Friday, 22 March 2013

Magnet housings

Not the best picture but what this is is the front door flap when its folded out. I will be going over the life scale drawings with fine liner after wards when the project is done to make things clearer. What I needed to do was to create a tracing transfer of it since I needed to transfer the image to the plywood door panels to mark out where the magnet housings needed to go.

Was also needing to refer back to the computer drawings since most of the developed information on the cabinet was on the computer through sketch up. When everything is sorted out 100 percent than the computer information will be transfered to the life scale drawings. I have not bothered to completely add everything and fix up some of the life scale drawings yet since things may change at the end of the project to certain things not working and needing to come up with a better alternative.

Image transfer done except for the magnet housing locations. I didn't put the housings in yet since I still did not know what size I had to make also how many housings to place. There needed to be some research and testing done.

I weighed the door and it weighed 2.5kgs. Now this door still had to have the 20mm offset around it to be taken off. But I guess this weight wouldn't change that much since the veneer and edging would still need to be added along with the magnets and other components.  So it would be give or take by a little bit to the end weight of a single door.

I found that the industrial supplies place that I go to thats just around from my work sold magnet supplies.
Most of the magnets I couldn't use either they were too heavy and too large or the magnetic filed was to high. The magnets had to be less than 16mm in thickness due to this being the thickness of the door.

I wanted to try and find a strong enough magnet that was going to hold up the doors with out any help (especially the folded front door flaps). But not strong enough where it was going to be annoying to unfold them/ close them.

I was looking for cicular magnets. This meant that I could easily cut out a hollow circle section with the Fostner drill bits or spade drill bits.  More so the Fostner drill bits since the point of the drill bit is not as long as the spade drill, didnt want the long point blowing through to the other side of the door. the link to this company. If your wanting magnets try this other company first since I have been told they are good. (insert name)

I had to do some magnet testing to see how many magnets I was going to need what locations they were going to need to be put in but most importantly whether this were going to be the right magnets to use. At first I was just doing a few tests to see how strong the magnetic field was for the magnets.

I just bought 4 magnets at first they were 15mm in diameter and 7mm in thickness. They were 4 dollars each so in total was 16 dollars.

The plywood covering was going to be the 3mm plug thickness that I was going to use to cover up the magnets when placed into the door. As for the paddle pop sticks they were referencing to the 2.5mm gap caused from the ZYSA hinges between the two door flap sections of the front doors.

For one magnet the magnetic field was pretty strong but I don't reckon just one would hold up the folded door flap section by its self. So I decided to try 2 magnets. Now this isn't a total accurate measuring of how much the magnets can hold this is merely just to see the magnetic field and how strong it was.

To obtain a proper reading of how much weight the magnets could hold and how easy it would be to un fold the door flap sections would be making a fake door that is the same size and roughly the same weight ratio as the final door.

I held up the test piece and the magnetic field of just one magnet was able to easily hold up the bottom section.

I decided to do another test piece that had 2 magnets in it. Now I ran into a little problem here. I could not have the magnets this close since the magnetic field between them was too strong and they wanted to connect to one another. This wouldn't be so much of an issue if each one was glued down individually. But over time with the glue weakening I didn't want to take any chances of it having the possibility of damaging the veneer.  These magnets are quite strong for their size.

I worked out with a few testing as to what the distance was going to be before the magnets started to be drawn to one another and where they would stay stable since they would be out of one another's magnetic field.

From the middle point the black crosses were 60mm apart. As for the red crosses they were 80mm apart. Each gap between the lines represents 20mm, The red crosses were where the magnets were not moving towards one another.

Drilled new holes in scrap and began testing again. I was using a 17mm spade drill since that was all I had. But I realized that I was going to need to make a larger hole in diameter compared to the diameter of the magnet. There needed to be enough room for the glue to sit around the magnet. I planned on using araldite, but will need to so some tests first to see whether the bonding would work properly.

Covered up sections and began testing again.

The magnetic field increased heaps and was able to lift a lot more weight. It still was easy to take apart with out any strain.

