Straight Edge Clamp Saw Guide

Track saws are one of the hot new things in woodworking. I guess they have been around for a while, but it seems like every power tool company has jumped on the bandwagon. They look handy and appear perform nice clean cuts with the way the track backs the saw blade. They are all really expensive though.

A cheap substitute is to use a clamped straight edge to run your saw or router up against. It works, but doesn’t prevent you from wondering away from the guide and doesn’t back the cut. I have a few clamping straight edges from a company called E Emerson. They sell a saw plate to attach your own circular saw to their track, but it has abysmal reviews and doesn’t back up any of the cuts.

Instead I am going to 3D print an adapter to hold a sheet of 1/2″ plywood to act as a moving saw plate base. I took a pile of measurements and after a few iterations came up with the right design that would hug the tracks available on the clamp.

I had some phenolic faced plywood left over from making my own table saw inserts. I cut the plywood to the rough size of my circular saw base, and attached two long guides.

To attach the saw, I tried printing some different bracket styles, but was never happy with how they held. Instead I found a 1/4″-20 threaded hole in the base near the front to take advantage of (I think it was for some kind of moveable crosscut guide you could buy), and just drilled a hole in the back. It worked out though, the ribbing in the saw plate holds a nut perfectly. I counterbored holes in the bottom to keep the screw heads from interfering with the plate’s movement.

The saw is well fixed now and ready for me to plunge the blade through. With this setup I cut a slot that is perfectly sized for the blade. Now any cutting I do will be well supported and have little to no tear out. It is like a moving zero clearance insert.

It just so happens that I had a full sized sheet of plywood that required crosscutting down to reasonable sized for a project. Here is the setup ready for its first cut.

Everything went smoothly until I got to the end. The guides got hung up on the folding clamp lever (blue and pointing downward in this picture). It left me with a few extra inches of plywood still left un-sawed. Kind of a bummer.

I regrouped and decided to move the front guide back until it touched the rear one, this would buy me a little. It still wasn’t quite enough, and some heavy sanding was required. Once I shaved it down at an angle I was able to make a complete cut across the plywood.


Once I got the cutting part figured out I wanted a set of guides. Setting up one of these straight edges always involves a bit of math. You need to know the distance from the blade to the edge of the saw plate, and are you concerned about the inside or outside edge of the saw kerf? I made a set of plywood blanks that show exactly where your cut will land. Now you can make a mark. line the blanks up, and voila. Just line it up and that is where the cut will happen.

I made a number of different length guides all designed for 1/2″ plywood and uploaded them to thingiverse.

TPU Printing Tips

Printing flexible filaments holds a mixture of horror and delight. On one hand making something squishy and flexible allows for custom grips, cushions, dampers, and all sorts of fun wiggly toys. On the other hand it can print like a nightmare. I had enough bad experiences early on I nearly completely swore off printing flexibles. Eventually I had someone requesting some flexy parts, so I got back into it.

Most printable flexible filaments are either TPE (Thermo Plastic Elastomer), or TPU (Thermo Plastic Urethane). TPEs tend to be a little softer, but you can print a structure with more infill to make it stiffer, or less to make it more complaint.

Problem 1: Bed Removal

Normally when 3D printing it is a hurdle to get things to stick to the bed. Not so with TPU. It sticks to the bed sheet material with such fervor that it will actually peel the PEI layer off the bed. I did this in the past and was upset about it. I found spreading down talc powder helped, but never fully alleviated the issue. Then along came my little purple friend.

I have heard people talk about glue sticks to help print adhesion. I never had any luck with normal hard plastics. But it acts as kind of a barrier or release agent with TPU. Sticky enough that it won’t come off during printing, but soft enough the part can be peeled off. It builds up over time, but is water soluble, so just wash it away in the sink. A thing layer is all you need. I never heat the bed when printing TPU.

Problem 2: Loading

Once I tackled the removal issues a little while back I was happy to perform occasional prints. Loading flexible filament could be a pain though. Half the time it would jam and wrap around the extruder. I did some reading and experimenting and came up with a two part solution.

