I have relocated this thread to here,
the first part of this thread can be found in the "Work in progress" forum, titled "wip handheld mortising jig
Thankyou.
NOTE:
Some how I got the captions and the pics out of order from how I normally write it up, I ususally have the explanations above the pics, this time from the second pic, down it seems to be the oposite, the captions are below the pics.
This afternoon, I started laying out the cut lines for the two angle braces to support and make square the two plates when everything is tightened permanently.
after I cut them out, I used a flycutter to clean up the cut lines on both pieces simulataeously.
Now I need to start looking at squaring up the 90 deg. angle I first used the factory sides of both pieces as a reference, against a precision square block, to orient the pieces square with the table as they are clamped in the vise.
Now I used this fresh cut edges to reference against the precision block, to true up the factory edges. here are the two factory edges with there beveled edges, just like the factory edges of 2x4 lumber, I need to edge joint these to make a nice flat surface, on the edges.
after flycutting the edges, here is the result
a quick check against the surface plate and precision block, to assure all is machined square.
Now I am going to screw these brackets to the plates, but in order to make it easier to hold the angle brkts, when I transfer punch holes, I need to mill out a dado, in the router base plate to recieve the bottom of each angle brkt.
I need to be careful to not go too deep, or I risk cutting into the screw holes on the side,of the plate, So I set a depth to cut.
The angle piece is 1/2" thick so I use a 3/8" endmill to make two X axis adjustments to sneak up on the final width of the slot. Using the workpiece itself as a guage.
Now they both fit, so I can move onto drilling and tapping holes to bring the base X axis plate assembly together.
You may have noticed I use my drill chuck to hold my mill toolings, I have not had any problems with doing it this way, it is easier for me to change tooling. When I use end mills greater than 1/2" dia, I use my shopmade endmill holders, with the 2MT shanks, to fit my mill spindle bore. 　 have fun in the shop. 　 　 　 　 　 　
At this point I have everything screwed together for the first subassembly. the next sequence of pictures is the installment of the angle brackets. 　 It's time to work on the axis travel arrangement. I thought about 3 ways to do this, first was with a linear bearing approach, where I would ream a hole through a piece of steel to be the bearing, and make 4 of them, then make some sort of rail system out of round bar stock for the bearings to run on, however, that would mean some elaborate bracket sytem to hold the rails up, which would mean 4 rails 2 for each axis, then I thought about linear beraring surfaces, with simple rabbets cut on workpieces (guides) to be put together, to form a square channel rail system, lastly the good ole dovetail rail system, I've built quite a few projects using dovetail slides they are very efficient, so opted to use the dovetail method, for the linear slides.
Now to achieve the "X and Y" axis movement, I need a central dovetail slide block, which will have perpendicular dovetail grooves cut in it. I need a thick enough stock to do this with so 1" bar stock will suffice for this. Here the x y directions are drawn out for me to use as reference.
Now the design of this whole project is dictated, with the available bar stock I have on hand, in my metal bin, and because of that, I need to have the right sequence of machining operations, so as to not cut something wrong size. I want to start cutting the dovetail slides, however the width of this piece,
determines the distance of the x axis movement on this assembly here
and the width of this piece
determines the length to cut off this piece here which is the 'Y' axis movement,
next sequence of pics, shows the laying out of the baseplate, from squaring sides to final layout and determining placements of dovetailed guide rails. 　 　 　 Now I can start the dovetail slides, first cut the stock to rough size, then flycut all 4 pieces to get good straight reference flat edges.
and finally start cutting the dovetails on the individual rails, when all 4 are done, then the central block can be dovetailed.
The next thing I worked on was, assembling one set of dovetailed slide rails on the main baseplate, that will allow the router to travel in the "Y" axis direction.
Here I'm using again my surface plate as the datum, to ensure the fixed slide is assembled perfectly square with the front of its base plate which is sitting vertical on the surface plate.
now roughing in the size of the dovetails on the slides
I can layout where to machine the central (universal joint) dovetailed block, for its dovetails to mate into there.
I know I want to have alot of support with this central block, so I will need to machine the two ends down before I can cut the dovetails on the block.
So I marked out where the cuts will need to be,
Now before I cut out the end pieces for the dovetails, I want to machine the dovetails on the long side of the central block first, which will mate with the top router base subassembly. So I couldn't hold this in my vice, it needed to be clamped directly to the table. so some indicating in the workpiece
now the dovetail milling can proceed.
now the next sequence of pictures shows the order in which these parts will mate together, and where they will finally be located on the subassembly, which was done in the first blog installment.
