One Belt To Rule Them All

The metal lathe I purchased used was in good condition, but there were a couple things that needed attention; one was cleanup, and the other was belts.

I focused first on cleanup. I took the various slides and screws apart, cleaned them off with mineral spirits, re-lubed, and re-assembled.

That was a nice task to take on, because it introduced me to the various parts of the lathe and gave me a better feel for its construction, capabilities, and limitations.

The next issue was that of the drive belts. My lathe came with one belt, but needs three in order to have full range of speeds.

The manual listed their sizes: 0-710, 0-800, and 0-900. Great! So I did a search online for belts of this size, and found… links to the manual for my lathe!

That’s right: Harbor Freight had managed to use belts on this lathe that no longer exist in reality.

Just in case this was a fluke, and the internet was defective, I went to the local auto-parts store and showed them the sizes to see if they could find something similar, and they could not.

I called Harbor Freight technical support, and spent a long time waiting while they verbally scratched their heads, and then they came up with the answer: 710, 800, and 900 were the size of the belts in millimeters! (that may have been obvious to you metric readers, but I live in America, the God-Blessed land where measurements are based on thumbs, grains of wheat, and historical monarchs’ feet (hey, you started it, England))

So I converted millimeters to inches and ordered three v-belts from my favorite supplier (locally based so  they ship very quickly), and tried to put them on my lathe.

Not one of them fit.

I could almost get the smallest one on, but it was so tight I nearly lost fingers in the process. All three pulleys are in fixed positions, so I couldn’t shift them to loosen or tighten the belts.

Oh well, I thought, at least I know what sizes to order next, so I bought two more larger belts (I decided that I would only buy two, and continue using the old belt as well).

Failure!  These belts were also too small!

I had now accumulated $30 worth of belts without successfully equipping my lathe.

Metal Lathe Belts - Failures

After this, I took a different approach. V-link belts are a favorite for woodworking equipment because they don’t have as much memory as a standard solid rubber belt, and so lead to less vibration and smoother cuts.

I have one of these belts on my table saw, and while I haven’t seen an appreciable improvement in the quality of my cuts, I like the belt because I can adjust its length fairly easily.

These belts tend to be expensive. $7-9 per foot, or $30-40 for a 5-foot loop.

I found mine at Harbor Freight. It’s a name-brand product, so it’s still not cheap, but $25 for a 5-foot loop and then a 20%-off coupon means it’s $20 and a lot cheaper than anywhere else, and I could use the 5-feet plus a few extra links from my table saw to make both the belts I needed.

Metal Lathe Belts - Solution
After picking up a belt on my lunch break, I spent 10 minutes tweaking the length of the belts and getting them fitted.

They fit. The pulleys turn. The Lathe cuts. Done.

Metal Lathe Belts - Installed

Why don’t I always try the obvious solution first?

Table Saw Dust Collection Concept

The Rockwell 10″ Contractor saw I own has an open frame and an external motor hanging off the back, making efficient dust collection an issue because controlling the airflow is next to impossible.

I have a friend with a similar saw on an open frame, but his saw’s motor is more contained, so he doesn’t have the challenge of  plugging a hole that allows the motor to pivot as the blade is tilted to make a beveled cut.

I may still try to close off the cabinet and plug the holes to set up a more traditional dust collection arrangement, but I have an idea I’d like to try out first

Here’s what I’m thinking: I might be able to get effective collection by attaching a “fender” of sorts around the blade under the table. If I attach this fender to the arbor assembly (similar to how I have mounted the riving knife) then I can keep it in close proximity to the blade, which should make for very effective dust  collection.

I made a concept drawing in Sketchup to work through some kinks in my mind:

I like the idea, but I still need to figure out if it will be practical to mount this to the arbor assembly to have it move vertically with the blade, or if I should just attach it to the horizontal rails so that it will tilt with the blade and motor, but will not respond to the depth of the height of the blade.