When loading, increase the temp 10-20 degrees. It makes the TPU flow better. My Prusa has an automatic filament loading function. It detects the filament, loads quickly, then slows down to extrude new filament and flush the old residue. That initial quick load gets me in trouble about half the time. Instead I insert the filament, but not all the way to the extruder gear. I let it perform the fast load, then push it in the rest of the way when it slows down. It hasn’t jammed yet using that method.

Problem 3: Stringing

My TPU prints had crazy stringing. It was annoying, but a set of side cutters would take care of it. I was just so happy to be printing flexible materials I didn’t care at first. Now I am annoyed at the post process work required. I started googling and came up with some things to try.

First up, a number of places talked about the flexible materials not working well with retractions. It is flexible and might jam, but I thought that would make the stringing worse. Sure enough, it was a lot worse.

My original settings were what came with the Prusa Slicer. No retraction caused considerably worse stringing. Ok, how about instead we lower temperature, that was supposed to help out.

Sure enough, that worked. It makes sense, the stuff wants to solidify faster. I checked the manufacturer of my filament, and 240C is a little hotter than they suggest. I tried one at 220C, but was starting to get poor layer adhesion. I also slowed down the retraction speed from 35mm/min to 20. Some stringing still exists, so I will try to retract further.

Even better! There are some nubs left (hard to see with black filament), but this is so much better than before. I will call this good for now, but might go back in the future and do more turning.

While I was testing these I was slowly increasing my initial Z off set. They were coming off the bed more easily with 100um of increased Z height without significant impact to the bottom layer quality. It turns out you can alter the first layer Z height in the slicer, so I made that change for my flexible material profile.

Summary:

TPU sticks too well?

  • Use a layer of purple glue stick on the print surface, it acts as a release agent
  • Increase initial Z height so first layer doesn’t get pressed in so hard

TPU strings badly?

  • Reduce temperature till you have layer adhesion or jam issues, then back up. Lower temps have less stringing.
  • Longer retractions at slower speeds might be needed.

What does one print with flexible material? Well Those test prints were feet for my macbook laptop. The originals keep falling off and getting lost, so I have been printing new ones and gluing them on.

Speaking of feet, I printed a set of vibration damper feet (thingiverse link) for the printer. The first set looked so ugly I figured I had to spend some time tuning to get rid of all this stringing. The before and after tuning results are pretty dramatic.

Other fun prints are a set of flexible hex bit holders (thingiverse link). They grip well enough to keep the bits from slipping out, but are easy to insert and remove. I tried making a set from hard plastic, but they just don’t compare.

Lastly the support arm on my tablesaw had a rubber guard to keep you from catching the edge. It got lost ages ago and and I have found it to be very uncomfortable when impacted at walking speeds. I made a push on flexible cap, but it too got lost after a few months. This one bolts into place in such a way as not to interfere with the fence. I bet I won’t be losing this one. Hopefully I won’t be racking my hip on it either.

April 2019 Prints

RTIC Tumbler Handle

For some reason RTIC has changed the shape of their 30oz tumbler. Not sure if YETI did this, and they followed suit or what. I suspect it is a plot to sell more handles and accessories. As it stands, the old handle I designed doesn’t fit on the new style of cup any more. The taper angle and diameters are just a little different.

My old handle was printed in 2 parts because most low end printers (including the one I owned at the time) couldn’t print something that big. Now a days at least a 6×6 bed size is pretty bog standard. This new design will be all one piece. The cup is large enough in diameter that getting my calipers on it wasn’t going to work. I printed some rings of different diameters and used them to estimate the taper angle of the new cup.

With that figured out I just printed a new handle that looks a lot like the old one, only with slightly more finger room and a longer grip. Thingiverse link

Drawer Pull Centering Jig

I picked up a Kreg cabinet handle jig for one of my recent projects, and because handles are something you install pretty frequently. It is certainly possible to do them well without a jig, but that always makes repetitive work easier. The jig does a good job of setting the height and width of the holes. It doesn’t center them on the drawer though. I made a few add ons to help with that.

I took a length Kreg track that you would normally imbed into a table to make moveable hold downs. Instead, this becomes part of the top fence used to set depth. Now with a spacer it registers across the whole top edge of the drawer. That also lets you use an edge stop. Now it is all centered. Once set you can put handles in the same drawer position over and over again with no more measurements or adjustments. The only downside is that there was a scale on the back of the jig for setting depth. That no longer measures true because this vertical stop doesn’t register where the old one did.

