Introduction: Adjustable Drawing/drafting Table
My latest project is super important for me. I have recently decided to go back into product design and wanted an area that I can work from that isn't a boring desk. I decided to design and fabricate my own drawing/drafting table using steel A frame legs and a big hefty piece of Oak.
The design had 3 important parts that were a must.
1. It had to look industrial
2. It had to have a big chunky flat work surface
3. It needed to be adjustable
The gas strut allows me to set the table angle at any angle between 7 and 40 degrees meaning while drawing I can easily change the angle of the table to suit my needs by either pulling up or pushing down on the table.
Supplies
I used the following materials:
For the frame
6M of 40x40x3mm mild steel box section
The steel was supplied by Rapidmetals.co.uk, it was delivered within 2 days of the order being placed, packaged really well and secure, the pieces were cut to the correct length and cut at perfect 90degree angles (which when working with any material at exact lengths, this is important). You can see from the image attached that they amount of different materials they have available is huge and although they are called rapidmetals.co.uk they also have engineering plastics. Although there is a large amount of information on their website they also have an online chat and a super fast email response times.
This is the first time using this company and it will not be the last! I work on multiple projects each year and I will be using rapidmetals.co.uk for all. Thank you rapidmetals for supporting this project.
The mechanism
The adjustment of the table top angle is achieved using two flange bearing units with 20mm ID
One 250mm gas strut to keep the table top at the correct angle (The weight of the table top stops the strut from fully extending.
Two 100mm 20mm wide steel round bar
The table top
The table top is a 980x625x40mm solid Oak kitchen worktop offcut that was found on Facebook marketplace. I decided to use this as its big, chunky, aesthetically what I'm looking for and importantly its flat.
Step 1: Fabricating the a Frame Legs
The first thing I did was use my CNC software to create the legs digitally which gives me the exact angle needed at the top and bottom of the steel to achieve the correct angle of the A frame. I printed the angle sections, checked they were 40mm wide (width of the steel), cut them out and glued them to the ends of the steel with Pritt Stick. Doing this give me the exact lines i needed to cut in the steel and by putting a template on both sides of the steel it means the cuts on both sides are even, especially when cutting with an angle grinder!
I did the same thing for both ends of the leg for all four legs. Once the angles were cut I cleaned and chamfered the edges to allow for a better connection when welding, clamped two legs to the table in the correct place and stick welded down the seam.
When welding I tack welded on one side first, flipped the legs over, checked the joint was ok and welded fully around all edges. Once the top was welded I added small square caps to the bottom of the legs and cleaned all the welds up with a flap disc on the angle grinder.
Step 2: Fabricating the Table Top Mounts
The table top mounts were a very similar process to the A frame legs however I was able to scribe a 45degree line on the steel using a set square as a guide rather than printing the angles.
The mounts are 250mm pieces of steel box section with two 45degree angles, welded together to form a V shape. I created a small 45degree jig using my CNC machine for a project a number of years ago which came in handy to clamp the steel too, ensuring it stayed at the 45degree angle.
I also welded a 100mm piece of 20mm round steel in the corner of the V to create the pivot point. This was done with careful measurements and using welding magnets to keep it in place. Although this is critical, to ensure the pivot points are in the same place on both mounts, the flanged bearings do have some play in them if they don't sit exactly the same
Once the pivot pieces were welded I added extended caps onto the ends of the V and drilled two screw holes to allow me to fix them to the table top.
This was then repeated as two of these mounts are needed.
Step 3: Mounting the Bearings and the Table Top
Mounting the bearings
As the two A frame legs were identical mounting the bearings was easy. By pushing the bearing into the V at the top of the A frame it give me the point to drill for the mounting bolts. I did this for both legs ensuring the were equal before drilling.
I drilled and tapped an M10 hole for both mounting points on the legs, threaded an M10 bolt in and welded around the bolt, I then cut the top of the bolt off, slide the bearing over and tightened the nuts on.
I repeated this for both bolts on both legs.
Mounting the table top
Mounting the table top mounts was super easy. I chose the best side and laid it upside down on the floor, measured from the top edge down at both ends and drew a line, I also measured from the outside edge and marked a line around 25mm in. This gave me a line drawn corner to work from for the mounts. I ensured they were the same distance from the edge at both mounting points, drilled pilot holes and screwed the mounts to the top. The screws did poke through the other side but quickly grinded them flat
Once the mounting points were attached I slid the bearings over the pivot points with the legs attached and lifted the whole table up in together. The table top swings but I found it the easiest way to lift it as at the point it was very heavy.
Step 4: Adding the Brace and the Gas Strut
Mounting the brace
Once the table was standing I clamped the table top out of the way and measured down the legs and added a clamp onto the a leg on each end. I did this so the brace piece would have something to rest on. I then ensured the brace was level and welded it to the A frame legs.
The brace is there and is mounted on the front legs for two reasons. One, it provided mush needed stability to the legs and Two, it is mounted at the front to work as a stop, in case the gas strut fails for any reason. This will stop the top from swinging down underneath.
Mounting the gas strut
The gas strut is mounted on the very edge of the table and is mounted at a specific angle to allow for the weight of the table top to stop the gas strut from pushing the table up without being assisted. The strut I had laying around has a thread on one end which I fabricated a small bracket for it to screw into and a ball joint type mounting bracket on the other end. The ball joint end is simply screwed into the table top and the other end is mounted to the inside of the leg.
To mount the bracket to the legs, I welded a bolt to the leg and cut the end off to allow a nut and the bracket to slide over. I added the nut with some thread locker to keep it in place, slid the bracket over (with a slightly over sized hole) and the followed by another nut with thread locker. I tightened the nut just enough that the bracket could rotate between the two nuts.
Step 5: Finishing Touches and Potential Extras
After the build was complete, I lightly sanded the top with 120grit sandpaper moving to 240grit to give a nice smooth surface and wiped down the legs.
I also added a small 500x6x6mm strip of wood 50mm from the bottom, centred in the table top to rest pads, paper, etc on.
Potential extras
- I have not decided whether to paint the legs yet, if I do it will be black.
- I am also considering drilling a line of holes down either the right hand side or along the top edge to use as somewhere to place pencils/pens when I'm not using them. I use a number of different pencils/pens so this will be helpful.
- Potentially a mount for a tablet