Woody – Page 9 – Woody's Workshop

September 28, 2023September 28, 2023

Fitting a Bento air filter to a Qidi ifast 3D printer

Hopefully less tickly throat and itchy eyes?

For some time I have been subjectively conscious of fumes created by my 3D printers. There has been quite a lot of general comment about this problem in the technical press. I mostly use PLA for my prints using my Qidi ifast and Sindoh 3DWOX. If you believe the press, PLA is the least likely to cause irritation. However, my office is small and the printers are both close to my desk so any fumes are likely to be immediately adjacent to my computer activity. If I do a long print run, I can sense the fumes as a background smell and as an irritation to my throat.

The geography of my office and workshop are such that moving the printers is not an option nor is finding some way to vent to the outside world. The Qidi ifast is a huge machine and finding a new home for it would be difficult. Transferring both machines into the workshop would expose them to a residual albeit low level of moisture (nothing rusts in the workshop so it can’t be so bad).

I came across the Bento filter unit which is a free download from Printables. As an aside Voxel in the US sell Bento kits.

The concept of the design is to house a complete filter unit inside the printer chamber where it acts as a recirculating air filter (a ‘scrubber’). This only acts on the air circulating within the chamber. This should avoid creating cooling drafts across the print job which might be the case if high volumes of air were being ventilated in and out externally.

The unit is visually shown opposite. It has four sections all stacked one on top of the other. The air in the printer chamber enters the top section which contains a commercially available HEPA filter cartridge. The next section is a carbon filter. This has an inner printed magazine containing carbon pellets. The fan section is next with two fans pulling the air through the two filter sections. The bottom section is the air exhaust duct. The design is rather well conceived with each of the two filter sections clipped together using small magnets. This makes these two sections easily demountable for filter maintenance. The fan tray and exhaust duct are held together with screws and brass inserts that pick up on the fan mounting holes.

Circulating the air into the unit via the top section and exhausting at the bottom is a nice idea. In the Qidi ifast the print head stays at a constant height and the print bed moves down as the print builds. The print head activity remains at a constant height to the filter input. There is a lot of web discussion on fitting the Bento to Bambu Labs units but little about use in other printers so some head scratching was needed on how I might implement the Qidi ifast installation..

Here is a link to ZIP file containing my write up of how I installed the filter in my Qidi ifast together with the STL files for the modified fan tray, exhaust duct and microswitch mounting block.

qidi-ifast-filter Download

Links to similar or related post are listed below : –

September 21, 2023September 21, 2023

Soldering Iron bit storage on Lytool soldering station

Including a 3D insert tip holder

In my recent post on a 3D print insert stand I mentioned the use of the Lytool soldering iron station. This uses a Type 936 style soldering pencil and it is supplied with five different profile soldering tips. When using the iron for non insert related soldering, I have found it lightweight to use, very quick to get to temperature and generally a good alternative to my Weller TCP1.

After some research I found that the best match 3D inserts tips for the Type 936 pencil are a screw in set with a common mounting bit. Here is the Amazon link.

Having now got five different soldering tips, the insert holder and six 3D insert tips, things were getting a bit messy and a potential recipe for something getting lost with all the ensuing frustration. The solution was a simple holder for these various components that mounted on the Lytool soldering iron holder. Here is the Fusion image.

and here is the finished item mounted on the soldering iron holder.

Clearly as a 3D print you can’t go putting a hot tip on a plastic prong … but that aside it is functional. As an alternative you could replace the prongs with M4 screws. Here is a view of such a variant. This uses M4 x 15mm countersink screws but space is restricted on the rear side to allow for the screw head size. There is still room for seven standard tips. If the threads don’t print well then the screws could be fastened with nuts on the top side instead. This would also protect the body plastic from any residual heat in the tip.