Router bits

Storage and organization is a place where the printer continues to be endlessly helpful. I have had this nice router bit set for years, but always had trouble getting the bits back in their slot. They end up clanking around the drawer and taking up more space than they should. A simple printed tray gives them each a home and takes up a lot less drawer space. For smaller prints like this, a label maker works better than trying to 3D print the text.

More Dust Collection Adapters

Woodworking Dust Collection Rule 1: No two dust collection ports are ever the same size… EVER

Once again I find myself trying to fit a dust collection hose on to some of my tools and wind up having to 3D print a custom solution. Why is it always like this? This time it is a port for my random orbit sander to 1.25″ hose (which isn’t really 1.25″), one for my belt sander, and an adapter to go from that hose to my dust deputy inlet (which has some funky taper on it). The good news is that the ridges left over from 3D printing these always helps the adapter stay in place, even if it isn’t perfect. This is exactly why industry standards and groups like ASME and SAE exist.

Socket Cabinet

Not long after buying my first house I picked up a big set of socket wrenches from craftsman. Previously I had an odd assortment of hand me downs that were missing various sockets. The plastic trays the sockets came in were labeled and worked well. The case was always kind of shoddy. It tended to drop the drawers out and spill sockets everywhere. If you pulled the bottom drawer out the top drawers collapsed. I am finally ditching it and making my own cabinet.

I started by making plywood drawers for each plastic tray (1/4″, 3/8″, and 1/2″ socket set), and two more full drawers for extras. This is the first project I have done where I made the drawers all first, then built a cabinet to hold them all. Kind of a neat way to work.

Once I got all the drawers assembled and installed into the cabinet I covered the face frame of the cabinet with 1/4″ poplar. I thinned more poplar down to 5/8″ and put a heavy chamfer on it to make drawer fronts. I thought pocket hole screws would be a great way to attach the fronts. They were, but I forgot to reset the depth of the drill bit to 1/2″ instead of my standard 3/4″, and drove the first screw through the drawer front. oops…

That won’t matter too much, and I am sure nobody will notice. Mostly because I accidentally drilled the first set of drawer pull holes at 3″ instead of 5″. Otherwise the cabinet looks great after a coat of boiled linseed oil.

Now to fill it all up. I used small strips of plywood to make stops so the plastic organizer trays sit still and don’t slide left to right when opening and closing the drawers.

Everything fits with room to accommodate future purchases. I don’t do a lot of mechanic work, so this set will probably cover me for the very far future. Lastly I did 3d print a few little organizers and helpers. I seem to have a lot of 3/8″ extensions, so I made a little slot holder for them. Also adapters to go from 1/4″ hex drive to various socket set sizes. The steady drum beat of garage organization marches on.

Miter Saw Dust Collection

Miter saws are incredibly useful and one of the first power tools I bought that wasn’t a hand tool. As useful as they are, they produce a lot of bad dust. The high speed cutter makes a fine dust that gets kicked back and up out of the tool. The little catch bag that comes with them helps, but much of the dust still escapes and becomes airborne.

I tried attaching a vacuum to the dust port in the back, but that only catches about half the dust. The rest just blows right by. Instead a big funnel would guide all the high speed dust into a vacuum port. That was the thought at least. It works a little better than just using the saw’s dust port, but not much better.

I had some plywood rings left over from my dust collector upgrade and thought this one would make a nice base to start with. I attached a 2×4 with holes in it for dowels to elevate the dust catch.

The big gulp dust catcher attaches to a similar piece of 2×4 with some plywood in between to help spread out the load. The upper 2×4 had the holes reamed out so it would slide easily. A set of screws goes through the 2×4 into the dowels to keep everything at the right height. I didn’t know exactly what height would be ideal, so I made it adjustable.

To adapt from the big 4″ port to my mobile shop vac I printed some adapters with a 3″ PVC elbow. Once again, 3D printer to the rescue when it comes to adapting dust collection fittings.

I am still getting a lot of dust blown all over the place, even with this large catch. Using a large dust collector instead of my shop vac might help, but I feel like dust is deflected in too many directions by the time it gets to this big gulp. I have used this for a few weeks and haven’t come up with a good solution yet. It may require a better catch on the pivoting saw bracket. I will include any updates made.