I am goint to fasten the fixed slide rail to the subassembly, by tapping into the subassembly plate itself, because there is enough thickness to put a screw into for good adhesion.
I need to find the thickness of this plate
so I can set the guage to half its thickness
which then allows me to mark the slide rail itself for a ref. line to drill the screw holes for.
with the rail predrilled, I can now transfer punch one of the holes to the subassembly, for drill and tapping a screw hole.
now I have to do the opposite with the next slide rail, because the base plate is to thin
to tap into for good support of the rail here I set the central block tight against the fixed rail which now alows me to position the adjustable rail where it may be, to know where to drill clearance screw holes at.
once the plate has clearance holes drilled I can transfer punch to the slide rail,
and drill and tap the rail
here is the subassembly mating with the central (universal joint) docetail block, this gives the entire router the "x" axis travel for the width of the mortise at each location on the board.
Now I can proceed to machine the central dovetail block on it's ends to give the router it's "Y" axis travel, which gives it the depth of cut of the mortise.
　
the next sequence of pics shows the central block being machined for the "y" axis movement of the unit.
The assembly to its base
Every dovetail slide has some way of adjusting the tightness of the slide to its mating piece, to reduce unwanted play, usually a gib is used, or a slot is cut in the divetail itself to be used as a fised gib, these slides are not going to get a lot of wear and tear to need constant adjustments, so no gib will be used, however, there is always the need to lap in mating sliding parts to give the best sliding fit possible with very close to zero play, between them, so I am making one slide rail of each set fixed, and its partner an adjustable one, by elongated the screw holes into slots for making final adjustments.
That was the bottom plate, being machined, the top subassembly needs the same treatment, later on.
When I do the final asembly of the entire jig, I will use lapping compound and lap in the mating slides, then loosen the screws on the adjustables, and move them in tightly until the slide block is pinched, and again lap it in, until the slide block is so lapped in that no excessive play will show with the slide block and both sets of rails, yet they need to move in there respective coordinates very easily which is side to side, and in and out, to produce the mortises.
Here is everything mating up as a dryfit
　
　
Have fun in the shop....
　
　
　
I got a couple hours in yesterday afternoon, I started by lapping in the central dovetail block into both the subassembly guide rails, and the base guide rails, respectively,
here is one side of the block without any lapping done to it, it is rough on the top inside of the dovetail, this could have been prevented if I would have taken light cuts on the mill, however. I knew I would lapp this in, so I took substantially deep cuts, around 0.200" at a time, so the reason for the roughness.
here is the lapping compound spread onto the dovetail of the central block, I just apply very thin film of it
Here is the after lapping of one part of the block,
everything is smooth sliding, with little play, there will always be some play with this kind of sliding joint, due to the need for extreme ease of travel, by hand pressure, ususally for a dovetail slide, you want it to be almost zero play, which is where adjustable gibs are used, however, with that, you then need to move the slide via mechanical means, usualy a screw thread, because of the snugness of the sliding joint.
If I wanted a very good sliding fit with zero play I would have gone the rout of using a round bar and reamed bearings.
Now it's time to start the front fence assembly
when I placed the guide rails on the base plate, I wanted some extra space to put a substantially long support block in to stiffen the fence front with the base plate.
So after some measurements
I can start making the two support brackets.
need to check to see how it fits in with very little gap on top.
now the marking off and machining of both blocks together as one piece.
and cutting it into two pieces for each side.
Next is to attach these blocks and the front fence, then start working on the depth fence, for holding down the jig tight to the workpiece for edge mortising.
A few hours of shop time at a time, but it is coming together a little at a time.
Here is where I'm working on the front fence, I need to first cut a thru hole through the router baseblate subassembly, so I do some guaging and measuring and marking off to locate the approximate center of the router shaft.
then drill a 1/2" hole for the router cutter to come thru.
Now I can put some marker on the front fence in preparation for marking and measuring, this will be the slot in the fence to allow the cutter to move back and forth on the "x" axis, when cutting the width of a mortise.
next will be the completion of the front fence and some fine tuning on the whole project.
A couple hours more in the last couple of evenings,
Here is where I left off at after the last machining session, I was able to get some slots machined for and adjustable depth positioning fence, this allows me to adjust the depth of where to cut the mortise in the edge of a board, for example, set it 3/8" off of center to put a mortise in the edge of a 3/4" thick board ect...