Here is a ZIP file with the STL files for the two versions.

soldering tip racks Download

Links to similar or related post are listed below : –

September 4, 2023September 11, 2023

Tangential Lathe Toolholder for Myford Super 7

Yet another design to add to the plethora out there

The concept of a tangential lathe tool holder had passed me by until Blondie Hacks mentioned it in one of her YouTube posts. This resulted in an hour or more lost down an internet rabbit hole. The conclusion seemed to be that I was very late to the party. There are many designs out there which include the Eccentric Engineering commercial item.

I quite liked the look and simplicity of Mike Cox’s design. With the knowledge gained from my unintended meandering internet research, I tweaked it slightly and committed it to Fusion 360. This is shown in the pretty picture below. Note my design was to be mounted in a QCTP on my Myford Super 7 and is intended to hold a 3/16” HSS tool. Here is my Fusion 360 image of the model.

The following ZIP file contains my full write up along with the Fusion 360 model for the toolholder and an associated 3D printed sharpening jig.

Update : This tool is very good. It can tolerate decent depths of cut and leaves a nice finish both turning and facing.

tangential-tool Download

Links to similar or related post are listed below : –

August 22, 2023September 6, 2023

Hemmingway Sensitive Knurling Tool

A rite of passage ?

You may have watched James at Clough42 and Brandon at Inheritance Machining both make the Hemmingway Sensitive Knurling Tool (HK# 1115) and shared their experiences. In the past I have made a few Hemmingway kits and always enjoyed making them and the associated learning process. I decided to add the knurling tool to my collection.

Like James and Brandon I found the drawings beautifully presented but a little dyslexic with imperial dimensions showing as a mix of fractional and decimal units accompanied by metric equivalents. To get more intimate with the design and to circumvent the fraction and decimal imperial dimension issue I resorted to redrawing the design in Fusion 360. Fusion lets you set an overall dimension standard for a drawing but you can enter an individual dimension in any format or standard. Fusion will then display the individual dimension at the default drawing standard. This allows you to enter any dimension in mm, fractional Imperial or decimal Imperial. I find this a convenient way to better interpret the Hemmingway drawings. Redrawing in Fusion also highlights the potential problems in the rounding of metric dimensions from the imperial entries.

James and Brandon both resorted to traditional methods for the construction. This involved using a rotary table for the curves (of which there are many on the two jaws). I will now add further to my reputation of being a lazy engineer. Having redrawn the design in Fusion it was a logical step to produce the kit with CNC assistance.

While CNC might make the construction appear easier, it still creates headaches on work holding. This is magnified by the fact that the kit is supplied with ‘final size’ material. Brandon took this further by skimming all the supplied stock but then fell foul of the subsequent impact of this on some parts.

The CNC machining of the side plates, jaws, adjuster plates, spacer block and mounting block all went well to my CAM processes. This required sacrificial mounting plates and lots of checking before hitting ‘GO’. I am pleased and relieved to report no dings resulted from the CAM.

The majority of the remaining parts are lathe activities with, where needed, a liberal use of a collet block for cross drilling . I cheated on the adjuster thread and used M8 threaded rod with appropriate dimension changes to its mating components.

I had one post CNC ding on the lower jaw leading to an additional M3 hole. The lower jaw nut was the most probably the most tricky part. That aside all went to plan.

I used the semi finished tool to knurl the adjuster knob and pressure lever knob and was very pleased with the clean knurls that resulted. Here is my finished knurling kit mounted on a Myford QCTP holder.

Would I recommend the kit ? Yes – but it has some slightly advanced activity needing careful planning and thinking. The drawing dimensioning can catch you out. I think redrawing in Fusion helped highlight and clarify these issues. Measure twice and cut once is the order of the day particularly with respect to shaping the jaws. If you have CNC then this is a much easier way to go once you have got your head round the necessary work holding.

Note – the kit does not contain the knurling wheels so you need to order them separately.

Overall this has been an interesting and challenging project. I now have a very useful asset added to my workshop tooling.

Links to similar or related post are listed below : –

August 13, 2023August 14, 2023

Automated 3D printed collet storage using Fusion 360 parameters

How sad is this ?

