Thread: Tough Drill Press Pinion Replacement Query

I have acquired yet another Tough. Pretty much a whim purchase based on the good condition of its pressed metal belt guard.

IMG_20190531_163240774_BURST000_COVER_TOP.jpg

The drill's table, lunar in appearance, along with only one loose epoxy "fixed" capstan handle. the other two having been sheared off, didn't cause me too much concern because all I really wanted was the guard and the main head casting.

Turns out the Tough changed the head casting from my intermediate pulleyed 12 speed version having a pair of column pinch bolts to a single fixing on the "new" 4 speed drill. The new drill also has a space saving direct mount chuck. So I thought that having a pair of interchangeable quills could prove handy. Handy if pinion wear didn't prevent their interchangeability. The new drill's pinion teeth have been damaged -

IMG_20190531_152101833.jpg IMG_20190531_153213543.jpg IMG_20190531_164330622.jpg

The capstan hub will probably require replacement due to mutilation of the thread where epoxy was optimistically used in an attempt to secure the handle. Removing the mess involved some fanciful clamping -

IMG_20190531_133132196.jpg IMG_20190531_133139487.jpg IMG_20190531_152122435.jpg


So with the background to the query hopefully explained I am wondering what those versed in these things would choose to use as material for a replacement pinion.

I was thinking of 1214 because it would probably be softer than the material F and R Tough used for the quill.

Bob.

Hi Bob
I would have said creative clamping.
I'm not an expert but probably forget any of the plastics. not knowing how tough the quill is I would say you aren't too far away from the mark with the 1214, maybe free cutting? Or is 1214 free cutting?
Told you I wasn't an expert
At least it's relatively easy to replace as the sacrificial piece.

Phil

I would probably use aluminium bronze because its a beautiful material to work with. Its expensive though.

I have a piece on hand that might do the job what are the dimensions?

Otherwise I don't like the 12Xxx materials as i never get good surface finish and also find the corrode very quickly. I would probably just use annealed 4140?

I had a quick look at the photos, is it only 1 tooth? If it is, was it done in the machine or has someone dropped it dismantling it in the past.
I'm am sure what ever steel you use will last our lifetimes and probably more.

That's my thinking of a new cross slide screw for my lathe to fit the taper attachment, just need something that will leave a smooth surface finish. Having the DRO cancels out and screw error, so if I wanted to be crued I could use Bunnings thread rod, lol

If that is just the one damaged tooth, have you considered repairing it. If the parent material is unhardened you could possibly just run a weld bead along it and recut the tooth, or if it has been hardened, perhaps it could be built up with silicon bronze and then recut. I have also seen repairs (where a tooth was completely broken away) made by drilling and inserting pins which were ground to the tooth profile. The picture below illustrates this method. It is hard to imagine just how the pinion sustained that damage, but I think that any repair need not be overly technical, and should be easier than a whole new pinion fabrication. Good luck.

https://images.app.goo.gl/bJEmSUH613246J9F8

I'd use some carbon steel - 1040 or similar. 16T, 16DP.
Do you need a cutter?

Michael

Another thought - if it is one tooth, would a bit of heat and some work with a punch knock the tooth back to where it should be?

That damage is not that bad (at least from looking at the picture). I'd braze it up then die grind/file it back to shape. It wouldn't have to be perfect. Its not like its a high speed or high load gear train.
peter

Thank you all for the replies and suggestions,

There are three damaged teeth and while they could be repaired I don't have the facilities to undertake those repairs.

IMG_20190709_091517677.jpg IMG_20190709_091544441.jpg IMG_20190709_091613786.jpg

Fortunately the quill's rack teeth appear to be in reasonable condition though there is some galling.

IMG_20190708_134523667.jpg IMG_20190708_134612183.jpg

While it is evident that someone has had the quill apart I was heartened to find that the spindle's Jacobs taper nose had no more than 0.00025" TIR.

Today I turned a small portion of the pinion end and the turned finish looked much like the finish I've encountered when I have turned 1045. It appears torn. The loupe photo shows the tearing clearly on the surface sandwiched between the original outer surface and the inner newly turned surface.

IMG_20190709_091159352.jpg

I had a look at the two gear catalogues I have published by Hercus and HPC Gears in England and found that Hercus make their pinions from 1045 and HPC from EN8 (1040) so now I'm starting to lean away from the 1214.

I posted this thread after the cutter I purchased on eBay arrived from China. The packaging I thought was worth photographing.

IMG_20190620_151853248.jpg IMG_20190620_151955017.jpg IMG_20190620_152020685.jpg

The cutter has a 22mm bore so I made stopped end sleeve to clamp the cutter to a Vertex indexable face mill arbor Michael G supplied me with a few years back.

IMG_20190709_091749692.jpg IMG_20190709_091949090.jpg IMG_20190709_092111476.jpg

Nearly ready to go gear cutting !!

BT