Now, I'm now finishing up the details on this project, so I drew up a punch list, to start this process.
I was going to put it on top, so it can be held like a biscuit joiner, for edge mortises, however, given the material I have on hand to work with, I had to use a 1/4" thick material for the front fence, and with the depth positioning fence fastened on top, with the weight of the router, allows it to have some bend away from the edge of a board to be mortised, this can be easily remedied, by machining a small angle alignment on the depth position fence to make up for this bending in the front fence, but I decided it woulod work better if my boards were held in a vise, (my workmate) on edge, and set this jig on top, however, if I put the depth positioning fence on the bottom, I could make a clamping system to keep everything nice and tight while work is being done on the board.
So first I need to estasblish all reference points to make marks on the jig, to be used as depth fence positioning guide lines.
guide lines marked for 3/8", 1/2" and 3/4" off of center.
Now I need to make some reliefe spots to be able to better see the pencil marks on the edge of a board, so I'll machine down these areas here
the process involved
and mark out the center line for reference for lining up a board for a mortise.
Now I started the clamping system, the top block was drilled and tapped for a 3/8 -16 all thread I had in the bin,
the process in making the clamping jaw,
here is some scrap to work with,
here is my drawing of the dimensions at the lower right corner
first I need to machine a spigot, that will fit into a corresponding hole in the moveable clamp jaw.
it will go in like this
now I need to make the allthread fit into this swivel joint,
now to mark off the location to drill and tap for the setscrew in this swivel joint block.
and the process
now bore a hole in the vice jaw paf to accept this swivel joint block,
to keep this permanently affixed, I used super glue.
now a dryfit to see how it all works together.
　
Next I want to work on handles for the jig, and a "x" axis lock pin, for drilling dowel holes
as well as a plunge piston, to make it work like a plunge router.
I needed to make a latching stop block to keep the router from slipping off the back, its not only a stop block, but also a latching block, because later I will attach some sort of a latchng mechanism, on this block to keep the router elevated above the workpiece while repositioning the router for the next mortis.
Started out with a quick sketch with some dimensions that later got changed during the machining process
I also worked on making an arrangement for a "Y" axis stop, to set the depth of cut for a mortise, this feature is already built into every router base, by simple adjustments, however, depending on how long my mortise cutter will be, determines the amount of router base adjustment I can make, if I need more adjustment, then I need to make this depth adjustment feature, as well.
So I started out by making a slot to allow the sliding fit of a 10-32 screw and washer to fit into, for tightening down the stop block.
and to accomodate the washer now
now I want to start working on "X" axis stop blocks, these will be needed to set the length of a mortis to be cut.
again these a quick conceptual sketches, the dimensions get refined as I start the machining process.
two 1/4" dia. steel rods. to be machined with 8-32 TPI, to be assembled to the base of the unit.
and the machining process
and now drill and tap the base
and the assembly, these will later be cut to a shorter length, after determining where the stops will go.
now this weekend I have left off with the beginning of making the side stops. here is the process to make one stop. I'm showing the sequence of what's involved to make a part, for the enjoyment of seeing how it's done. I will say there are numerous ways to tackle a job, it depends on the tools at hand, and the techniques learned through out the course of time. For me personally this is the way I chose to do this job, here it is step by step: Again I like to start out by first making a quick sketch, of what I'm envisioning, as I machine the part the dimensions get more refined, as I see needed.
now I mark out rough locations on the work piece this part will go at, by doing this I can determine the size of stock I need to aquire the right dimensions.
Ive determined that a 5/8" dia roundbar will work for this, at around 3" long, for a rough start.
now I need to square up both ends on both pieces, in the lathe, commonly refered to as facing off the ends.
now I start to get more refined in where to machine this part, by placing it in its location on the workpiece.
Now here is where some preliminary thinking comes into play, I need to machine a end rabbet, on the part, but on this opposite end
I need to drill two perpendicular holes, as well as some slotting, so this means both ends of this workpiece, will have machining operations done on it, Now I could use a vise, or "vee" block or any kind of appropriate fixture to be able to reach both ends in one setting, however, I have a nice tooling fixture called a "indexer", better known as a "spin Jig",which indexes every one degree for a total of 360 deg. because I'm going to be machining areas on this part 90 deg. to eachother, I opted to use my spin jig. That's why I chose round bar for making this part, because my collets for this jig hold only round bar. The next process is to set up this fixture, in order to set up any fixture, to the table it needs to be squared up with the axis movement of the table, therefore I use my dial test indicator to "zero" out the fixture, by first putting in the workpiece, and taking the readings off of it, to adjust the fisture to the table, to be square..
