slightly smaller than the dowel, then put some glue in the hole you drilled in the cork and then stick the dowel in, and that's it, you could also add fletchings (flights) to the bolts for greater range.

The bolts - 

Doesn't get much easier really.

Here's the video of my daughter firing her crossbow - 

Thanks for reading.