I’ll keep you posted.

Table Saw Extension: Plugging the Hole

When I doubled the size of my table saw by adding a second table top from another old saw, I had a hole in the middle of the added segment where the saw blade insert would have gone originally.

I thought about making a blank insert to fill the hole, but then I thought I could make it more useful but using it as storage for my stock insert, which I will use when I need to make beveled cuts (my zero-clearance insert prevents tilting the blade, so I need to swap the insert if I need a beveled cut).

Since the stock insert is a relatively thin piece of metal, I partially filled the hole with a piece of 1/2″ plywood so the insert would sit flush with the surface.

I had to drill out the plywood under the insert’s holes because the underside of the insert is bent downwards around these holes (basically the negative of the countersink in the top of the insert) causing the insert to sit a little too high.

After drilling the holes, the insert sat a tiny bit too low, so I shimmed it up with a few pieces of duct tape.  I also used a Sharpie to color the wood under the openings in the insert, just to make it look a little better when it’s all put together:

Now I have a place to keep my stock insert, and I don’t have a big hole in my table saw top:

So pretty.

Now I need to make something with the saw…

Table Saw: Support and Storage

My table saw is huge… but unstable.

I noted near the end of my previous post on the topic, that I would need to revisit the saw, since it is top-heavy and in danger of tipping to the right due to a lack of support under the expanded table top. So that is how I spent my free time this weekend.

I wanted to continue using my table saw’s mobile base, so I needed to find a way to extend it to support the far-right end of my table. I decided the best way to do this would be to install a plywood floor in the mobile base and then install a support from this floor to hold up the right end of the saw.

For some reason I thought 1/2″ plywood would be sufficient, so I measured out and cut the necessary pieces with my circular saw (I used an offset straight-edge to guide the saw).

I was planning to use some angle iron to extend the mobile base frame, but was having trouble figuring out how to attach it to the existing frame without having to redesign the whole thing.

I was also starting to realize that the 1/2″ plywood was far too thin to make a stable floor for the saw, as it would bow significantly in the middle (the mobile base only supports the corners).

To solve both of these problems I figured I needed a rigid floor that I could simply attach the ends of the mobile base to, instead of trying to make the mobile base itself support the length of the floor.

I happened to have a piece of 3/4″ plywood on hand that was about the right size, and I screwed it to the bottom of the 1/2″ piece I had already prepared. This alone was pretty sturdy, but I decided to further reinforce it by attaching the angle iron to the sides.

This made for a very solid floor that did not bend at all when I attached the mobile base ends to it and tested it by standing in the middle.

After wrestling the saw onto the base, I secured it by clamping it down with pieces of plywood screwed to the main floor.

In order to support the right end of the table, I built a box out of the 1/2″ plywood to act as a single leg.

I glued and brad-nailed the box together and installed it with a combination of glue and brad nails on the bottom and an angle iron bracket on the top.

The table saw is now fully supported and the extra space on the right side is perfect for housing my compound miter saw (I had considered putting my shop vac here, but then I bought the compound miter…). I’ll probably put a shelf above the miter saw to keep other miscellaneous tools and scraps, but that can wait. For now I am happy that I have sturdy table saw with enough surface area and fence capacity to do anything I need to (and plenty of things I don’t).

Note: In the pictures the saw appears to be leaning to the right, but this is mostly an optical illusion, and partially because I should adjust the feet of the mobile base, but a slight tilt toward the fence won’t impact performance or stability, in fact, it might help both.

The Incredible Expanding Table Saw

I have mentioned, in the past, my addiction to Craigslist. At this very moment I am waiting to hearing back about a JET pen lathe… but I’ll write about that if the seller calls me back.

This post is about my table saw. I picked it up originally from a Craigslist seller in semi-working condition for a mere $50, figuring it was worth the investment even if all I got was a pastime for a week or two trying to get it into shape.