Now I start refining the cut lines, such as the length of cut
as well as marking off the depth of cut
now back to the machining process as can be seen I need to machine this end,
but if I start machining this end imediately, I run into trouble trying to line it up back in the index jig, when I turn the piece end for end, because the other end needs to be machined in reference to this end, to line up properly on the project. This is why I have this workpiece extended out as far as I can, because I need to machine a flat reference surface as far down this workpiece to where when I flip it end for end, I can use this flat end to set up as reference, but more on that later, so now to put this procedure in order, I want to machine this reference surface, however if I machine a flat at the other side of the rabbet cut
, I risk making the end to thin after the rabbet is cut, so I need to make the flat refernce cut 90 deg. of this rabbet cut on this side,
because most of this material will be cutaway with the rabbet anyhow, not affecting the thickness of the rabbeted edge . With that in mind a first set the jig to read zero on its dial.
now I dial it 90 deg. to the left of zero, which is 270 deg.
now the workpiece is oriented 90 deg. from its original orientation when it was marked horizontally.
now using my magnifier, I line up the center of the spindle to the center of the work, and lock the "X" axis table movement.
and now the reference flats are machined to around 30 thou. depth on opposite sides.
now I can move the workpiece insede the jig to make it more stable,and have a better grip on it when it comes to machining the rabbet, this can now be accomplished with perfect accuracy, by taking a precision square block and lining it up to the reference flat, and tightening the jig to rehold the workpiece, for the maching operations to follow.
This is the first purpose for the reference flat.
now that the rabbet has been formed on one end of both workpieces, I can now line them up to where they will be assembled to on the project, to start laying out the areas for drilling holes.
That's where I left off this weekend, the next set of procedures to finish machining this workpiece will continue in the next installment.
Theres a lot of pics in this thread, which makes it slow loading, so I disregarded a lot of the progress pics from a few days ago, and today I'll show some highlights of where I am at in this build blog, I'm making handles for the mortising jig, so here are pics of me making small tapers on the handle tops, then a quick lok at my shop built tapering jig to make the long tapers.
Now I will first machine a small taper on the handle top, I will use one of the bars I just threaded as a mandrel to hold a handle top onto, then I will set up to machine a taper. Because I don't need to use the tailstock to support the workpiece, I can adjust the compound slide to the desired angle, you will see in this setup the taper is being cut the opposite way it is usually done on a lathe, however it still works.
now instead of machining a large chamfer on the front end of the handle top, I decided to just work it to a round profile usiong a file, with the lathe running.
The piece on the left was not yet worked by hand filing the one on the right is after the finish filing.
now both handle tops are finished with all the profiling
I now want to enlarge the thread from 1/4-20 to 3/8-16 tpi, on the opposite end, to give more of a substantial attachment of the handle assembly to the subbase. Here a 3/8-16 tpi. bolt is used to check for fit.
Ok now that the handle top and shaft is all drilled and tapped, and ready for final assembly, I still want to make a long taper on the shaft of each handle rod, to make for a more comfortable grip, as well as asthetics too. This taper will go from the bottom to the handle top, increaqsing in elevation, However, I want a good support base at the bottom of the handle rod, so I will begin the taper up above the very bottom, so I first mark it off like this.
Now I can machine a groove to required depth, to where the taper will start at the small end.
After determining the depth of cut in, and the length of the taper, a quick trig, calculation, shows the arctangent of 0.25, which is around 14 deg.
Now I could again set my lathe compound slide to this angle, however because my workpiece is very small, and I have a very small area of grip in the chuck jaws, I need to use my tailstock to hold this workpiece, or else it will have great deflection, and ruin the work, so the only way I can use my tailstock and still cut a long taper, is to use my shop built tapering jig. So here I have it set up as it takes the place of the entire cross slide on my lathe, and it is very easy to set up any angle I need, by using my protractor in combination with a ruler. This setup is close to the 14 deg. taper angle I need.
With everything locked down I can start cutting away the taper.
And a look at the before taper and after taper, with the two workpieces.
Now I can place the workpieces back in the lathe to rough cut them to length.
And after facing them to final finish lengths, I have the tops dry assembled to each shaft, to check for fit.
And a quick look at where abouts they will probably fo on the subase assembly, on the mortise jig itself.
That's all for today.
Have fun in the shop.
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
　
