Jacob's 33 chuck issues in Craftsman Drill press

[AndyNC]

Hi All,
Seasonal greetings.

Had a chance to examine my Dad's old Craftsman drill press. I've had it years and it's always had a problem with drills not being centered.
So Father Christmas brought me a magnetic base and dial gauge so I've been measuring a few things.

The only number I can find on the drill press is 101.03581 and I can find a reference for it.
I found this website for craftsman spares but the diagrams for anything that looked similar were not good.
http://www.searspartsdirect.com/partsdirect/brands-products/Craftsman-Parts/Drill-Parts#targetAction

I've measured the taper and it has 0.05mm runout. The exterior of the chuck has 0.12mm runout and a drill (Dormer 9.5mm) in the chuck has 0.19mm runout near the jaws. Obvious with a 2mm drill this is way out.
I've mic'ed up the taper as well as I can with the quill in the machine and it seems to be a JT33 but I'm not experienced enough with a micrometer to be sure. I can read a mic easily but it's getting the tool square on that's the issue.


I mainly do woodwork and some metalwork have found that the existing run-out to be and issue. eg when making plugs for counter bores, at nearly 0.2mm run out you get 0.4mm error between the pairs and it forms a ring.

Preamble over: it come to two questions
1) Would I be right in assuming that the chuck needs replacing or are there some other hidden issue that may cause the run out?
2)Where can I get a Jacob's replacement in the UK or are there some 3rd party products that are worth buying?
I've found this https://www.cromwell.co.uk/index.php?q=0&p=viewproduct&i=KEN4401450K&message=addtobasket but I'm not sure of the quality.

Many thanks

Andy

Edit: It does not have a removable mandrill, least ways there's no slot to allow a taper removing drift so it seems I'm stuck with the taper.

 

[carlb40]

Loads of jacobs chucks on ebay

 

[AndyNC]

Hi Carl,

I agree, but at the moment there's only a few 33's and they are second hand.

I'm after a new one because I have a second hand one and it's not much good.

Cheers

Andy

 

[Doug B]

http://www.rdgtools.co.uk/acatalog/DRILL_CHUCKS.html

 

[RogerP]

2)Where can I get a Jacob's replacement in the UK or are there some 3rd party products that are worth buying?
.

Got fed up with the run-out on existing chuck so bought a new Ref: 758 chuck and arbour from RDG Tools
http://www.rdgtools.co.uk/acatalog/DRILL_CHUCK_S___NO_ARBOURS__.html.
Very pleased with the result - no discernible run-out.


EDIT - same as Doug

 

[Myfordman]

The problem is that all the RDG chucks that have female tapers use B series tapers (which are defined as short sections taken from Morse tapers) Looking on the Jacobs website, most, but not all, 33 series chucks use JT33 tapers and that has got to be a spot on fit.

J& L industrial list 10, 13 and 16mm chucks with JT33 tapers. These will be professional chucks and not cheap

Arc Euro trade list only one JT33 chuck and that is a 13mm keyless. Their stuff is normally pretty good quality- just depends if you want a keyless.

0.05mm run out on the taper is not that good. You need to decide if the spindle has got bent or if the bearing need replacement or adjustment of the preload if the machine design allows this.

 

[AndyNC]

Hi,
Thanks for the suggestions of RDG tools. I've emailed them to see if they have a Jacobs 33 equivalent. They don't seem to have one on their web site.

Myfordman: Thank you for your comments. I think the taper on the drill press is not that good, it looks a bit scratched. I recall my Dad ( who has a ML7 sat in his garage in Cornwall not being used while I live in Berks) said he had problems with the taper/chuck and had to drill into the taper and add a screw to hold the chuck in. So there could be problem with the taper. The drill press is very old potentially 50 years and getting a diagram to show how to break it down seems difficult. The Sears site drawings are very poor and I can't identify the model. Unfortunately the taper is not replaceable.

You are saying that 0.05mm is not that good, but if I put on a new chuck should I not get a lot less than the 0.2mm I get now or is this multiplied up. I can well imagine a bent spindle would worsen the effect the further from the chuck you get. I suppose I should put the drill in upside down and measure at the bottom of the drill. If it's still 0.2mm I would assume the spindle is straight. A job for tomorrow morning.

I looked up the Arc Euro site and they sell a JT33 chuck (keyless) for £22 (+vat?) which i think is a lot cheaper than buying a new drill press and about 1/2 the price i found for a JT33 keyed at Wokingham tools at £40. If this gets the error down to 0.05+chuck error, £22 is quite a cheep fix in my books. I'm not looking for perfection but at the moment it's not adequate for what I do.


Cheers

Andy

 

[SteveW1000]

Hi Andy,

For help in identifying your drill press you could try asking at the Garage Journal an american forum where there is always a lot of discussion on all things Craftsman. I would be surprised if the chuck mechanism is faulty they generally don't get the wear that lathe chucks get, the internal tapper may be scoured or dirty it also may be dirt inside they can be taken apart for cleaning and lubrication. If the spindle isn't bent it may be possible to get a descent machine shop to re-machine the taper. For future information micrometers don't generally work well on tapers, we were taught on my C&G course that you used a ball bearing or rod between the anvil of the mic and the surface to give a point contact, with a bit of trig you can get the measurement with mic accuracy.