More recently I noticed someone posting the same saw (well, the Delta version of my Rockwell saw), in much worse condition, without a motor or a fence, and missing its stand, for $300.

This was an absurdly high price, so I just laughed about it. A couple weeks later it was reposted for $200; and then again in a similar amount of time for $150.

At this point I decided to reply to the add, telling the seller about the deal I had gotten and that he would probably need to lower his price to move the saw. His reply: “$50 and it’s yours”.

At first I just laughed about it. I didn’t want the saw, I was just trying to help the guy out. But the more I thought about it, I began to feel like I might actually buy it. My rationale was this: It had its original stamped steel extensions, which I like better than the aluminum ones, and what if I could use the second table top as an extension as well?

The best extension wings you can buy are precision ground cast iron, so why not bolt a precision ground table top to the side of my existing top? Plus there was the chance I might need a replacement part at some point in the future… who knows?

So, I bought it.

It was in pretty rough shape, very rusty, but the wings were still straight.

I started working away at the rust with steel wool, but quickly moved to 150 grit sand paper on my random orbit sander.

I can hear you wincing and judging me. After all, the people on the woodworking forums all say that you’ll screw up your top with anything more than light wet-sanding with 400+ grit sandpaper.

However, on the metalworking forums, they seem to think you have to be very intentional to screw up a cast-iron surface significantly; and I wasn’t about to invest several weeks of elbow grease (yes, elbow grease is measured in time-based increments) in a cast iron top that I had picked up for $50.

I am happy to report that the sandpaper did not do any measurable harm.

The rust on the other hand…

The surface is definitely pitted and etched, but I think that it is acceptable over all: wood moves across it easily and stays flat and stable.

I treated the extension wings to the same process and got the same results.

So I had a usable set of extension wings and a second table for very little money and a few hours of elbow grease.

If you have read my post regarding my New table saw fence then you’ll recall that the space between the flush-mounted front and back fence rails was too narrow to fit my old extension wings. It was also, apparently, too small to fit the new extension wings and the new table top. This is due to my Rockwell table having a small “step” inwards about 1/2″ below the surface.

So even though the actual surface size is identical on the Rockwell and Delta saws, the fence mounts differently. So I removed the fence rails and re-installed them with a couple of washers stacked beneath each mounting bolt. This brought the fence out to the right width and allowed me to install the “new” extra wing and table top after drilling holes that lined up with the mounting holes in my fence rails.

One additional modification was to drill out the threaded mounting holes on the new table top. This was to allow me to pass a bolt through them and into the extension-mounting holes on my saw top (luckily these lined up perfectly)

The end result:

I’ll be making a blank insert to cover the hole for the non-existent insert on the second top. I had also thought about filling the extra miter slots with some aluminum bar stock I have, but I’ll wait and see, I can imagine it being useful to have extra miter slots.

I will be building a plywood cabinet underneath the new table, just to make sure it doesn’t tip over, and I’m thinking this may be a great place to house my shop vac.

So it’s not quite this:

But it’s as close as I’ll get with $100 worth of Craigslist purchases and an aftermarket fence.

Oh, and the guy emailed me back about the JET pen lathe: he already sold it to someone else. (I should have been checking Craigslist more frequently)

New Table Saw Fence

My table saw is an old Rockwell 10″ contractor saw, which is an excellent saw, but one of the first things people tend to do with these saws is upgrade the fence.

The factory fence tends to be difficult to keep parallel to the blade, easy to push out of alignment, and has a limited capacity (the maximum distance between the fence and the blade is about 24″, so longer cuts require using the miter gauge or making the cut freehand).

One of the previous owners of my saw knew this, and so upgraded the fence… to a factory fence from a different saw. I’m guessing his buddy had a saw with a slightly better stock fence, and gave him the stock fence when he upgraded to a better one. The “upgraded” fence on my saw had a better cut capacity, but was still difficult to square and easy to push out of alignment, and the rails were too tall, causing them to interfere with my miter gauge (the top of the guide rails were higher than the bottom of the miter slot). So upgrading the fence was still on my to-do list.