Early 2019 Prints

I used to track my random prints closely and publish a monthly update on them. More recently a lot of my printing has been integrating with dust collection upgrades and other organizing efforts in my shop, so there hasn’t been a dedicated post. This is all still very workshop focused as that is where I have been directing my time this new year. The shop is becoming a very magical place to work.

First up is a used blade storage box. A sharps container. I was brought up using traptezoidal utility blades. The two sided retractable blade is a standard and is widely available. I lose them a lot, so I have like 10 of them around. They are cheap, and all of them have cruddy blade because I am too lazy to grab a screwdriver to open them up and flip the blade. Enter a new contender, the snap blade.

I always thought of snap blade knives as cheap box cutters. I bought one to try out after some online recommendations, and have become increasingly impressed. I think they are sharper, can be extended longer, and if you need a new edge, you just snap a segment off and get back to cutting.

Both methods leave sharp rusty around, so I printed a small box that helps you break the blades off and keeps them trapped inside for safe storage. Inside, the entrance has a ramp so blades would have a really hard time rattling out. It is like a lobster or crab trap. The entrance slit is just big enough for the blades to slip in.

I designed it to accept the 18mm snap knife blades, standard utility knife blades, and single edge razor blades.

I made a few and tried colorizing the raised text. I started with a paint marker, but the text was small enough it was getting smeared. I moved on to an ink stamp, but the ink is too thin. It soaked into the print layers and ran everywhere. You need something thick like paint, but easy to apply to a whole surface like an ink stamp. They look ugly but work perfectly. Thingiverse Link


I really wanted to spring for a nice whiteboard for the shop. One that doesn’t have marker stains 6 months after you first get it. I did a little research and found an enamel coated board that looked good. Where to put it though? My new shop is big, but lacking in wall space. time to get creative.

The circuit breakers are in the right real estate. I need access to them, but only occasionally. I noticed the gear track above the panes and decided to take advantage of them. I did a few test prints and came up with a double hook that snaps in nicely. Those supported two strips of wood that the whiteboard mounts to. The whiteboard is very stable and can be removed quickly when I require circuit breaker access.


I picked up a dremel around Christmas and have been finding it really useful for small odd jobs. I ditched the organizers that came with it and have put everything into a clear organizer box. To keep the cut off blades separated, organized, and from getting broken I printed a simple wheel holder.


After working on the old and new house for months my driver bits were scattered to the winds. Over time I kind of piled them up in one place, but never managed to get them back into the right organizer box. Instead I decided to revamp the top drawer of the toolbox that holds all my drill press stuff to act as a driver bit organizer space. I printed blocks with well spaced round holes to hold the short bits, and longer trays to hold the various 2″ long bits.

I ended up making smaller versions of the holed blocks. I have a lot of #2 philips and #2 square drives, and only a small smattering of everything else. Now everything is really easy to access and find. I definitely don’t need to buy bits any time this century. Stash beyond life expectancy.

Dust Collector Upgrade

I picked up my current harbor freight dust collector probably some time in 2010. For the price it is an awesome deal, but after these years it is time for an upgrade. The motor (lower left in left picture) pulls in dust and blows it into the upright section. Everything swirls around so big dust falls to the clear bag while finer dust gets filtered in the white upper section.

It is an ok principle, but has issues. The upper bag filters down to 5 micron, but no further. A very fine dust will land on everything in the shop when using this for a while. Those finer particles are bad for your lungs. The bag is a pain in the butt to replace and often gets rips in it from sucked up chunks of wood.

I spent about $350 on this upgrade. Over half of that was the filter. Considering a new harbor freight dust collector can be had for about $180, that is ludicrous. A new tool with good filtering and easier disposal is in the $1,500 neighborhood. We have had a ton of house expenses, so maybe a diy upgrade isn’t so ludicrous after all. I want to keep my lungs clear, so let’s get started. With a dust mask on, I ground off some rust spots and repainted with whatever green I had lying around.

I had thought about doing a lesser version of this many years ago, but never got around to it. I spent a lot of time thinking about how to do one upgrade and make it count. I will show where we are going, then explain the journey in steps.

