Monthly Archives: January 2016

Laser Bench

The Sheffield Hackspace needed a better set up to make there laser cutter more accessible and easier to work around. Currently there was a small temporary bench with an old desk worktop on it. It was not the most stable work surface in the world and there was very little work surface for assembling parts etc and the current bench didn’t  provide much storage space because of the height of it’s shelf. The high of the worktop also needed to be increased as some people strained to lean over and operate the laser cutter.

With these points in mind I began to sketch out some ideas on paper. The current bench was sat in front of the window at the far end of the workshop and was 1350mm long, the new bench would span the width of the workshop at 2400mm. There also needs to be room to incorporate the laser chiller this was 280mm wide the easiest way to make a place to put it was to shorten the whole frame down to 2100mm and let the worktop over hang the gap, as for the height it was brought up to 925mm, at this height the work top would sit level with the windowsill. The bench frame will be supported with 6 posts and joined using through morits and tenon joints, There will be a shelf running through the centre for storage of large sheet goods. I drew up a 3D CAD model using FreeCAD to plan out the design.

Completed 3D CAD model

Completed 3D CAD model

With the 3D model made and all of the timber cut down to length the mortises where marked out. To ensure that all of the measurements where consistent I marked all the heights of the mortises on an off cut of ply the same height as the posts. This was then held flush with the base of the post whiles the marks where transferred over and extended with a square, with that done the width of the mortise was marked on using a mortise marking gauge.

Using a 15mm forstner bit set to a depth of 45mm in the drill press I removed the bulk of the waste material. Followed the rest of the waste material being removed with a chisel using the same technique u24395718091_855c8ce72c_osed in previous projects, this was process was repeated for all 24 mortises. I then rounded over the edges of the posts using a 1/2″ round over bit.

The ends of the through tenons where cut using the band saw, I set up the fens and a stop block to cut the ends accurately. With all the ends of the through tenons cut I began to assemble the middle, left and right hand side sections. Glue was applied in the mortises and the through tenons where inserted it to the mortises. The assembly was held together with a pair of sach camps whilst I drilled a countersunk pilot hole and drove a screw.
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With the 3 cross sections completed I began to assemble the frame together by laying down one end section and applying more glue in the mortises then setting the 4 cross shelf supports in place and driving a screw in from behind. I then added the middle section and repeated the same process for the top half of the bench.

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I then turned the workbench around the right way up and butted it up against the wall on the right. I cut two shelf’s out of OSB and fitted them around the square posts then dropped them in place. The worktop was then cut to length and width, for transportation purposes it was cut into two separate pieces. It was then secured with a screw countersunk in to each corner of each half of the worktop.

Completed Laser Bench

Completed Laser Bench

Overall this has been a great project and makes much better use of the back end of the workshop, there is more room for assembling prototype models to the right and an additional shelf for storing consumables. The bench is strong and sturdy and it will take many years of use to come.

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For more build image visit my Flicker page.

Wet Bench – Kitchen area for Sheffield Hacksapce

I had been tasked with the job of building a replacement kitchen unit to replace an old one that had been ripped out during refurbishment works at Sheffield Hackspace The space needed somewhere that people could make food and drinks but also served as an area for PCB etching and other activities using hazardous chemicals without the risk of cross contamination.

I was given a specification of what the ‘Wet Bench’ must have to make it practically useful and safe in the environment it would be set in, the list follows:

  • The height of the worksurface must be at the same level as the window ledge
  • Span the width from the door to the start of the 3rd window inwards
  • House two sinks, one at either end
  • Utilise storage space below with at least one shelf
  • Provide a space under each of the sinks to accommodate a water heater at one end and a space for a bucket under the other.

The bench will span 2600mm wide and stand off the wall 600mm. There will be a sink situated at either end, the one of the right will be for food and drinks it will have a water heater sat below, the sink on the left will be for handling hazardous substances when doing activeness such as PCB etching, when these types of activities do occur the trap of the sink can be removed and a bucket can be placed below. There will be a shelf in the middle of  the frame that will be used as storage.

With all of this in mind I needed to choose some material to use. I decided to go with some PSE (Plain Square Edge) timber. I used 69×69 for the posts and 20×69 for the through tenons.

The frame will be constructed using a series of mortis and through tenon joints. The reason I have opted for this method is because they are a strong and reliable joint because it gives you a large surface area to apply glue to.

Now that I had all of these details I could begin to make a model to work to, I used FreeCAD to design the frame. You can see that the two rectangular areas that are directly below the sink openings leave space for a water heater on the right and a bucket or tank on the left. The OSB shelf on very bottom is split in four sections, this is so that the boards under neigh the sink can be replaced in the case of any water damage. The central shelf allows for additional storage, all of the posts have had there edges rounded over to give them a more aesthetic look and smoother to touch.

Compleat Wet Bench

 

 

 

 

 

 

 

through tennons 2

through tennons 1

 

 

 

 

To begin work I started by cutting all of the material down to the required length using a mitre saw. For cutting a series of components witch were all the same I stacked the material on top of each other and ensured that the end was square, this way I could get up to 4 of the same lengths at once saving time in the build.