I had been researching tables saws ans fences and I knew that the gold-standard for accurate fences was the Biesemeyer T-Square fence, but these are expensive, and although I use my table saw often, I am not a professional cabinet maker, so I couldn’t justify buying one of these fences.

After reading reviews and comments on all the t-square style fence systems I could find, I settled on the Delta 36-T30 30″ T2 Fence System, and found the lowest price on Tools-Plus.com.

I used the new Amazon.com Universal Wish List plugin for Chrome to add the fence to my wishlist, and my lovely wife bought it for me for my birthday.

Some of the negative reviews for the new fence had complained about having to drill new holes in the fence rails to install it on their table saw because the pre-drilled holes did not line up, so I was expecting to put some effort and ingenuity into this installation, but first things first, I had to remove the old fence.

The old fence was fairly simply installed. Its rails consisted of parallel tubes on the front and the back of the saw, separated from the table with spacers (the spacers came in to play later in an unexpected way) and bolted directly into threaded holes in the edge of the cast iron table top. I think just removing the old fence was a significant improvement.

Upon removal I noticed that the holes in the table top were significantly larger than the remaining original holes. The previous owner had drilled out the original holes and re-threaded them to fit the “upgraded” fence, so I now had holes that were too large for the mounting screws that came with the new fence. But I figured I could find a way around this.

The new fence came with a large number of screws, washers, nuts, and bolts, and when I read through the directions, I couldn’t find a need for all of them, so I decided to just use them as I saw necessary and see if I could make the fence work without drilling any new holes.

Luckily, although the holes in my table top were too large for the mounting screws, they did line up with the holes in the fence, and I was able to put a nut of the back side of the hole in the table top in place of the threads in the cast iron itself.

I then adjusted the rail until it was parallel to the table top and started working on the back rail.

 

On the back, for whatever reason, the bolts for mounting the rail were the correct size to thread directly into the larger holes left by the old fence. I was happy about this but ran into a new problem: I didn’t have the required 8mm Allen wrench to tighten these bolts.

I dug through my tools and scraps and eventually found a small nut that perfectly fit in the head of the bolt. I mounted the nut onto a small bolt and tightened it down with a slightly larger nut.

This assembly acted as an adapter: the 8mm nut fit into the 8mm Allen bolt, and the 9mm nut fit into a 9mm socket, so I could ratchet the bolt into place.

After finally installing the back rail, I checked it for parallel before moving on to the next step.

 

I had intended to re-install the extension wings, but at this point I realized that the spacers (mentioned earlier) that held on the old guide rails, were not used with this new fence system, and so the distance between the front and back rails was too small to fit extension wings.

This was disappointing, but I have been considering making my own extension wings, so I figured I’ll just make that my next project and set the old ones aside for now (I may add some washers to the rails as spacers to allow the wings to fit, but I haven’t decided yet, since I don’t really like the open aluminum wings much anyways.

The next step was to install the guide (square tube) for the fence itself. This was fairly simple, but the trick is to make sure it is parallel to the rail it is bolted to (and thus parallel to the edge of the table top). By tightening down one end, and taking a measurement, and then adjusting the other end to match, getting the guide parallel to the rail.

 

The remaining steps were fairly quick, and involved setting the fence in place, adjusting the various set screws in the fence until the fence was parallel to the miter slot and blade and square to the table top, and calibrating the measurement indicator. On this last step, I realized that my fence system was 2″ too far to the right for the attached measuring tape on the guide, so that when the fence was against the blade, the indicator was 2″ to the left of zero. The only way to fix this is to move or replace the measuring tape, and since I’ve seen adhesive measuring tapes before for pretty cheap, I’m not to worried about this for now… but it is a little sad.

 

Despite the various complications, I was able to complete this installation in about an hour, and the result is a sturdy, accurate fence that is easy to adjust and a big improvement over the fence the saw had when I bought it.