The motor has been turned sideways from where it originally was. Below it is a pre-separator (red). It pulls out most of the junk before it gets to the filter area. As everything swirls in the upright the leftovers fall into my new bag replacement (blue), and finally out through a new hepa filter (green). Everything gets attached to a mobile base. Let’s start there.


Dropping Some Base

I was going to need more space for the pre-separator and wanted nicer casters than the original assembly, so I started with a cut bit of 3/4″ plywood. A set of 2×4 uprights with plywood and angle brackets support the motor in its new configuration.

The motor is really heavy and caused the base to flex a lot. I added a rib along the right side and eventually a 2×4 underneath to further stiffen the bottom. With that I had a good mobile base for my new dust collector.

I reused the circulator and upright rods to attach that section to the base.


Pre-Separator

Before hitting the motor or clogging up the filter most dust will be caught in the pre-separator. The design is called a Thien Baffle. The exact dimensions seem to be debated, so I just made it up as I went along. Basically everything comes in through a right angle port so it swirls around and gets flung to the edges. Gravity takes over for the particles and the air goes up through the center.

My circle cutting jig came back in full force with a lot of inside and outside cuts. I love this thing! I cut out a top for the separator and added a groove for the weather seal that would go up against the trash can top (left). Next I cut the baffle that keeps dust in the bin from getting pulled back up (right).

I clamped the two together and match drilled the 1/4″ threaded rods that hold the two sections together. I used the circle jig to drill out the 4″ inlet and 5″ exhaust ports. The inlet port is sized to allow a 4″ right angle dust fitting to slip into the top. The bottom goes onto a 4″ tight PVC drain elbow. I custom printed this to work with the parts I had around. I used silicone calking to seal it and screws to hold it in place. The center is larger and will accept 5″ hose to go between the separator and motor. Same method of silicone calking and screws to seal and hold.

I bolted the bottom baffle on and fitted it all to the metal trash can. This section is before the motor, so it will be under vacuum. I think the metal can will do better than a plastic one in preventing collapse.

I added weather stripping to the lid where it interacts with the trash can overlapping the interface to help form a better seal. With everything underneath I just needed a short segment of 5″ hose to attach the two.

Here is the pre-separator fully assembled and in place.


Bag Replacement

Ideally, most of the dust is already out by the time it passes the motor. Some will still exist and it will need a place to go. Instead of a thin plastic bag that rips and is difficult to install, I wanted another rigid bin. A 20 gallon rubbermade can was just about the right size. I temporary attached two pieces of 3/4″ plywood and match cut the interior and exterior diameters, the cutouts for clearing the metal upright bars, and holes for screwing the two halves together.

The upper section had a groove in it to lay a generous bead of silicone calking to help it seal with the metal ring of the circulator. It turns out that ring isn’t very circular, so the gap in that groove varies wildly.

I didn’t trust the calking alone, so I cut down some right angle brackets and drilled/screwed them into place to help support this mating ring.

The bottom half of the mating ring will attach to the 20 gallon trash can. I installed 1/4-20 T-nuts so a bolt can come in from the top to draw the can up and seal it. I put another thick bead of silicon calking on the ring and screwed the can down through the lip. The combo of screws and silicon made for another slid connection.

It is pretty important that you don’t let this section get too full. Otherwise the circulation of dust might get up to the filter and damage it. I cut a thin section of clear plastic and added a viewing port to the can.


Last but not least is the filter. Made in America from Wynn Environmental, the filter is a majority of the cost of the project. The new filter gets down to 0.3 micron instead of 5 micron. That doesn’t hamper flow though, instead of the 30-something square feet of filter the bag had, this one has over 200. The kit comes with little cleats that look like modified hose clamps to strap everything down from the inside.

To test out my new vacuum rig I had 20 board feet of 4/4 maple to plane. I got through all the boards and looked into the grey plastic bin. I was horrified to see a pile of shavings in it. I thought the pre-separator had failed to… well separate.

Turns out the pre-separator was past full and the shavings had gotten up past the baffle into the final stage. Good thing emptying both sections is easy and only takes a minute. The newly revamped dust collection rig works well and the pleated filter on top makes it breathe even better than before the pre-separator was added. Very happy with this upgrade.