A new chuck on the block

[Blogwitch]

While I haven't been able to work in my shop, I have been scanning the internet looking for a few items to replace worn out ones on my machinery.

One of the items is an Albrecht tiny keyless chuck.

A while ago, I was given a high speed drilling machine, unfortunately the chuck on it must be about the same age as the drill (I would say mid 1980's) and it doesn't hold real tiny drills any more as the jaws are worn.

So having found a few places on the net where I could buy a new one, and after picking myself up off the floor a few times when I saw the prices they were charging for them, around 80 pounds UK.

As I was wandering around the Chronos site, and looking down the new items list, I found some Chinese ones that I had never seen before. So I duly ordered one to have a look. As soon as I saw the quality of the build, I bought another couple straight away. They are about 1/6th of the cost of the Albrecht offering.

As you can see on this pic, they look to be an almost exact copy.

Just a couple of differences, the new ones only open out to 3mm, but that is perfect for the tungsten drills I will be mainly using.

The other is that they are JT0 mount rather than the JT1 mount of the old one. But, in fact, that works to my advantage, because I can machine the new size mount into the back of one of them, and if mounted onto a high precision mandrel whilst machining, it should take out any runout that might be present.

One of the two remaining is earmarked for a lathe tool I have been wanting to make for a while, and the last one will go into stock, just in case something else comes up requiring a tiny chuck.

Bogs

 

[Deanofid]

They look nice, John. I'm not surprised they look just like the Albrecht. Surely that's the chuck they bought to send to the "reverse engineering department". It's what I would have done!

When you mentioned machining the mount, do you mean you would tighten the chuck jaws to a mandrel, then turn a JT1 taper in the back end? I take it that part is not hardened, then?

Just an aside; I don't remember seeing your hands so clean. : )
Hope you can get going in the shop again soon!

Dean

 

[Blogwitch]

Dean,

You are quite correct about the mandrel, I have used that way many many times, and with care you can true up almost any chuck that has a bit of runout. You just have to make sure that your cutting doesn't deflect the mandrel.

I am in the enviable position of owning a toolpost grinder, so hard or soft, it makes no difference. I will see if it can be bored with a normal tool first, as that is the easiest way.

For those of you in the US, LMS do a very good range of reasonably priced toolpost grinders. Almost one for each depth of pocket.

http://littlemachineshop.com/produc...?critFast=tool+post+grinder&B1=Product+Search

An internal grinding mandrel is easy enough to make up. Stew shows one in his toolpost grinder making post.

http://www.homemodelenginemachinist.com/index.php?topic=6437.msg68893#msg68893

You can then use the grinder like a precision toolpost drill as well.

For jobs like this, where you require ultimate accuracy, or machining materials you can't normally machine (rubber, plastics, hardened parts etc) they really are a reasonably priced item that can get those seemingly impossible jobs done.

A few minutes after this shot was taken, my hands were getting dirty. I managed to do a tiny bit to the gas jet needles, but had to stop after about 30 mins. But this coming Monday brings a new trial med, and I will have to see how that affects me, to the better I hope.

Now if anyone ever wants to service their Albrecht chuck, this site shows just how to do it.

http://www.machinistblog.com/?p=1813

Bogs