Swiveling Dust Collection Fitting

My dust deputy cart is doing a reasonably good job of helping me keep clean. One place that falls short is the hose that attaches to the inlet of the dust cyclone. The inlet part is tapered and the plastic is quite slick. A picture from my original post shows that I originally held it in place with zip ties. I moved on to a hose clamp, but that didn’t work either. It always gets twisted up during use, and it falls off constantly. I need a connection that can swivel and stay attached.

My solution to this issue is to 3D print a tapered ring with threads (red below). A loose tube butts up against that (yellow), and is held down by a nut (green). I did a cross cut shot to show what it looks like when assembled (lower right). My CAD software introduced a few new colors to confuse the issue.

I had a lot of blue filament lying around so I made everything out of that. The tapered base goes on and screws into place to keep it from falling off. I then screwed on the big nut to capture the 2″ hose adapter. The nut threads interfere heavily, so it won’t move without a lot of effort.

I tightened the nut down enough to form a reasonable seal, but loose enough to let it swivel. To connect the hose to the swivel section I again used a hose clamp. This time I printed and glued on a little handle so you don’t need a tool to loosen or tighten the clamp. Ask me in 3 months if I like it or not.

Rolling Sink Carts

Now that my summer slog rock project is done, things have cooled down enough to get back into the shop. I am still refining the organization of my shop and turned my attention to the area around my sink. There was a pile of spray bottles and gallon jugs of cleaners scattered all over the place. I wanted to make a little set of carts that slide out to hold the junk.

The two carts sit low on either side of the sink and roll out to expose all their contents. These are already mostly full which means I either made them too small or I need to pair down the stuff I keep around.


I designed this project back in the spring based on a gallon jug of headlight fluid and two scraps of plywood I had. Thankfully 6 months later the jug was still the same size and the plywood was still there. The design is like a two shelf book case, only with no back. I made runners to go on either side of the shelf to prevent sag and keep everything from racking.

The assembly was mostly glue and brad nails, and once dry felt quite stiff. I gave everything a single heavy coat of polyurethane. I would typically use boiled linseed oil for shop furniture, but had some old urethane around and figured these would get splashed around the sink quite often.

I found really small wheels to put on the bottom. They don’t swivel, but I don’t need them to. The carts just roll in and out. Plus their compact size means I waste as little space as possible. Lastly I printed a beefy handle on top to help me grab and roll the loaded carts.

Sprinkler Tools

I have been doing a lot of trenching and digging in my yard in service of a rock border project that has been going on for months now. One result of that project has been a lot of sprinkler repair. I have broken pipes underground while cutting up roots, and tried to dig straight through hidden sprinklers. That plus regular sprinkler maintenance has been a new chore for me. The last house didn’t have them and I am learning on the fly what I have and how to fix it.

Most of this is pretty routine plumbing, but repairing or replacing sprinkler heads is a bit different. They are buried, and often very overgrown with grass. Once you get to them, they tend to be tough to pull out of the ground. To help with all this I 3D printed some tools.

First up is a large hole saw looking device. A 1/4-20 bolt fits in the center and gets chucked up in a drill. It has a 3in ID which encompasses all my sprinkler heads. I had a sprinkler that needed to get an extension put on it, so I used it as an example. The bit breaks up the soil and grass around the sprinkler head making it easier to fully expose and extract.

Even with the grass broken up it is still hard to get a hold on those sprinklers without doing a lot of digging. To help with that I made a tool that grabs onto the ribs around the head and provides a good handle. It made extracting the unit very easy.

That one is designed for a Toro 570 series sprayer. I also have some Hunter PGP sprinklers that rotate on their own. Those are a lot bigger and require a different tool to extract. All the designs are bundled together on a single thingiverse post.

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.