Tormach Power Drawbar piston service

For some time my compressor has been intermittently kicking in without anything running to justify it. By chance I heard a slight hiss and then felt a small ‘breeze’ coming from the bottom of the Tormach drawbar compression cylinder stack. This device has three pistons stacked together to give enough downward pressure to open the drawbar gripping the TTS collet. The machine was installed in 2016 so the seals have done quite well to survive this long.

I did some web based research and found that Tormach offer a seal replacement kit so clearly this was something that was an expected service activity. I ordered the kit (which cost less than the courier charge). Here is an image of the kit.

My research also found a very old YouTube post by John Saunders at NYC CNC where he describes how to undertake the service activity. It looked like a job I could manage.

My PCNC440 model was slightly different to John’s in so far as removing the piston assembly out of the machine. On mine you have to just remove a single shoulder bolt and a pull out pin. However before doing this you need to put any of your TTS tools in the collet to relieve the pressure from the cylinder plunger head. Once this is done, turn off and bleed the air supply before removing the two air feeds. Mark them so you know which one goes to which port. Also mark the three piston sections with a Sharpie so you know which order and orientation they are in.

The piston stack has the three sections clamped together with four bolts inserted from the top of the stack. The bottom end mounting plate also has long screws that pass through spacer tubes but only fasten into the bottom piston section. Note that these spacer tubes might well have some large additional height setting washers so don’t lose them.

I suggest removing the bottom three screws first of all so you are left with just the three cylinders still held together by the top four bolts.

Now for a tricky part – you need to remove the large circlips that are fitted to the top and bottom ends of the piston stack. These are not easy to remove unless you have a decent tool to grip them. Basic handheld circlip pliers are unlikely to perform and you could end up search the workshop for flying circlips. For this reason you must wear some eye protection while removing the circlips. I bought in a pair of these pliers and they were superb for the job.

Once the circlips are removed you can remove the four top bolts holding the stack together and be able to split the three sections. Be careful how you do this so you see and understand what is where and the order of assembly.

The end plates that were held by the circlips are pushed outwards. All the other sections should freely slide out as appropriate.

With everything ready, start from one end of the assembly and do a logical swap out of the old seal and swap in the new one and re-assemble that section. Clean off any debris in the seal grooves and add new grease to the seals and their locating grooves. I used silicon grease.

The kit comes with 6 standard section O rings, 3 wider section rings and 3 central piston seals as shown in the image above. By swapping only one seal in and out at any one time you get a good control check that you haven’t missed anything.

My kit also had some small O rings that are not shown in the Tormach image of the kit contents. I can only assume that the kit is universal to a number of other piston types.

Update : Tormach has since confirmed that the extra small O rings are for the 770 and 1100 versions only.

The whole swap out activity took around 2 hours. This piston worked fine when re-installed back on the 440. “Phew!”

Eccentric Engineering Turnado arrives

Another asset to the workshop tooling register

I love to use gravers. It is like turning wood but with metal.

I have four regular use gravers made to William Smith’s receipe, two for general turning, two for parting. These get used in conjunction with my Hemminway quick release hand turning rest as shown below.

There is something very therapeutic about being in direct contact with the material being worked on rather than being decoupled through a tool post and handwheels.

I have a potential project looming that will require hand turning and on a larger scale than is practical with my gravers. If I had a CNC lathe this would be straightforward but alas this is something maybe for the future. After some research I came across the Eccentric Engineering Turnado hand turning device. There are a few videos on YouTube about it and I believe Quinn at Blondie Hacks uses one. She also uses Eccentric Engineering’s tangential/diamond toolpost which is another of Gary’s useful products. Here is a screenshot from Gary’s site.

I took the plunge and ordered a Turnado. It arrived on my doorstep here in the UK 3 days after posting from Australia which was impressive.

The kit as received needs dedicating to the lathe on which it will be used. This involves deciding how to mount the working table on the carriage and setting the lathe centre height correctly. Setting the table height involves turning down five pillars to the correct length – quite a simple process you would think…. but I blew it and cut them too short. Totally inexcusable clang and I had to remake them. Very red face and very blue language resulted. The correct gap between the two plates was 12.7mm on my Myford.

The mounting on the Myford carriage needs a round boss that matches the boss under the standard top slide assembly. I measured this as best I could, modelled it in Fusion and 3D printed a prototype.

The 3D model worked fine. With confidence restored in my ability to measure properly I turned up the boss in steel. All went well and the Turnado table mounted correctly and gripped very well on the lathe carriage. Here is a picture of the lower side of my finished assembly. Apologises for the pink 3D model – of late I have had a heavy demand from grandchildren for Barbie related models.

Having now played with the Turnado I can say that it is a lovely well thought out piece of engineering and works well. Using the hand tool is a delight and the accessories for profile turning will be indispensable.

Nice product Gary.

Links to similar or related post are listed below : –

Workshop Diesel Heater Update

Some answers to questions from readers

My blog post about installing a Chinese RV diesel heater in my workshop is probably the most popular post visited on my blog. This has been even more so with the present cost of fuel and the onset of winter weather. You can read my original post here and I suggest you read that post first of all to make more sense of what follows.

First let me say that installing the heater was one of the best workshop improvements I ever made. The heater performs very well and quickly gets my working area up to temperature. My opinion needs a bit more defining.

My workshop is contained in what should be the house garage and is roughly 6m x 4m x 2.5m. It is built onto the side of the house and has one outside wall which is an unfilled standard brick cavity. I have covered the garage door with 1″ Cellotex equivalent foam boarding. This was convenient to mount to match the door construction and probably the thickest I could use without impacting on the garage door operation. My wife has provided a door bottom ‘sausage’ muffler filled with polystyrene beads. The door is therefore relatively draft proof but not perfect.

The roof over the workshop is double skin plasterboard and has timber joists with 6″ of fibre wool insulation.

With the current overnight temperatures (-4C) the temperature in the workshop drops to around 15C. The heater is a 5kW branded model but likely to be only 3kW in practice. It takes around 1 hour to get the temperature up to 19 to 20C in the present externally very cold conditions.

Fuel – I use an approximate mix of domestic heating oil (40%) and vehicle diesel (60%). Why do I do this apart from cost saving ? I have read that domestic heating oil does not have sufficient lubrication content to lubricate the demand pump action in the heater. I therefore err on the conservative side and use a mix of the two. I have no idea whether this is fact or fiction. I do not have access to red (Agri) diesel so this is not an option for me to use but clearly would be the cheapest route and would provide the necessary pump lubrication.

I have a 20 litre diesel storage can which I fill at the local garage every 2 or 3 weeks. This is eyeball mix tipped into the heater internal 5 litre tank together with the heating oil which I siphon out of our domestic tank as needed. I would estimate that I use 5 litres of the mix every 3 to 4 days depending on outside temperatures and based on at least an 8 hour day ‘making things to make things’ as my wife calls it. If the heater tank runs dry I find I do not have to re-prime the heater pump but simply refill the tank and switch back on.

The heater controller is the second one I have fitted. The display died on the first one. The controller is easy to use and allows timed operation, set temperatures and live temperature readouts. It is a three wire connection and I had to extend the cable length with a spliced in 3 core section. The OK button cycles round the various display readings and the ON/OFF symbolled button is the lower middle button. The heater needs a single very short press to start the heater up and a longer press to shut it down. Over pressing the ‘start’ leads to an abortive shut down procedure. The left and right arrows increment the various settings selected by the OK button.

The start up current is very high, around 10A at 12V. The choice of power supply is therefore important to be able to sustain this surge. The controller display allows the value of the supply voltage to be checked. The heater once started roars away at full pump speed (a very fast clacking noise) and once at the temperature set point the clicking drops down to a slow tick. There is an icon on the display that mimics the tick. The sound from the ticking is conducted into the workshop via the inlet and outlet air ducts. Like the ticking of a clock, you just get used to it and mentally cancel it out. Both the roaring at switch on and the ticking are louder outside the workshop than inside but these do abate once the heater reaches the set temperature. I am conscious that both the roar and the tick are probably audible with the neighbours but their ground source heat pump is equally audible to us.

The shut down procedure after the long press on the controller button initiates a full bore roar from the heater. I assume this is to burn off accumulated soot in the heater from the slow background tick reached at temperature set point.

As mentioned above the exhaust is noisy. I believe that the choice of silencer affects this. Straight through ones are to be avoided. There is also some discussion about having two in series to reduce the noise further. I have not tried this. Note also that the exhaust does create black soot so I have fitted an aluminium sheet on the wall to protect the brickwork. Standard shower cleaner spray with a bleach content does remove this. The soot plate can be seen in the image below along with the 20 litre top up container.

My prior post about how I installed the heater details the inlet and outlet duct locations. The heat outlet grill is on the workshop wall between my two milling machines. This is not ideal but was the only practical location. The return is under the Myford stand.

The heat outlet has the shortest duct run being almost directly at right angles through the wall from the heater burner outlet. The return duct is located under my Myford lathe stand and is a simply constructed wide mouth housing tapering down to the flexible duct that connects back to the well insulated ducting along the outside wall to the heater. I have fitted a fine gauze mesh over the mouth of the taper to stop debris entering the heater. The image below gives some idea of the construction to fit the available gap under the Myford.

I think I have covered most of the questions asked by readers but feel free to contact me if you need to know anything further. Clearly everyone’s setup is different but for my workshop this is an outstanding and relatively low cost comfort benefit. It also creates dry recirculating air that benefits my equipment.

Links to similar or related post are listed below : –

Qidi I-Fast arrives and I am impressed

Decision made on the new 3D printer but it’s big

As per the previous post I have been debating long and hard about which new 3D printer to buy. Strangely enough my wife gave me a hard time about my indecision and told me to just to get on with it.

Qidi sell into the UK market via Amazon and having placed an order, a very large box arrived very quickly onto the doorstep. Very large. But also very well packaged with very good unpacking instructions. It did take the two of us to lift it into position on the bench. Which was the second problem – where to put it. The temporary position is on the side of my desk but this might change.

qidi i-fast printer squeezed onto my desk

The I-Fast has a dual extruder and you get both a high and a low temperature extruder head which are easily swapped out depending on the filament being used. Print size is huge being close to a 300mm (1 foot) cubic space. Two filament dry boxes are provided to keep moisture out of the filament (although I haven’t used these yet). Qidi provide a print slicer which looks a lot like Cura and so far seems fine to use. There was no problem in linking the export from Fusion 360 directly to the I-Fast.

I’ve run some test prints and find it fast and very quiet compared with my old Sindoh DP200 (which is currently sat sulking in the corner). More to follow as I get used to it.

Links to similar or related post are listed below : –

November update

Mainly jobs in France and 3D printer choice plus thin wall printing

Sorry it has been quiet on my blog. We took a few weeks off in France. This should have been relaxing but things got in the way. Our elderly French neighbours seem to store up their ‘can you just have a look at’ jobs for when we arrive. This ranged from leaking coffee percolator, dead washing machine, DVD player not working etc. I don’t mind this because in return they keep on eye on the house for us. The only frustration is that I am not as well kitted out with repairing resources as I am here in the UK.

From our point of view the spa was coming up with two error messages – no flow and UV lamp needing changing. The flow problem was traced to the flow sensor. This I think might be a Hall Effect sensor that is tripped by a magnet on a thin metal strip that is bent towards the HED with the water flow. It could equally and more likely be as simple as a reed relay that is tripped by the magnet. I managed to source a replacement from a French source.

The UV lamp was not so straightforward to replace but I did question the validity of the message on the display. The UV bulb has a recommended life of 2 years. The software in the spa has a clock which we reset to current time and date when we turn the spar on for each visit. The UV bulb life is based on the clock count down. I am not sure whether it is recording the period from clock time to clock time or the actual running hours given our intermittent short period visits. I carefully checked that the bulb was still glowing brightly and then reset the countdown timer. I’ll take out a new bulb next visit.

There were various other distractions but the weather was amazing for October with one or two days reaching 30 degrees.

Arriving home I have landed a project that requires 3D printing items that need a Z height of over 200mm. The project also needs thin wall printing. My trusty but now dated Sindoh DP200 falls short on this. The Sindoh has been a loyal and reliable device giving me few problems and repeatable quality print results. The main frustration has been having to be single sourced on Sindoh PLA or ABS as their filament has to have the associated custom Sindoh personality chip. Later versions of the Sindoh range (1X and 2X) purport to allow third party filaments to be used.

This has led to some soul searching. I am now comfortable with the concepts involved with 3D printing and have felt for some time that an upgrade of printer was on the cards. My wish list clearly needed to include allowing 3rd party filaments and not just PLA and ABS. (Carbon fibre being very attractive). The list also included an increased build volume and possibly a dual nozzle.

Clough42 has had some recent videos focussed on the Qidi products, namely the I Fast and the X-CF. Qidi also have the X Max. All three of these printers have Z heights of 300mm. Pricing is not low but these are all enclosed printers. There are many other Qidi review videos on YouTube. Qidi seem to be hot on support which is good news. So I have a debate raging on whether to jump and which way. Here is my basic spreadsheet comparison chart which includes the Sindoh 2X as a possible contender. Sindoh might be moving away from their own models and working with more higher end products under their brand Fabweaver. There are some interesting technology articles on the Fabweaver blog.

I investigated the thin wall printing issue and came across a very interesting post by Wayne from SoarKraft. Wayne uses thin wall printing on his slope soaring glider models and he details how Cura and Prusa slicers (free downloads) have only relatively recently caught up on this whereas Simplify 3D (subscription) has had it as a facility for sometime. Wayne’s video is worth a watch. The Qidi printers like many other manufacturers use a variant of Cura. There is a very good support article on the Simplify 3D site that relates to thin wall printing.

My printer upgrade debate continues but the I Fast looks the most attractive. The only problem is it has a large physical envelope and I don’t have a plan where am I going to put it in the office/workshop……

Links to similar or related post are listed below : –

Verified by ExactMetrics