After this process had been completed I moved on to marking out for the mortises on the posts. Whilst doing this I realise that it would be much easier to use some form of a jig to do the marking, so I decided to make one. As shown in the image below there is a base set at 90 and four supports on either side to keep the post square and the mortises marked out at the corresponding heights. All I had to do now was to place the posts in the jig and draw the top and bottom line then join them together using a mortis marking gauge.

Mortis marking jig

Mortis marking jig

With all of the mortises marked out I used a plunge router with an 18mm 2-flut cutting bit. I set up the fense on the router so that the cutter was positioned in the centre of the post, the depth stop was then set to 45mm (2/3 the way in). I clamped two pices of scrap timber on either side of the post to prevent me from inadvertently overshooting  the mortise. When routing the mortise I went down in 3 passes when removing material.

Routing the mortises

Routing the mortises

Posts with the edges rounded

Posts with the edges rounded

 

 

 

 

 

 

Now this task had been completed I rounded over the edges of the posts using a 1/4″ round over bit. I ran the cutter over a scrap piece of timber first to ensure that the router was set correctly and make any adjustments if needed. With all of the mortises routed they where squared off using a chisel.

For cutting the through tenons I marked them up using a combination square. Each tenon has either 1/2 or 1/3 x 20mm removed from the edge, the 1/3 tenons are for the central sections where ‘T”s are formed. These joints where machined using a band saw, I set up the fens and an end stop so that I could run through all of the necessary parts before resetting the machine to of the other 1/3 through tenors.

I now begin to assemble the frame, I started by assembling the two rectangular shaped units that would sit on either end, these two individual units would be joined together by the cross shelf supports making it one unit. The joints where fixed together using an expanding glue which fills gaps. Once glue had been applied to the joint and the through tenon had been inserted it was secured in place using a few wood screws, this pulls the joint tight and prevents it from setting uneven or out of square.

One side of the frame assembled

One side of the frame assembled

Once the two end sections had been created I set out to join them both together. I laid one of the side units on its side and glued in all of the 6 through tenons and secured them in place.

The assembled frame

The assembled frame

I then proceeded to measure and cut out some shelfs for the frame, I used 18mm OSB. The bottom section of the frames shelfs where cut individual in four sections, this was the same for the central shelf but this time it was split in to two parts, A number of screws where then added to keep the shelfs held down and secure.

The completed wet bench

The completed wet bench

The worktop was then cut size and mounted on top of the frame and secured in place. The two holes for the sinks where then cut out using a router and the taps where installed. All that was left now was to plumb in the sink and connect the taps up to the water main.

Overall this has been a great build and I have gained more skills from doing so. If I was to do this job again I’d improve the frame design and make it and construct it as a cabinet using sheet materials. This in turn would then allow me to hang doors on the exterior, witch would make the presentation of the work surface much more neater.

 

 

 

 

 

 

A new workbench for the Hackspace

After completion of the restoration in the workshop at the Sheffield Hardware Hackers and Makers Hackspace, we needed to sort out the most important item in any workshop, the workbench…
The decision was made to build our own, not only would this work out cheaper for us but I can make it exactly how people want it. However there was a list of criteria that the workbench needed to have in order to fur fill it’s purpose in the Hackspace. Together we came up with a list of what we wanted the bench to feature:

– Provide a work surface that is suitable for people of all heights to work at.
– Allow the front part of the bench to overhang the frame so that things such as vices and clamps can be secured in place.
– Integrate storage shelf’s for boxes and tools both above and below the work surface.
– Utilise as much space as possible to increase storage area at the back section of the workshop.
– The work bench must be free standing as it is being constructed in a grade 2 listed building.

Method of joinery

Now I had a list of criteria to work to I could start to plan out what process I am going to use. My plan was to use through mortise and tenon joints. With this in mind I began to sketch out some ideas. Below on the left  you can see the area that the bench would be constructed in. The workbench would be an ‘L’ shape, it would be 1900mm wide spanning the width of the rear wall, 1200mm from the back of the wall down the left hand side of the wall, the frame will be 600mm wide, the worktop height will be 1025 and the overall height will be 2000mm. You can also see the sketch that I made of the location where the support posts would be positioned.

Layout of the support posts

Layout of the support posts

The area where the workbench will be built

The area where the workbench will be built

By now I had a good understanding of what I needed to accomplish. In order to plan out how I was going to construct each individual component I started to draw out a 3D model of the workbench in FreeCAD.

Each of the individual components that made up the frame had to be designed individually. The construction consists of 8 vertical posts that support the through tenons witch are fixed in to. The 5 posts that surround the perimeter of the two walls are 2M tall, these will support the back half of the shelf’s that will rest above the work surface. The other 3 the posts surrounding the front perimeter will support the work surface from the bottom side of the work top and the shelf’s below.