Hope this helps.

Steve

 

[AndyNC]

Hi All,

After much mulling over what to do I decided to take the plunge and bought a Myford chuck which comes with a MT2 to JT33 adapter.

I fitted it and it runs out just as much so it's either the taper or the spindle.

I've looked carefully at the taper and it seems to be either worn ie it spun in a taper or it's been re-cut on a lathe also my father had issues with the taper I think the problem lies there.

Now the big question it to get it fixed and how. I would imagine I can get the taper re-ground but I have no idea what that would cost.

Has anyone had this done before and have an idea of cost or would it be cheaper buying a new/sh one.

Cheers

Andy

 

[GLFaria]

If you still need to make sure, the size of the cone should be engraved od the chuck body.

I recommend that you buy a keyed chuck. These are the only ones to mount on a small or medium DP. On these DP's, keyless chucks simply won't let you tighten hard enough to be sure about the grip on large diameter bit or a hole-saw (that is, unless you are willing to spend a lot of money and buy Röhm or Albrecht...)

 

[AndyNC]

Thanks for the response.

I see now I didn't word my question well.

I have replaced the chuck with a Myford one. Which is keyed and of presumable good quality being made/sold by Myford. Also the error is similar to the existing chuck so I think I've ruled out the chuck.

It's the taper on the spindle that seems worn/damaged.

Further measuring shows that the top is 0.05mm out and it get worse lower down the taper as much as 0.1mm.

I was wondering if anyone had had a spindle taper reground?

Cheers

Andy

 

[GLFaria]

I don't think regrinding the spindle taper to be a practical, if at all viable, proposition. If the run-out is severe, usually there simply is not enough material do do it properly. Even if there is, most likely the spindle has suffered some kind of abuse. In that case, the arbour - and possibly the bearings too - may be damaged. I would go for a replacement spindle. But maybe you can find some local engineer or mechanic who may give you better advice after actually looking at things.

I don't know how you measured run-out, so here goes the way I did in case it may help. If you can borrow just a dial indicator, you don't need a sophisticated stand or magnetic base. I made the indicator "stand" from a wooden shelf bracket I happened to have lying around. Measuring at different locations along the cone length was done by displacing the table up and down.

 

[Spindle]

Hi

I don't have any drawings pertinent for this drill but it is quite often the case that the Jacobs taper is ground onto a Morse taper that is in turn mated to the quill. If this is the case with your drill I'd suggest removing the Morse taper from the quill, (there will either be a slot aligned with the top of the taper into which you knock a wedge or you will need folding wedges between the JT and the quill). Once extracted examine the mating surfaces of the tapers for corrosion and debris, clean, re-assemble and re-check out of round. Try this in several positions to see if it improves in any one location.

Regards Mick

 

[AndyNC]

Hi

Spindle: The taper is part of the quill and not removable as such. It's definitely a JT33 because I've measured it to give an approximate check and also it was fitted with a JT33 chuck.
GLFaria: I measured the run out using a stand and clock gauge similar to your arrangement. The age of the drill is such that a re-placement is unlikely but if it uses standard ball bearings there should not be a problem changing the bearing and straightening the quill is always a possibility (see below).

I looked around for the price of re-grinding the taper and was a bit shocked buy some of the figures given on USA forum.
So I googled in the UK and picked one at random in Coventry who would do it for mates rates as I was not a company. Ok, I've still got to get it done and see the results but he seems to know what to do and regularly re-conditions spindles. He also said he could straighten a spindle if necessary. He also wanted me to supply a chuck so he could match the taper to it and with bearings so everything would be lined up.

My next issue is the dismantling of the drill press. I can't find any drawing so I'll have to find typical drawing and use it a s a guide. I'm making the assumption that Craftsman did not change the fundamental assembly during the various models so any similar vintage unit would probably be close.

Unfortunately I won't be dismantling it for at least a week because I've some new racking on its way and I need to re-organise my garage/workshop to make way for a wood lathe(yipee!)

Many thanks

Andy

 

[AndyNC]

Done a bit more searching and found some info on Vintage Machinery site. It seems to be a 101.03581 Craftsman/Atlas Drill Press dated 1938 and I've found a assembly diagram for the 101.03662 Craftsman/Atlas Drill Press which looks very similar and would be a good guide.

http://vintagemachinery.org/pubs/222/572.pdf and http://vintagemachinery.org/pubs/222/928.pdf if interested.

If any one's dismantled one of these before I'd love to know.

Seems to me that the drive pulley needs to be removed first then the pinion. The pulley seems to be held with a srew on the second from top V and the pinion spring by a bolt in the bottom.

According to the prices I should just buy a new head unit for $23.75, easy.

Cheers

Andy