Corded adapter for HKC saw.... any chance?

[demographic]

Currently I have a HKC which I use a lot.
Nice machine and if a dumper ran over it I'd buy another straight away.

Thing is , De-Walt have made a cordless site saw with a cord with a battery fitting that you just put into the battery slot so converting the tool over to corded.

Got me thinking... if Festool made one of those I could run the saw in a workshop setting without faffing on charging batteries and I could connect it upto the extractor and have it autostart when I'm cutting but then remove it when I'm away from power and just use the dust bag.
Win, win.

So, is there one in the pipeline?

 

[Gregor]

I suggested that to festool (the german site has a form for ideas) and got a lengthy answer from one of their engineers. Gist was:

High power (current, as of the low voltage) requirements would make it bulky, heavy, prone to overheating and expensive to produce. Estimated retail price would be above what several (3+) battery packs cost, resulting in them not seeing a market for it.

If it would exist I would have bought it and a HKC, TSC and PSC by now - as it dosn't I just got a drill and a handfull of (non-festool, but waterproof) 10m extension cords. Sad thing for their bottom line, but what can I do...

 

[AlexThePalex]

[member=53905]Gregor[/member], can you please post the link to that reply? Sounds interesting and I would like to read it.

Odd if DeWalt can do it, but not Festool.

 

[antss]

Funny how the silly Dewalt wonks can figure out how to make one that fits their standard battery pack size, is of an acceptable weight to users, doesn't overheat, and makes the marketing department and the bean counters happy but........

a heavy , expensive,  heat producing edgebander that cost more than alternatives is totally within the wheelhouse.  [doh]

 

[Euclid]

The weight/bulk argument seems a bit spurious: once you've decided to attach a cord to the tool, haven't you removed the requirement for the 'transformer' to be physically mounted on the tool? Any number of less-than-mains-voltage devices have external power supplies sitting inline between device and mains socket (many, admittedly, with less current being drawn).

Once it's an external box it can have a decent-sized heatsink without compromising the ergonomics of the tool. Or maybe mount it in a Sys-Powerhub with a fan?

I'm not sure that price would necessarily be a barrier to purchase - it's not as if you'd want to buy a whole stack of them - though I can only guess at the size of the market.

 

[Rip Van Winkle]

Dewalt isn't the only company to manufacture a corded adpter for their cordless tools, or at least to have a corded adapter made for their cordless tools.

Some Greenlee cordless tools use Makita batteries, and Greenlee sold an adspter to allow the cordless tools to be used with a 120v power supply. You can find the adapter on Amazon, but it's around $300, and some of the reviews complain it can't can't convert enough power for higher draw tools.
https://www.amazon.com/Greenlee-EAC18120-120-Volt-Adapter-Cordless/dp/B004I0Q5PC

The Dewalt power supply adapter is only around $50, and there aren't many reviews I can find yet. The one review on Amazon sounds like the adpter may not work for some tools, but it's hard to tell without more reviews.
https://www.amazon.com/gp/aw/d/B01H...81029420&sr=8-2&pi=SY200_QL40&keywords=Dewalt+flexvolt+120&dpPl=1&dpID=41NUdEp5hNL&ref=plSrch

There is a German battery company, called Akku Power Gmbh., that assembles battery packs, and makes industrial chargers for a number of brands of power tools. They manufacture power adapters for several brands of power tools so the tools can be used on regular mains power, but I presume they only manufacture the adapters for Euro 230v. The battery brand types they manufacture the adapters for are, Bosch, Makita, Panasonic, Hitachi, AEG/Milwaukee/Atlas Copco, Gesipa, and Elu. Some of these may only be for older type batteries. I suspect these are manly purchased by companies that use cordless assembly tools in industrial settings so the adapters may only be capable if lower current draw, but since I live in 120v land I don't feel like spending 200 to find out.
http://www.akkupower.com/products_mainsconnector.aspx?lang=en

 

[Gregor]

The weight/bulk argument seems a bit spurious: once you've decided to attach a cord to the tool, haven't you removed the requirement for the 'transformer' to be physically mounted on the tool? Any number of less-than-mains-voltage devices have external power supplies sitting inline between device and mains socket (many, admittedly, with less current being drawn).

Once it's an external box it can have a decent-sized heatsink without compromising the ergonomics of the tool. Or maybe mount it in a Sys-Powerhub with a fan?

In case my assumptions are not totally flawed and I got the math right:

Let's say a TSC55 with two battery packs lasts for 10 minutes under load till they're fully depleted (just pulling up that number from thin air with as inspiration).

With 93.6 Wh per battery pack (18V*5,2Ah) and the need to go through 12 (as we empty 6 pairs) per hour we're at 1123.2 W average power consumed. This is near enough to the 1200W rating of a TC55, so this should be in the right range.

1123.2W load equals to 31.2A current (@36V) being drawn on average. Thus we need thick wires to stop them from heating up or emitting visible light. This leads to a cord that is heavy and not really flexible, so the idea with an external transformer dosn't seem feasible unless you completely ignore any ergonomics when handling the tool.

 

[Euclid]

Ok - thanks Gregor. That was really why I posed my thoughts as a question - and the comment about current; I wasn't wholly clear on how to work out the exact cable requirements (and I had overlooked the 36V situation) but suspected there might be issue with necessary gauge… and I agree, that could be a major set-back.

I'm glad I posed the question though, because I've learned something!

 

[amt]

You might be able to do 31 Amps with 10 gauge wire, but that's getting quite thick.  And I am not sure if the saw really runs at 36v, or just 18v with twice the amperage from two batteries.  If it's 18v, then even thicker wire is necessary.

This is where Dewalt has done their homework.  They run two 60v batteries in series for 120v, so their wire sizing requirements are likely no different and 120v A/C

 

[Gregor]

This is where Dewalt has done their homework.  They run two 60v batteries in series for 120v, so their wire sizing requirements are likely no different and 120v A/C

When the tool only needs a bridge rectifyer and a cap to filter the ripple and then can be directly connected to mains voltage the solution can be simple as it only needs a case with matching contacts.

 

[antss]

18v & 36v don't require all that thick of a wire.  Just how big do you think the wires inside the handles pf the drills and saws are that connect the switch to the motors ???

These saws aren't pulling that many amps such that a 14 or certainly a 12ga supply cord to the transformer wouldn't be suitable.  That's the gauge on an large router or framing saw and no one seems to object.

 

[amt]

18v & 36v don't require all that thick of a wire.  Just how big do you think the wires inside the handles pf the drills and saws are that connect the switch to the motors ???

Those wires don't have to be 12+ feet long

These saws aren't pulling that many amps such that a 14 or certainly a 12ga supply cord to the transformer wouldn't be suitable.  That's the gauge on an large router or framing saw and no one seems to object.

The amperage needed  is inversely proportional to the voltage, so I think they would need the higher gauge wires.  Then again maybe I am wrong, Festool is wrong, and Dewalt ran 120v for no good reason, and you are right because you saw a small gauge wire on a tool one day...

 

[antss]

You're suffering from analysis paralysis.  The connection at the actual tool doesn't need to be heavy or have overly thick wire, or be large.

Now , what happens inside the actual ac/dc converter box is another matter as is  its size and weight and price .  So, I can kinda see FT's conclusion not to pursue.

This problem has been solved before, though I agree Dewalt has cleverly applied the science. They tried this a few years ago with a 24v saw if I remember correctly.  Ryobi had a couple of hybrid tools like this too at 18v.  Neither gained much traction.

Low voltage tool power supplies.