Zero-Clearance Insert

After completing the riving knife modification, I needed to replace the blade cover insert to accommodate the knife’s position behind the saw blade.

I had been using the stock insert, which has a full opening to accommodate a dado stack. This setup does not support the wood fibers along the edges of the cut, and will allow tearout along the ends of the cut pieces, resulting in a frayed edge on the final product, particularly when cutting across the grain.

A zero-clearance insert has a slot that is only as wide as the blade itself, and thus the wood fibers are fully supported all the way up the the blade itself (almost as if with a pair of scissors), making for the cleanest possible cut.

Not only are zero-clearance inserts preferable to factory inserts, they are the easiest type of custom insert to make since the slot for the blade is created by simply cutting through the blank insert with the blade installed in the table saw.

I started with a set of phenolic zero clearance kit from Rockler. This kit is about $30 and contains two rectangular blanks from which you can cut inserts to fit your saw. I could have purchased a pre-shaped insert but they are more expensive ($30 for one insert) and this seemed like a fun project.

Per the instructions that came with the phenolic blanks, I started by tracing the stock insert and cutting the the blank close to the final size. The instructions recommend using a band saw for this cut, but I don’t have one yet (regularly refreshing my search on Craigslist) so I used my scroll saw. This was marginally successful, but I burned up a good blade and the blank was jumping all over the place. Honestly I think this step would be better handled with a hacksaw if a band saw is not available, or at least by switching the blade on the scroll saw to one without any reverse teeth.

The idea of the first step is to leave minimal material for the the router bit to remove in the next step, which is to use a copy-bit and the stock insert to finalize the shape.

I used turner’s tape (fancy double-sided tape) to attach the stock insert as a template to the rough-cut blank and used a 1/4″ copy-bit on my router table to remove the extra material and bring the outer diameter of the phenolic blank to its final shape.

I almost had a minor disaster while doing this. I noticed a slight change in the sound coming from the router bit, so I shut off the router and realized that I the bit was slowly lifting out of the collet and was begining to cut into the metal of the stock insert. There was no visible damage to the router bit (Carbide is tough!), so I re-seated the bit and really tightened it down. I was able to finish the routing without any other issues. On a side note, I’m now convinced that I need to set up some dust collection on my router table…

The phenolic blank is thicker than necessary for my saw, so I set up my drill press with a large forstner bit to remove enough material for the insert to sit flush.

Once I had achieved the correct thickness, I drilled out and countersunk the holes for mounting the insert.

I stripped out one of the screws while testing the fit, which gave me a chance to use a screw extractor bit that I had never tried before.

The extractor worked well enough, bit it really guts the screw so I cut a slot in the screw to re-use it as a flat head until I find a replacement.

After this, I re-installed the blade on the table saw and cut the slot in the new insert. This had to be done in 3 stages:

      • I very cautiously lowered the insert on to spinning blade to remove enough material be able to set the insert fully flush with the table top with the blade installed. Since the insert is unsecured, it is very important to do this slowly from BEHIND the saw. This way if the insert is ejected it flies away from you. since, at this point in the process, the top of the insert is completely symmetrical, I actually started cutting with the insert backwards and had to flip it around and start the cut over:
      • I secured the insert and raised the blade with the table saw running until the blade reach its full depth:
      • I extended the cut to make room for the riving knife. I actually did this with a hand saw, Stanley FatMax:

With everything finally installed, I quickly cross-cut a piece of rift-sawn white oak to see what sort of cut quality I would get. I made the cut freehand, with the blade set too deep,, but still got a decent quality cut with minimal tearout.

I’m happy with the results, and I am done with this project.