Another test I will be doing is to see how much weight the bottom section can take before the two break apart. Will be doing this along with making the fake door before any magnets are glued into the doors. If I find that I dont need some of the holes will just plug up with larger dowel plugs.

Began transferring life scale drawings of cross over lapping of the front door flap and the back door to tracing paper which will than add in the magnet sections than transfer to the plywood door substrate.

First had to work out the placement of the magnets in the folded section of the front door flap. What this section is is the over lapping section of the two flaps of the front door flap. This was don on sketch up.

Each magnet section was more than 80mm apart. I wanted to spread the magnets out enough where they would cover all support sections of the door flap. I didn't want the magnets too close to the ZYSA hinge sections on the fold line of the door. This was for a few reasons didn't want them to connect with the brass hinges that much in the magnetic field. Now the brass wouldn't actually connect with the magnets due to no iron particles. But there are a few screws that are in these hinges that are not brass and most likely steel. You will find also that aluminum will not connect to magnets as well due to not having any iron particles in it. Some times stainless steel has problems as well.

Also if the magnet connection was too close to the fold line and was too strong it would close the gapping up which I didn't want it to close up too much or expand to much, that is also why I didn't want the magnets to be to close to the back as well.

So I ended up having the magnets 30mm away from the edges. 30mm is from the edge of the magnet to the edge of the panel. Once drawn out on computer I could than transfer the information to the life scale traching paper image.

On the drawn out tracing paper section this is where the magnets would be placed. 

used circle guide to make the drawn in magnet sections.

Now that I worked out where the magnets were going to be place on the fold over lapped section I could than work out where they were going to be placed across the whole front door flap when in its upright position.

Even though the brass hinges had some steel in it to cause a magnetic connection they didn't draw to the magnets when being this close. This was going to be how close they were coming to be in real life when installed into the door.

Transferring the magnet housings to the plywood birch substrate panels for the doors. It doesn't matter if the magnets don't totally line up 100 percent since the magnetic field is pretty strong.

Both front door flaps now have the magnet housing locators transfered to them awaiting boring from fostner bit on drill press. I will be doing this at tafe.

Transferring the magnet housings to the back doors. The magnets in the back doors are to help hold up the front door flap when it is vertical. Not all the magnets that were from the front door flap corresponded to effective spots on the back doors. Some aligned up in the negative spaced sections others lined up to the back door edging. Only four magnets lined up in usable positions on the back doors from the front door flaps. Four magnets should be enough.

Back doors now have magnet housings drawn on to them awaiting to be bored on the drill press. 

Since the magnets were 7mm in thickness and the dowel plugs were going to be 5mm. I needed to make the magnet housings 10mm deep. 2mm of the dowel plug would sit out above from the door and would be cleaned up with a hand planer or a flexible saw than a cabinet scraper after being glued in. Need to make the dowel plugs totally flush with the doors so when veneered there is not a raised section or a sunken section due to the plug being to low. Any gaps surrounding the plug to the magnet housing hole would be bogged up with builders bog before veneering.

Needed to drill into a scrap piece of plywood first that was going to be the same thickness as the doors. This is so I could make sure that I was going to get the right depth. I ended up using a 16mm fostner drill bit the next size up was 19mm which was going to be too big and would leave to much slack in the housing for the magnet.

Using the calipers made sure that I was going to obtain the correct depth for the housing.

Decided to use a waste board to obtain more support for th doors to sit on while boring the magnet housings but also to prevent damage to the doors from the rough metal drill press plate.

Magnet sits in the test housing at the correct depth still allowing 3mm of dowel plug to sit in before becoming level to the top surface face of the door.

First magnet housing made in doors. With the fostner bit need to be careful of the pointed section making sure it would not blow through the other side. The pointed section on spade drills is a lot longer due to removing bulk amounts of waste.

Magnet housings made in the back doors on the drill press.

Magnet housings made in the front door flaps.

Rough alignment as to how doors will look like.

Making sure that magnet housings line up with drawn out transfer paper of life scale drawing.

