Back in August the subject came up. Unless plumbers are putting plastic pipes in notches, there should be a growth in sales of these drills. My own Hitachi 400w has suffered too much over the past few months. Stalls are infrequent but do happen with flat bits, and it can't survive them. New armature required, about £65.
There is a poor number of choices on the UK market. There's the Makita 6300 (piccy last August), BES do a Hitachi of similar spec, and I have seen a Milwaukee, once. They are all much cheaper in the US, and there are bigger drills available which will drill holes of impressive dimension. The BES Hitachi seems to be a one-off, so I imagine I'll be after the Makita unless I can get assurances about spares.
Again in the US, the bit of choice seems to be a "Selfeed", which looks something like a Forstner bit with teeth, up to several inches diameter. It seems ridiculous to have to import something like a drill bit, but there are a few web sites which will oblige. Does anyone know of a similar bit in the UK? I have seen the "MAD" Multi Angle Drill, but found a 25mm unspectacular in use, and they don't go big enough.
Hitachi power tools have been available for some time in UK so there shouldn't be a problem with spare parts.
Regarding drill bits would suggest you phone Axminster Power Tools, or access on net www.axminster.co.uk they sell (page 5.12/3) sawtooth cutters similar to Forstner bits so may well be what you are thinking about. They sell sizes up to 3inch with a 1/2 inch shank so should fit most drills and definitly better than flat bits.
They sell right angled drills as well. Well worth getting a copy.
Been there, but didn't see the bits, thanks. They don't do the big angle drills. By one off I mean BES is the only place in the country which sells that tool. It's really a fairly standard drill with an angle attachment though.
In the US there's a thing spelled like it's pronounced like "whole hog" but with a Texan accent, "hawl horg" or similar.
Hmfff. Time limit expired so edits lost..
The Axminster one sounds right but there's no pic on the web.
Chris, why are you drilling large holes in joists? My fear is that a weak joist could bite you later (that is when the floor goes). There is a BS which gives max sizes for holes, but as I write this I have not looked this up.
Don't waste your time with a right angle drill!
Buy a right angle drill attachment instead - it fits on a standard drill (ie with a 43mm collar)
Take the chuck off, fit the right angle and screw on the chuck again. The attachment spur gear ratio lowers the drill speed but increses torque. Typical 550 W drill goes like a 700 W. I've used it for years, very tough and withstands loads of abuse. Easily drills through 4" joists. Also cut down your flat bits when the joist are a bit close.
The WB707 angle head is available from Impact Power Tools by mail order on 01737 772436
A few years ago it was around £70.00
Geoff that's what I've been looking for but had given up. Would be good with a 1400W diamond core drill... There is one site in the WORLD which shows it -Axminster tools again. My fear is that it has been discontinued, I've been caught by their catalogue before. IPT don't list anyting like it. I'll report back if I can get one. This appears to be it (now I've found that showing images does work for me I'll be using all Les's space..
Bernie some of these things I have learned parrot fashion, if not quite the way expressed in the BS. You can drill holes up to 67.5mm diameter! Biggest I've ever made were for waste pipes, but still not that big! Max dia is 25% joist depth, or the 67.5 whichever is less. Have to be betweem 25% and 40% of span length from end support, and on longditudinal centre line (the "neutral axis" which in fact rises towards the ends).
Notches by the way are limited to half the hole dia figure (iemax 32.5mm) or 12.5% joist depth whichever is less, and have to be within 7% and 25% of span length from support.
I find the "hole" rule easier to abide by than the notch one. If the rad tail falls on a joist..
Funny things, joists, the stiffness (=strength in popular parlance) is proportional to the cube of the depth, so a 10" is twice as stiff as an 8", and the edges do most of the work, hence "I" beams, bigger holes than notches, etc.
As I used to be an engineer, I did some maths a few weeks ago. If you consider a joist 150mm deep to have a stiffness of 100% and then you cut a 30mm notch in the top, you reduce the stiffness to 50 something %, but if you cut a 30mm hole in the middle (neutral axis)it is reduced to around 99%.
51.2%, and 99.2%? and even the "maximum" depth/4 hole only weakens it by 1.5%? Max D/8 notch weakens by 33%!! Someone else remembers Second Moments of Area! Barry would you agree that a notch at the top of a beam near to the end, where the beam is supported in the normal manner (underneath!), is less weakening than one in the prescribed 7-25%? Reasoning being that it's nearer the neutral axis.
The rules get trickier if there's a third support somewhere along the length.
Check out B&Q warehouse for their latest toy ,A 500w right angled drill for £45.A pal of mine bought one so naturally I tried it out and am just going to our local B&Q to purchase one.
Having paid out for tha Makita DA4000LR I would enjoy much schadenfreude if the B&Q jobbie stalls and burns out the first time you try a 32mm flatbit in a joist. But check the rpm - if it's lower than 1500 or so it might be OK.
The Makita is up to 900 rpm, which is good with Selfeed bits which just munch their way through.
Chris,can I try your makita as well??
Very interesting stuff. Please elucidate on the Selfeed bits.
Some superb images above and I don't know how I've missed them before. We have tonnes of web space so don't worry about posting images.
Been fantastically busy but have now created some space and burned a load of CDs. Apologies to anyone waiting. They will go out this weekend.
Selfeed bits are US made, as pic way above. Key (!) is the central shaft which comes to a screw-threaded point. Pull the bit in in much the same way as most moders auger bits do. Main difference is that they're very short. You can easily get auger bits in short pattern - if you hunt anyway, up to about 1 1/2".
"self" feed is a bit of hype, you still have to push somewhat but less than with a flatbit. I've mislaid the useful ones around an inch, still got a couple of bigger ones handy. I have seen them in use in UK but don't know where to buy them here if Axminster's ARE different. Got mine while skiing in Colorado.
Guess I could take orders - probably returning next Feb! Came back with a number of US only widgets last time. A favorite is one which obviously cannot work. Added to my collection of tools-which-never-stood-a-chance. At least I don't have to pretend it'll come in handy one day.
I got the £45 B&Q drill detailed above some time ago and only had a chance to use it last week.
I used it myself and would not let anyone else use it, as it's 240V.
I was installing JG Speedfit heating pipes through joists at 300MM centres!!
It worked quite well with just a 25mm flat bit and with it's 500w motor there was no big kick. However, I'm not sure it would last long with continuous use or large drill bits. I think it will be quite a handy wee tool for working in and around kitchen units. But being 240v does concern me.
Thanks for reading.