Help with machining sockets

[scholar]

Hello

I have treated myself to a shiny new drill press - a Nova Voyager dvr - that is very nice (and clever).

My previous drill press was a Record Power model that I was happy with for years.

The Voyager has more power and lots of electronic wizardry that is great, but one change I am less attuned to is the table height adjustment - on the Record, this was a simple clamp on the column that was very quick to adjust, whereas the Voyager has a hand crank driven rise and fall mechanism - this is awkward for my situation, and so I want to add a powered linkage so that I can raise and lower the table.

(I have done a similar thing on my large planer thicknesser where I can drive the thicknesser height adjustment with a cordless drill and 13mm socket, so it will be most convenient to have a corresponding 13mm hex spigot to adjust the drill press table).

I have assembled bits that work, including a right angle adapter that will bring the 13mm hex spigot out through the (yet to be built) supplementary table (which will avoid reaching around/underneath.

I now want to rationalise the linkage assembly which will shorten it and should reduce any slop. This requires some machining that I don’t have the capability to do, so would like to know if anyone could do this.

So the ideal (if feasible) would be to:

a) turn the 1/2” socket in the large lower socket into a 19mm hex socket that would take the 19mm hex spindle on the right angle adapter; and

b) make the hex bit at the top fit in the 1/2” socket of the small upper socket. The hex bit is 13mm on the top end and 14mm on the bottom; it is the 14mm I want to reduce down into the square 1/2”. The 14mm hex is not big enough to fill the corners of the 1/2” square, and I am hoping that this would not matter if it was machined down to a tight press fit - alternatively, I guess a 1/2” square x 13mm hex would need to be machined out of some bigger stock - I have looked for such a thing but have failed to find it.

what do the experts think?

cheers

 

[Derek Cohen (Perth Oz)]

I look forward to seeing your modification.

The hand crank works well, but is large and needs a cut out on the table I added ...

I have used the Nova fence with a sub-fence ...

The round insert allows for an infinite number of holes (just turn it a little). It is a little more work to do, but worth it ...

I turn this in seconds on a lathe ...

Add a Wixey for laser crosses ..

.. and a rechargeable bicycle light ...

Regards from Perth

Derek

 

[TFrench]

The trouble with machining sockets is that they are hardened - will require carbide tooling and a sturdy mill for the rigidity. I think the approach I'd take is to get a 19mm socket, cut the square drive portion off and weld it to the back of the 36mm, and probably surface grind the 14mm hex down to 1/2" square and weld them together.

 

[AndyT]

I wonder if the application needs that heavy duty corner drive? I can't imagine it needing as much torque as a stubborn nut.

So if you leave that bit out, you could have a much simpler setup. You could use mild steel but hard wood would be ok. Get a length of decent rubber hose, enough to go round a gentle corner. Make a pair of pegs, square to fit into the sockets, round to fit into the tube. Actually only one end would need a square end if the other was gripped in the drill chuck. I think you'll find that hose will transfer enough torque to raise and lower the table.

If not, then you could start with a proper flexible drive.

 

[Jelly]

The trouble with machining sockets is that they are hardened - will require carbide tooling and a sturdy mill for the rigidity. I think the approach I'd take is to get a 19mm socket, cut the square drive portion off and weld it to the back of the 36mm, and probably surface grind the 14mm hex down to 1/2" square and weld them together.

Having machined HSS using CBN coated carbide on a bridgeport (successfully, but with a big "lightshow"), I'd be inclined to say this is the best option.

Heating the sockets up and cooling, then machining, then re-hardening would be a good secondary option, but is dirty, messy, faffy and can run into shrinkage issues.

(I once neglected shrinkage from hardening when building a high speed spindle for an engraver, only to find my interference fit became a "flying shards of outer shell" fit as the bearings warmed up from shrink fitting, 30+ hrs of work down the pan.)

 

[AES]

I wonder if the application needs that heavy duty corner drive? I can't imagine it needing as much torque as a stubborn nut.

So if you leave that bit out, you could have a much simpler setup. You could use mild steel but hard wood would be ok. Get a length of decent rubber hose, enough to go round a gentle corner. Make a pair of pegs, square to fit into the sockets, round to fit into the tube. Actually only one end would need a square end if the other was gripped in the drill chuck. I think you'll find that hose will transfer enough torque to raise and lower the table.

If not, then you could start with a proper flexible drive.

OTOH, I was wondering if he would have ENOUGH torque to drive the table up and down AndyT! I'm definitely NOT saying you're wrong (or that I'm right - I just don't know), and of course it all depends on the weight of the table - and of course, on the gear ratio of that right angle gearbox if he decides to use it.

I would only add that on my Rexxon pillar drill, which I modified to add a "proper woodworking" table, the mods necessitated shortening the handle for the UP/DOWN mechanism (to fit the new table addition - I didn't even contemplate adding a powered UP/DOWN drive). The handle mod was basically to roughly halve the length of the handle, and my goodness, you don't 'arf feel "the increased weight" of the table - even though it does still work manually OK.

But I DO like your idea of the "temp flex drive (rubber hose) though.

"Just saying" - no idea if I'm right or wrong.

 

[scholar]

Thank you for the comments and input.

I have concluded that it was fanciful to machine a hex recess in the hardened socket, so will go with Plan A which is to link another socket with a double 1/2” square drive connector.

For the hex spigot, I just ground the 14mm down to fit the square drive socket - did this on the bench grinder, then squeezed it into the socket in my big engineers vice (including a bit of scaffolding tube to add some welly to the handle; I was trying to make it a tight fit and keep it as square as possible, but it was really very tight, so added some heat! it‘s not pretty, but it’s done.

The deep socket will be replaced with a standard length one - £2.64 from Toolstation

This works, holding the assembly firmly, so it is going to need some good bracing under the table - the torque is high, but the cordless drill handles it fine. The right angle gearbox was a (new, unused) £1.99 bargain on eBay and is a 2:1 gearing - I have it in reduction mode.

There will be a little delay before any update: I am away for a bit and need to resolve a mobile base of some sort first. I had not really figured on doing all this when I ordered the Voyager rather hastily and one thing is leading to another...

Cheers