I recently bought an Imperial set of ER25 collets to compliment my metric versions. I also have a set of metric ER20 and ER11. They have all been delivered in little yellow boxes which is good from a shipping point of view but a faff when needing to use them. In the past I have made storage blocks using odd pieces of wood with tapered holes cut using a cone cut drill bit. The cone cut has a 6 degree taper and ER collets all have 8 degrees so it sort of works but not quite ideal for my perfectionist mind.

As ever, the 3D printer sits in the corner begging to be used and Fusion 360 challenges me to do something a bit more professional. The scene is set for an overengineered collet storage tray.

Now I could just model and print something to hold the twelve new Imperial size delivery but what if I add to them at a later date? What if I decide to get some ER20 Imperial versions also ? ……….. Could I create a Fusion based automated model that will cope with any sized matrix of holes and any size of collet?

The first exploratory step was to create an Excel spreadsheet (another of my fascinations) as a means of identifying the steps that might be involved in automating the design and to tabulate the different parameters of the various ER series collets. Here is a screen shot.

A little bit more detail will be needed for you to understand what this all means.

The top table just details the published specification dimensions of the ER range of collets. I needed the height of the tapered section and this is calculated. Note that not all collets have the parallel section at the top of the taper. If you extrapolate the taper it then coincides with the dimension D1 and this is one I have used in the calculations.

Each collet holder hole in the block will be an 8 degree tapered hole that the collet sits in such that it does not sit all the way through the block (I opted for a 1mm bottom gap) and such that a percentage of its height protrudes from the top of the hole (I opted for 30%). The middle right hand sketch shows the various parameters and the red outline represents the collet.

The lower table shows the set up for the model parameters with spacing and borders defined. This section allows entry of the all important ‘how many holes do I want’ and the aspect ratio of the matrix. The final two red lines shows how big the resulting storage block will be.

All with it so far ? This is so embarrassingly sad … should I even be thinking of posting it…

These various parameters are now mirrored and entered in Fusion 360’s Fx parameter set up. I have tried to be logical in the naming convention and the blue stars indicate a function that is defined and entered by the user and will also appear in parallel in the Fx Favourites listing. This allows a focussed entry of just the variable parameters without all the other background calculation clutter.

I wanted to round the resulting block size to a nearest whole number. My preferred function in Excel is “mRound” where you can define the rounding to an increment value. There is no such equivalent in Fusion. In the end I used the “Ceil” in Fusion and “Ceiling” in Excel but Excel’s “Ceiling” requires a ’rounding to value’ hence the entry line (R) in the Excel listing which is set to ‘1’ to make it match the Fusion calculations.

By setting the length and width hole count to ‘1’ a single holder can be printed and checked to dimension before doing a full matrix as needed. I found that on my first single hole print the collet sat slightly higher in the hole than designed but this was traced to a print artefact on the taper wall. This was was easily rubbed down. On similar tack, I have allowed a fudge factor for print shrinkage should this be needed. Any errors in this respect will cause the collet to sit higher on the block. This will be most apparent as the collet size reduces. The value entered (say 0.1mm) adds a linear amount to the top and bottom hole sizes and therefore the taper.

Once you are happy with the single hole print you can define the number and aspect ratio of how you want the holes to be printed on the finished block. A 6 x 2 print will match the normal 12 piece ER25 collet set. On the Qidi ifast printer this took around 4 hours at 0.25mm layer height. Note that I used the ‘Shell’ command on the block lower surface of the print to reduce material use. This means you need to place on the printer bed ‘bottom side up’.

Well I did say this was going to be a sad nerdy post but as ever I learned a bit more about Fusion, Excel, refreshed my school geometry and made the workshop even more tidy and organised. What’s not to like ? …..

While this is an almost facetious waste of time and effort, the principles used in the Fx programming has many other applications.

The planning spreadsheet has been added to my spreadsheet compendium which along with the Fusion file (for ER25) is attached on the following ZIP file link.

My Engineering Spreadsheets plus Fusion ER series Download

Links to similar or related post are listed below : –