Imperial drill bits. One and one eighth of an inch

TheMarlin

I’m modding a turntable (adding TVA adjustment), but need to widen a drill hole to one and one eighth of an inch. 

Material is woodchip/MDF -  but can’t find the right size drill bit for love nor money. 

Can anyone loan one to me, will return it next day (tracked and traced) with a set of stings as a thank you. 

Thanks for any help offered. 

Marlin

Roland

What tolerance do you need, ie would 30mm be OK?

TheMarlin

Has to be a tight fit, as it’s one mechanism to secure the arm, and adjust the height. Loose fit will result in floppy arm... so close as possible...

strtdv

https://www.ebay.co.uk/itm/Large-Imperial-Drill-3MT-Shank-1-1-8-28-6mm-dia-Lot-224-/282800529554

There you go

TTony

1 1/8" = 28.575mm

You can get 28.5mm drill bits here ...
https://www.ebay.co.uk/itm/5x-MORSE-TAPER-SHANK-TWIST-DRILL-BITS-12mm-38mm-HSS-Steel-Drilling-Metal-Bit-Set/401788392212?hash=item5d8c745314:m:mAa5b2LrZhbUvqKMqYZ1ncA

... or a few other places on evilBay.

TheMarlin

Cheers guys. Those are drill bits for steel. Ok to use in wood?

Rocker

Those bits are for drills with morse taper fittings.  They are not suitable for use in a standard drill chuck.  Somebody with a lathe might be able to remove the taper but this is not something that might be possible if the taper area is hardened steel.  If not then check with engineering firms in your area to use their drill machine with the morse taper bit.

Otherwise contact the TT manufacturer, they may be willing to drill the hole for you.

Corvus

^wis'd. ~28.5 is going to be hard-ish to find I should think, search for straight or reduced shank. Drill bits are slightly crude weapons but MDF or chipboard's not going to be that precise anyway.
But a Forstner bit will almost certainly be out there and more accurate and clean, but need a drill press and a way of centring it. Holesaw too probably but same thing, needs centring somehow.

One way - need a drill press and a cutter mounted that fits the current ID. Move the piece so the cutter fits in the hole and clamp the piece down. It's now centred, so raise up the drill head and swap to the cutter you want.

richardhomer

You’re in good company - apparently Jacob Rees-Mogg will only allow imperial measurements....

bazxkr

@TheMarlin  

How thick a material are you going through ?    

Take a look at 1 1/8" hole saws. Thicker walled long tube type not the thin walled shallow ones. USA still uses imperial tooling as does some oldUK machinery so still a ton of imperial stuff still available. I don't know how accurate on dia they are manufactured to but the better quality ones should be good and within 0.005 but also depends on what drill and how much float in the chuck. I have a set but can't remember if metric or imperial. Will check tomorrow afternoon. Will do a test on whether it is 28 mm or 1 1/8 by drilling some mdf and measuring with a digital caliper. If it looks good happy to send you the tool and the test piece so you test the hole with the arm before you drill turntable. Will me early evening tomorrow I guess. 

Sassafras

TheMarlin said:

I’m modding a turntable (adding TVA adjustment), but need to widen a drill hole to one and one eighth of an inch. 

Material is woodchip/MDF -  but can’t find the right size drill bit for love nor money. 

Can anyone loan one to me, will return it next day (tracked and traced) with a set of stings as a thank you. 

Thanks for any help offered. 

Marlin

These stings, will they hurt a lot?

TheMarlin

Oops. Damn autocorrect. 
Beer tokens also available. 

TheMarlin

bazxkr said:

@TheMarlin  

How thick a material are you going through ?    

Take a look at 1 1/8" hole saws. Thicker walled long tube type not the thin walled shallow ones. USA still uses imperial tooling as does some oldUK machinery so still a ton of imperial stuff still available. I don't know how accurate on dia they are manufactured to but the better quality ones should be good and within 0.005 but also depends on what drill and how much float in the chuck. I have a set but can't remember if metric or imperial. Will check tomorrow afternoon. Will do a test on whether it is 28 mm or 1 1/8 by drilling some mdf and measuring with a digital caliper. If it looks good happy to send you the tool and the test piece so you test the hole with the arm before you drill turntable. Will me early evening tomorrow I guess. 

