Introduction: COVID Lockdown Inspired Table Cutter
For the longest time, I have wanted to get myself a table cutter but the price tag of around 27000 to 35000 rupees (US$ 350 to 450) seemed a bit too much. While I consider myself to be quite a DIY kind of guy, the projects I indulge in are merely as a hobby and investing that much for my weekend projects didn't seem justifiable at this point in time.
Then COVID 19 happened and India saw the worlds biggest lockdown where 1.3 billion people were told we could not venture out of our homes for 3 weeks at first and then another 2 weeks and then yet another 2 weeks.
So in week five of the lockdown, I found it to be an opportune time to collect the bits and pieces I had lying around at home and attempt making a table cutter of my own. The week or so that it took me was long, having to think out of the box to come up with ingenious solutions to work with what I had. Buying spares was not an option due to the lockdown.
Here is how I went about it.
To start with I had some length of GI (Galvanised Iron) pipes (leftovers from some garden fence work I undertook earlier), I had a motor along with a starter mounted on a stand from another project which was not being used.
Step 1: Materials Required for Build
Other than the pipes, the motor and starter I mentioned previously, I knew the following would be required:-
(a) Plywood 5 feet * 4 feet
(b) hinges fro the table top
(c) U clamps for the cable holders
(e) one MS bolt of 1 inch dia and matching set of washers and nuts
(f) limit switch for additional safety cut off (optional)
Tools required would be
(a) Bearing remover tool
(b) Welding set and accessories
(c) Angle grinder/ cutter
(d) Tile cutter with appropriate blades for cutting wood
(e) Power drill with drill bits of varying sizes and circular hole cutters
(f) Protective gear - ear muffs, safety goggles
I am not going to be specifying the sizes (lengths to which i cut the pipes as it may vary from depending on the size of motor and items the readers may have)
Step 2: Build Step 1 - Basic Table Design
Step 1 was to cut out the pipes to the required length and in my case one of the four pipes fell short by a few centimetres and it was of a different diameter. This (maroon coloured) pipe was of a different diameter. This was made good by attaching a small piece of the smaller diameter pipe like the other three to the top of it.
This was important to ensure the four pipes that were to form the legs of the table could offer uniform support to the table top. The table top itself was made from four rectangular blocks as shown in the diagram and it was merely drilled to half its thickness with a circular hole cutter (as shown). This cut portion would be made to rest on the pipe (legs) of the table.
The pipes were welded together to gradually form the legs and support for the table top.
Then there was the a few rectangular GI pieces cut to length as shown which I intended to weld at about the half way mark between the ground and the table top to provide additional strength and stability. On this welded member, I had plans to mount the motor base (also shown in the picture).
The next step was to cut out the ply wood piece to an appropriate size and fix two strong stainless steel hinges along the longer side and screw the hinges to the edge opposite to the side where the operator would stand. (as in the picture)
Step 3: Build Step 2 - Getting the Motor and Starter Mounted
Step 2 - was aimed at mounting the motor and also welding the bracket for the starter panel on to one of the legs of the table at a convenient height for the operator to use.
Prior to mounting the motor, I took a day to paint the motor, the starter and the starter mounting bracket with some black paint (that I had from earlier) and in contrast, I used yellow colour to contrast with the black. Nice touch as I later realized.
To mount the motor, I had to first mount the base plate onto a wooden piece and bolt the wooden piece onto the rectangular GI members welded at the end of step 1.
Ensure the motor is secured as tightly as possible to avoid unnecessary vibrations - considering the 1 hp motor rotates at close to 1800 rpm.
Once in place, I had to remove the existing pulley on the motor shaft to make arrangements for the blade. For this I had to employ a motor bearing removal tool - something that I bought for 400 rupees. - My first cash investment for this project.
Once the pulley had been removed and it took a bit of effort to do so, the next step was to make and arrangement to fix the rotary blade
Step 4: Build Step 3 - Making a Blade Securing Arrangement
Step 3 - was perhaps the most challenging part of the entire build.
I wanted the design to be such that it offered the ease of maintenance. With that being the main goal at the back of my mind, my intention was to make a securing mechanism for the blade that would preferably be easy dismantle and in the worst case scenario allow for the motor to be rewound if need be.
That automatically meant I could not have anything of a permanent nature fitted onto the shaft as rewinding the motor would require for the top cover of the motor to be slid off the shaft. Therefore anything obstructing this cover removal had to be avoided at any cost.
My original plan was to weld the bolt head of a 1inch diameter mild steel bolt to the end of the shaft. However with the bolt's hexagonal head being much larger than 1 inch, this would get in the way of the motor's front cover being removed (for rewinding) and therefore I had to discard that idea.
The next idea revolved around securing the nut for the 1 inch bolt onto the motor shaft. This meant three major challenges :-
(a) The motor shaft did not come with any threads and so threads would have to be made and I did not have a tapping / die set for this job
(b) The thread and mounted nut had to be exactly concentric to avoid wobble and related vibrations (which would get amplified many times over with a 14 inch rotary blade)
(c) I had to find a appropriate washers to hold the blade tightly in place once the nut/ bolt assembly was put in place.
Though I did not have a thread die tool set, I tried to try something unconventional with an adjustable spanner to hold firmly the motor shaft and a vice (for want of another adjustable spanner) to hold the nut in line with the motor shaft. Starting with a gentle hammering on the nut onto the shaft and lot of turning clockwise and counter clockwise a number of times, I successfully cut three threads. By some luck managed to get it on without being eccentric - yes that is the right word for NOT Concentric ;)
With challenges (a) and (b) above overcome, (c) was straight forward only that I did not have one washer of the required diameter. Fortunately I had some washers with inner diameter of 1 inch and 1.5 inches and sure enough welding them gave me the washers I required.
Lastly I measured the lenght of bolt that was required to secure the two washers, the blade et al and cut off the extra length. With all in place and secured I turned on the motor and it turned and thankfully without much wobble.
Before disturbing the arrangement I made a couple of spot welds on either sides of the blade between the bolt and washer on one side and between washer, nut and two small spots between the nut and the motor shaft.
This way if I ever wanted to removed the nut on the shaft all that was required was cutting two spot welds on the shaft.
Step 5: Build Step 4 - Finishing Touches
Step 4 - was where the finishing touches came in.
I cut an appropriate slot for the blade to pass through the ply wood table top and cut another slot at right angles to serve as a guide way for the rip fence (I believe that is the term).
To ensure the rip fence travelled along a straight line, I made a guide with two bolts protruding above the surface of the wooden piece - one long bolt which would go through the ply wood and through the rip fence and a securing handle assembly. where as the second bolt (much smaller) would merely act as a guide along the path. (see picture).
Lastly I thought it best I fix a limit switch as well to cut off power supply should the table top be opened for any reason.
At the end of a long one week, I am happy to say I have successfully made my table saw and all in all it cost me a fraction of what it would have cost me to buy a branded one.
Of course this is no Bosch or Black and Decker and it does not come with a tiltable option either.
What matters is I think I have what I need to help me with my DIY work going forward.
Please send me your comments on how I could improve the design further. And given the trying times we are all going through Stay safe !!
Participated in the
Scraps Speed Challenge