 

 

CAD Work

Once all of the individual parts have been produced in FreeCAD they are exported as .step files so that they can be imported in to one model and assembled. The individual parts can then be moved around in different dimensions to make them all fit together. At the stage of assembling the parts it is clear if the design is going to fit together as intended, if say for instance a mortise has been placed to far down from the tenon to fit in to it at the correct level, this can be addresses by going back to the individual part and edit the mortise to the correct height.

Completed CAD model of the workbench

Completed CAD model of the workbench

Cutting the timber and marking out the joints

Now that I have a design in place I can begin to cut the material to length. The supporting posts are 70×70 and the through tennons are 20×70 redwood PSE. All of the  individual parts where cut to length. For the through tenon lengths that where all the same length I stacked 3 lengths of stock on top of each other and lined the ends up squer, not only did this save time but is also more accurate because they where all cut at the the same because one end of all of the material was square.

To mark out the positions of the mortises I used a tape measure, square and mortis marking gauge. I marked out the height of each mortis from the base and marked out a line on to the other relevant sides using a square. This process was repeated on all of the supporting posts. The image below shows part of a post that has been scribed out, 2/3 of the material will be removed from each side that has been marked, this section marked out is section where two through tenons will be seated to form a shelf.

A marked out post ready for machineing

A marked up post ready for machining

 

 

 

 

 

 

Machining the joints 

Once all of the joints had been marked out I set up for machining. To drill out the material I used a used a drill mounted vertically in a plywood jig witch was made by a friend. The jig was made in two parts, the first was the base witch held itself central to the post with two bits of ply fixd on either side of the base. The other part of the jig was joined to the base by a set of sliding rails, with makes it easy to manoeuvre. The last feature is the depth stop, this was incorporated by using a bolt and two nuts, it ensured that the spade bit did not travel more than 45mm in to the timber.

There are three different types of posts in the workbench, the first have two mortises that meet at 90° the second has three mortises that meet as a ‘T’ and the last has a mortise on every side that meet as an ‘+’. The 90 posts sit in the far corners, ‘T’ posts sit in-between the posts in the far corners and the ‘+’ post sits directly in the middle of the frame supporting the central weight.

Once the bulk of the material has been drilled out of the mortises they are ready to be squared off. I started by cutting around the perimeter of the mortise, I did this by setting my chisel on the line and tapping it gently with a mallet to set in in place to stop it from slipping, I could than continue with a stronger strike to remove more material. Once I had been around the exterior of the mortise three to four times I could begin to start and lift material out. With the bulck of the waste removed I used a wider 25mm chisel to pair back additional material from the sides until the tenon fitted snugly.

Dry fitting

Now all the posts and through tennons have been mortised and squared off The individual sections that make up the workbench where offer up to each other before glueing. Offering up all the separate sections as shown below ensures everything will fit together as intended once it has been glued up this gives me the opportunity to pair off any excess material in the mortises using a chisel.

Offering up the components to each other

Offering up the components to each other

 

 

 

 

 

 

The assembly process

The workbench was assembled in three main sections, the back, the left hand side and the middle. I used an expanding glue witch was moisture activated, because this glue expands it fills gaps at the same time. The image below shows the back and left hand side being glued up. Once all of the back rails has been slid in to place along the back and side glue was applied in to the mortises, the tenon was then inserted in to the groove and a screw was driven in to hold the components in whilst the glue set.

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Assembling the section of the workbench

 

 

 

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The assembled frame

Installing the shelfs and worktop

Once the frame had been completed  the shelfs and worktop where installed. The shelves are 18mm OSB cut to size, the worktop is a piece of 25mm thick teak. To install the shelfs a measurement was taken of the length and width of the opening. Once this had been cut to size it needed to be shaped around the posts. The square cut outs for the posts where marked on and cut out. The shelf could then be fitted in place.

The worktop was mounted in two sections, the first was the pice that runs the length of the left hand side, towards the front side of the workbench a notch was cut out at 45 to allow the other pice to be seated on the rail with a corresponding notch in the other section of the worktop. With the worktop set in place the shelf support posts for the upper shelf’s where glued and inserted in to the cross tenons followed by a piece of OSB for the shelf.

almost completed workbench with upper shelf's assembled

almost completed workbench with upper shelf’s assembled

Overall this has been a great build and has produced some excellent results. The workbench fulfils it’s intended purpose, because of the method of joinery used it is a solid structure that will and will take many years of use. The worktop is at a suitable working height, an improvement witch I feel could be made is to install a backstop to prevent things from falling behind the worktop and add at least 4 double plug sockets along the back secured in angled back boxes, this in turn provides better power access for power tools and battery charges etc. The lower shelf’s make plenty of storage space for pats and components, as for the upper smaller shelf’s make an ideal place to put component trays and store power tools, it gives quicker access to the kit that will be used most often. I have enjoyed doing this build and have learnt some new skills along the way, I’m looking forward to future projects identical to this.

Compleated workbench

Compleated workbench

For more build images visit my Flicker page