Material is MDF/fibreboard- about an inch and a half thick (Rega Planar 2 turntable)

ESBlonde

I have a set of these forstner bits

https://www.recordpower.co.uk/product/16-piece-forstner-bit-set#.XT73pXvTWUk

Which are detailed to include a 1 1/8" bit.

The real problem is going to be centering the hole over a hole (if the position is critical). And also probably doing so from both sides to the middle to prevent blow out as you go through. You may need to clamp a thin scrap piece either side of the hole and drill a pin size hole right through to line up each side, before attacking with a forstner bit

Cheapest single Bit I can see online is

https://www.amazon.co.uk/Steelex-D1008-1-1-Forstner-Bit/dp/B0000DD0IM/ref=sr_1_18?keywords=forstner+bit+1+1/8"&qid=1564408263&s=gateway&sr=8-18

Which TBH is probably as reliable a delivery as sending mine back and forth in the post and gets a guaranteed delivery.

If you come unstuck, message me.

TheMarlin

ESBlonde said:

I have a set of these forstner bits

https://www.recordpower.co.uk/product/16-piece-forstner-bit-set#.XT73pXvTWUk

Which are detailed to include a 1 1/8" bit.

The real problem is going to be centering the hole over a hole (if the position is critical). And also probably doing so from both sides to the middle to prevent blow out as you go through. You may need to clamp a thin scrap piece either side of the hole and drill a pin size hole right through to line up each side, before attacking with a forstner bit

Cheapest single Bit I can see online is

https://www.amazon.co.uk/Steelex-D1008-1-1-Forstner-Bit/dp/B0000DD0IM/ref=sr_1_18?keywords=forstner+bit+1+1/8"&qid=1564408263&s=gateway&sr=8-18

Which TBH is probably as reliable a delivery as sending mine back and forth in the post and gets a guaranteed delivery.

If you come unstuck, message me.

As you said, the problem here is centring. 
I’m a ham fisted, butter fingered, homunculus, with a hand drill and a knack for knackering things. . 
Maybe I just pay someone who knows what they’re doing to do it for me. 
Any bidders?

ESBlonde

Shame you were not closer, I'd say pop 'round one evening.

Someone in Bucks should be able to help. Do you know a kitchen fitter?

TheMarlin

No, unfortunately. Oh, well...maybe....

I checked. No. 

Jimbro66

Just out of interest what is the existing hole diameter?

I can’t help feeling that using a hand drill to make a precise 1 1/8” hole through one and a half inch thick board is pushing your luck. Getting a woodworking machine shop to do it for you will probably be preferable to a messed up Rega Planar (nice deck BTW).

TheMarlin

Jimbro66 said:

Just out of interest what is the existing hole diameter?

I can’t help feeling that using a hand drill to make a precise 1 1/8” hole through one and a half inch thick board is pushing your luck. Getting a woodworking machine shop to do it for you will probably be preferable to a messed up Rega Planar (nice deck BTW).

Approx 24mm. About 4.575mm shy of where I need it. Sorry for mixing metric and imperial...

bazxkr

Checked my hole saws today. Teeth are slightly flared so the holes end up bigger than the saw size ie 25 dia cuts 26.15 dia & the 28.0 cuts 30.1 dia. So if I had a 26.5 (which I don't) it would probably cut very close to the reqd size. However I only had 17mm thick chipboard to experiment on. Holes were very clean. The saws will cut 1.5" of depth but I think would wander over that length and not be very accurate. But if had one the correct diameter who knows....drilling from both sides (if an option) from the same pilot hole may get pretty decent. Best way to enlarge a hole is with a router and router bit with a round template but not sure you could adapt that set up on a turntable surface. So sorry at the moment can't help you.

bazxkr

Probably does need the right bit in a pillar drill set up in a machine shop to get the accurary