Table Saw Riving Knife modification

A few months ago I picked up an old Rockwell 10″ contractor saw that needed some work which I got up and running pretty quickly. Up until this point I has only used cheap portable table saws (my current saw was a $250 Ryobi), so moving to the 1.5 HP, belt-driven, cast iron contractor saw was a big upgrade; but even though it was a more stable and accurate tool (and thus less dangerous to use), I found myself nervous about using it, fearing a catastrophic kickback despite never having having this problem with any prior saw (perhaps my fear was due to all of the horror stories and warnings I read while researching how to restore the Rockwell).

I’ll make another post that goes into a little more detail about the saw and the repairs I made, but for now I’ll focus on my most recent modification: adding a riving knife.

A bit of background: A riving knife is essentially a fin behind the blade that rises and lowers with the depth of the cut. It is approximately the same width as the blade and helps to keep the material in line with the blade after it is cut.  It also helps to prevent the freshly cut material from pinching the back of the blade, which can result in dangerous kickback and serious injury. Most American saws have featured a “splitter” type system, which places a fixed fin a few inches behind the blade. Riving knives have been standard on European saw for some time, and are now standard in high-end table saws (American or otherwise). Splitters are better than nothing, but since the original splitter was missing from my saw, I decided to see if I could add a riving knife instead.

I started by tracing my saw blade onto a piece of 1/8″ aluminum plate and drawing a knife shape that would closely follow the blade and then cut it out with a jigsaw.

My saw is set up with a thin kirf blade, that measures about .0925″, so I knew I would have a bit of metal to remove before the blade would be the correct thickness.

kirf width

I worked on it for a long time with my grinder, sander, and hand file, but was still too thick, and was having trouble maintaining consistent thickness along the blade

.knife thickness

At this point I did a little more research on the appropriate width of a riving knife and found out that the goal is not to necessarily match the kirf width, but rather to land somewhere in between with kirf width and the blade plate width, since the purpose of the knife it to keep the wood from grabbing the plate. My blade plate width is .0745″ so anything in between .0745″ and  .0925″ would be fine.

Blade plate thickness

I went to the local metal supply and picked up a new piece of aluminum that id 0.09″ thick, that I will be making the new knife out of.

Since, at the moment, my wife and daughter were taking a nap and I couldn’t use any loud tools (i.e. the jigsaw) to cut out and shape the new blade, I used the existing blade to finish the construction of the mounting bracket for the knife within the saw itself.

I had already cut the basic shape of the mount out out 1/4″ aluminum and refined the shape by clamping it in place with a pair of vise-grips and raising and lowering the arbor assembly to see if the mount interacted with and of the other saw components. My final shape is shown below:

Riving knife mounting bracket

This right end is designed to mount to a flat surface on the arbor assembly that is parallel to the blade. I drilled (using my cordless (read: “quiet”) drill) and tapped the flat surface in the arbor assembly to match the three holes in the right end. The two holes on the left end are placed to thread in screws to mount to blade itself.

A test fit showed everything to work properly:

Mounting bracket test fit

I then removed the bracket and attached it to the knife using a couple of nuts as spacers to bring the knife directly behind the blade:

Riving knife assembly

I was then able to install the full assembly and test the movement:

I am happy with the movement overall, of course I will need to finish the second knife before I can test it, but since I won’t need to adjust the thickness of the new knife, I should be able to finish is pretty quickly.

I may also revisit the knife length. You can see in the video that the blade comes up before the knife, and if only parallel to to the top of the blade when the blade is at full height. This means that the knife will not be present in shallow cuts. This is not a problem on newer saws because they are designed with a fairly complex system of linear slides that keep the riving knife in the same position relative to the blade.

Since my saw raises the blade by swinging it along a radius, and my riving knife if effectively an extension of the arbor assembly, it is moving on a larger radius, so each degree of movement is exaggerated in the riving knife relative to the blade.

I can resolve this my making the riving knife longer, but with the consequence that the riving knife will be over the top of the blade when the blade is at full depth. I haven’t decided which problem is worse, so I’ll have to update you with the results of further experiments.

Video of the full process below: