This is an update on the progress that Tyler Reeves is making in further reducing the size and weight of his home-grown pad inflator. It isn’t available yet, and may differ substantially from the prototype shown here, but watch this space…
Three Points of the Compass has been content to bury an extra piece of gear in the pack for the past few years. Instead of relying on lungs or pump sack to inflate a sleeping pad, I have been including a little battery powered pump. At first it was the Tiny Pump from Flextailgear, but I always slightly resented the 88g weight penalty. Then I came across a ridiculously lightweight alternative and began using the Pad-Pal, devised by ultra-lightweight backpacker and innovator Tyler Reeves. Complete with an adapter for a Thermarest Winglock valve, that earlier v4 version weighs 10.6g. His latest prototype, including valve adapter, is tipping the scales at just 7.6g. However a little weight might have to be added back to answer the critique of this pared down prototype.
Tyler has made a first batch of twenty of his prototype v5 Pad-Pal, which were sent out for beta testing. Following feedback, and the necessary changes, his tweaked v5 may then start being produced. The cost has yet to be ascertained, but it won’t be cheap. More on that later.
Tyler was kind enough to recently send me his latest iteration, a prototype version of the v5 inflator, gratis, for assessment. You can see from the above image that this latest version turns the scales at just 7.6g, complete with an improved valve adapter. Ducts and valve adapters are 3D printed so there is a miniscule difference in weight between units. However it isn’t just the weight that Tyler has been working on. The design has been completely revised and it is now a great deal smaller, has a much improved motor, is more powerful, and now has additional features such as speed control and heat sink. But this inflator isn’t quite there yet.
Tyler developed a custom PCB that acts as both motor controller and power management system. This is a crucial, important and large part of the design. On such a small inflator, options for placement are limited. Attempts were made to split it into two and mount on the side of the fan duct but, so far, this has proved unsatisfactory. Not least because the extra wires and solder required are heavier than the prototype that utilises a dangling unit with added housing, even with added heatsink. The current dangling board is not particularly successful however and side mounting as a solution may have to be returned to.
Three Points of the Compass is not the greatest fan of the new method of mounting the control board. This is encapsulated inside a 3D printed case and clipped across the inlet of the fan duct for storage, then unclipped and left dangling on wires during operation, there is a USB-C connector in the end of this for attaching to the required powerbank. Most Beta testers agree that the unprotected thin wires attaching the PCB to the duct are an area of concern. This is easily remedied by adding shrink wrap.
The PCB itself is no longer exposed and has been given a little more protection from damp. An acrylic coating has been added to the circuitry to provide further protection. There is both a small heat sink added and a small button switch on the unit that can be used to cycle through the four power modes.
Once a powerbank is attached to the USB-C connector, the motor starts off on low power mode, a click of the button switches to mode two, about as powerful as the previous version of Pad-Pal, then mode three- twice as powerful, and finally mode four, about three times as powerful. It will inflate an Uberlite pad in around 40 seconds and a large NeoAir Xlite in less than a minute.
The much reduced-in-size duct now gives the impression of being weaker than previous versions, though this is not borne out by actual crush testing. Even if it cannot be easily crushed, it can be deformed and may require gentle bending to stop the blades from hitting the side walls. Though unlikely to occur, the chance of deformation occurring when tightly enclosed in a backpack is increased. While heat sink fins have now been incorporated into the PCB, it might be better if mounted across the duct so that passing air can whip away heat. Tyler did use this method on a few prototypes but currently thinks the control board too large to practically mount in this manner. If it could be mounted across the duct, this might add both protection to the fan and rigidity to the duct.
Heat shrink wrapping the control board might have been a solution to waterproofness and I have included an image showing one prototype that incorporated this method. However it was difficult (certainly at an automation perspective) to get the right fit and assemble sufficiently neatly. Beside that logistical headache, this is an expensive piece of kit to produce and a bit of shrink wrapping over the control board simply does not impart a quality feel. The largest problem with the Pad-Pal as a product is created by the 3D manufacturing materials and method. The finish gives an impression of a cheaply made and fragile object even if that is not the reality. This can affect peoples impression of value for money. Tyler has already been experiencing feedback from purchasers unfamiliar with the appearance of 3D printed products and querying if they are in receipt of manufacturing defect. He has to be careful to create a premium priced object that looks like a premium priced object.
This is a small volume, cottage industry. At cost, parts and shipping total some $28.50, of which about half is comprised of an off-the-shelf electronic speed control and custom made motor control board. This equates to a circa $60 sale price. Even with the improvements, especially greatly improved motor life, few will pay that, so a way has to be found to bring unit price down to a more acceptable $40-$50. This is partly solved by also using a custom electronic speed control.
The exposed rotating fan blade continues to be an issue. The more powerful motor has simply exacerbated the danger. Beside the chance of putting fingers in the way of the rotating blades, I have found that the extreme lightness of the inflator means that it can easily blow and twist around if running and not secured to a pad valve. This increases the risk to the fan blades inside the duct, that they might strike something such as a loose tent floor or side wall. This looks like an area where Tyler will have to add weight and an enclosed version might have to result. But would this really matter, particularly if it also strengthened the fan duct and prevented deformation of this area as a result? An extra gram could potentially be justified here.
A small batch of glass reinforced nylon ducts were printed for testing and proved more rigid. A more expensive option is carbon fibre reinforced polycarbonate. Whatever material is eventually used to make the ducts will not only have to be a practical and realistic solution but will also have to be a balancing act between material availability and cost, and what consumers will pay.
The earlier variants of the Pad-Pal had cheap and easily field replaceable motors. This is necessary with life-limited consumables. These are micro-motors built for drones and wear out after a certain number of hours operating. The fans last longer but once removed from a motor, can then be too loose to re-use and also require replacing. Despite having been offered a cheaper option, people were, and are still, expecting longer life from the motors, which means incorporating a significantly more expensive brushless motor in Pad-Pals moving forward. This is now the Happymodel SE0702 26000KV 1s Brushless Whoop motor. These are heavier, and, here’s the pay-off, better performing. These did also present the designer with the challenge of developing an electronic speed control (ESC) for a brushless motor.
The motor is mounted into the duct with three tiny screws and this and the fan remain interchangeable and user serviceable, but are now probably not field serviceable due to the tiny screwdriver now required. Tyler has run these on a test rig and realised over 1500 inflation cycles. Considering the early motors could inflate a Thermarest Winglock pad an average of 103 cycles (around five hours) before the motor required replacement, this is a considerable improvement and should be enough for most users with no need for field, or even home repair. One final note on this, the inflator can now be reversed and used to deflate a pad.
Tyler open-sourced the design specs of earlier Pad-Pals. While he still intends to do this with future iterations, he is keen to recoup his expenditure through a few sales (some 600 units) before the design is taken on by a big-player, tweaked, and becomes a stock commercial product. It has already become apparent that the buyer for the Pad-Pal is not necessarily the ultra-lightweight backpacking demographic, instead, it is also attracting the lightweight crowd.
A proportionally large part of the weight and bulk of this miniscule inflator is the detachable valve adapter required to attach it to the many makes and designs of sleeping pad. v4 had adapters supplied that fitted various pads from Big Agnes, Exped, Nemo, REI, Sea-to-Summit, Thermarest and others. Tyler is experimenting with a lighter and softer material to construct valve adapters from but to date, has only produced an adapter that fits the Thermarest Winglock valve. Others will no doubt follow. The softer, collapsible adapter supplied with the prototype v5 inflator is more difficult to fit to the valve. It works best to wrest it onto the valve itself, then fit to the inflator. I have also found that it is easy to make it deform and collapse inward, thereby fouling the fan in operation. While the soft valve adapter is designed to collapse, there is the option of using either the slightly heavier rigid adapter produced for the earlier variants of Pad-Pal or a new but similar rigid adapter that Tyler has somehow been able to shave just a little weight off. As to weights, the older, more rigid adapter for Thermarest Winglock valves weighs 2.33g, Tyler’s further development on that has reduced this to 1.77g while the new flexible adapter weighs 1.16g.
Unlike other battery inflators that have an internal battery, the Pad-Pal has it’s weight much reduced by relying on power from a powerbank, something that most campers and backpackers will include in their gear. The v5 prototype has four power modes, on the third mode, about 28mAh is required to inflate a NeoAir Xlite NXT regular sleeping pad. This equates to around 280 inflations from a 10k powerbank, or around 4.5% of a 10k power bank over a week assuming two inflations a day.
My v4 Pad-Pal was not a cheap purchase and no doubt the new v5 version, when it does surface, will also be a pricey purchase, but for those looking to shave off the grams, they may decide that the cost is acceptable. Despite almost no advertising outside a single r/ULGeartrade post, Tyler has received more interest than he had initially anticipated and has sold around 280 units of his earlier versions with further enquiries about what is to come. His last batch of 100 v4 Pad-Pals sold out in three days. Relatively small numbers perhaps but this is a niche product that has been gathering interest. Tyler is aware that the online ultra-lightweight community is quite small and a poor product, or a product negatively perceived, can quickly fail. This is why he is taking it slow and adapting and tweaking the design in the early stages to reflect the feedback he is receiving from users. Alongside this, he has been co-developing an automated assembly method as he does not want to be limited to his personal output capability if and when sales kick off in good numbers.
There is a phenomena whereby people will enthuse on an item because it cost them a great deal of time, effort or money. This is a form of mental justification and is probably encountered more often that we might like to think. However I do believe that the Pad-Pal is one of the most innovative pieces of ‘new’ gear introduced to the outdoors gear market in many a year. Watch this space.
As I have said in another post I am really interested to see what 3D printing can do going forward.
The big companies are using 3d printing to massively increase the price however the process gives us complete customisation.
For example could they not give you a version with a USB-C connector.
The Pad-Pal does, of course, have USB-C
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It is a lot smaller than I thought it was.
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I have not seen anyone talk about weight vs strength and type of filament?
There are carbon fibre filaments so how light could you go?
Imagine a rucksack with 3d printed dyneema cord straps instead of webbing or a L shaped back plate with a ripstop fabric rucksack which is sewn through the holes in the plate.
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You really are talking right outside my present knowledge. As always, I am incapable of giving a sensible, informed, knowledgeable or even entertaining reply. My apologies