Originally I was going to use a different jig. The jig I was going to make was going to have a base where two build sides would sit on it would be miter on the inside which would create a V grove. In this V grove I would use the friction grip matting that I have used for previous jigs. I saw this idea for a drill press drilling jig for cylinder shapes in a guys work shop. My tafe teacher gave me this idea. Said it would be a lot safer and would prevent chip out. Would be a perfect jig for cutting very small plugs.

I had to make a jig which it was going to cut the 5mm dowel plugs safely and cleanly with out any break out and square and straight. At first I was going to use the same Fostner drill bit. Talked with my tafe teacher and he suggested that it would be best to use a spade drill since it would be able to go deeper and be able to remove bulks of waste more comfortably not putting strain on the timber and the drill bit its self. The above Fostner drill bits are not designed to go to deep lengths.

I had to make a 100mm deep bored hole so a lot of waste needed to be removed.

The bored 16mm hole needed to be offset closer to the bottom and front cutting edge. There was going to be two pieces. The first piece would be glued down to a base and the other would be used more for support at the end of the dowel. This one would not be glued down as it would be moving along the dowel rod the shorter it got while cutting the pieces.

I was going to use MDF as a base but the timber didn't bond to well to it with glue so I decided to scrap it and use a scrap piece of timber.

The bored holes were a bit snug so I had to clean them out with some cylinder files and come course sand paper about a 80 grit.

Clamped down to a base and did a test to see how well the dowel rod moved through the slotting.

Scrapped the idea of using a MDF base and made a new timber base from some Fijian Cedar in the tafe work shop. Had to dress it first on the jointer than through the thicknesser.

Glued down the front dowel holder piece. When applying the glue just gave it a rub with the base that it was bonding to than left for about 15 minutes long enough for the glue to cure in which the clamps would not make the piece slip when clamping up. I didn't need that much clamp pressure so I used some quick grip clamps.

Before making the final adjustments to the jig after leaving it to dry for about 2 hours had to dress the front edge since this edge had to be square and flush since it would be sitting up against the panel saw docking fence.

I had to raise the panel saw blade to 45mm as this is where the top section of the dowel hole ended from the bottom of the base. I wanted to make 5mm dowel plug pieces so what I needed to do was set the sliding rip fence just behind the blade and set it to a cutting depth of 5mm. This cut was going to act as a the saw trench to cut the dowel inside the wooden block section. Once the cut would be made just push the dowel rod further down pushing out the little piece cut. For the next cut the dowel rod needed to be flush with the end of the block. The end of the block is what is resting up against the ripping fence on the panel saw.

Have to be careful not to break this section off since it is only staying on there from a little bit of un cut material. While half way through the job of cutting the plugs I already broke it once and had to re set up every thing to continue the job.

The size of the plugs that were cut.

Jig being used to cut the plugs on the panel saw.

Plugs used to cover up the magnets they sit out by 2mm.

I wont be gluing them in straight way as I need to still do some testing to see whether there are two many magnets and the force is too strong or whether ill need more magnet housings.

Adding in the placements of the new magnet housings that need to be made into the front door flaps and back door before veneering takes place.

These new magnet housings will be drilled at tafe on the pedestal drill. I will need to buy some more magnets and also make more magnet housings dowel plugs.

Also transfered the new magnet housings to the transfer paper for future reference if needed.

I had to cut some more dowel plugs on the panel saw using the dowel plug jig that I made. These dowel plugs were going to be for the new magnet housings that I needed to make.

Boring the new magnet housings in the back and front door flaps on the pedestal drill at tafe.

Making sure that all the magnet housings matched up to the magnet housings on the transfer paper. The transfer paper had the over lapping of the front door flap in accordance to the back doors magnet housings.

The magnets don't have to totally line up with one another 100 percent. The magnetic field for the magnets is really strong so it wont mater if the magnets are not in  total alignment. Some of the magnets are out by a couple of mm to the transfer paper locations of the magnets.

Magnet housings made for the doors and now are ready to have magnets glued into them with araldite.

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