# Jacobs Spindle Nose Chuck



## rebush (May 5, 2012)

Need some advice from the group. Recently bought a Monarch Model K 13x30 lathe. It came with a Jacobs nose spindle chuck and all the flex collets. My problem is the spindle chuck is a D1-5 camlock system and the lathe is a D1-6 system. The PO made some soft jaws for the three jaw chuck, I'm not comfortable with 1/2 inch of clamping area on the Jacobs and the fact that .0035 is the best I get on runout. I'm relatively new to metalworking. I've found D1-6 adapter plates on Traver's and MSC, can they be machined to receive the 7degree 7 min taper for mounting and with the rotary table I'd bore holes for mounting bolt using the existing cam lock stud holes. Or would I be better off mounting the chuck on a plate I make with a 2 1/2" dia x 3" stud on the back that I can mount in the four jaw and dial into near 0 runout. With the 1/8 inch locking range and the ability to hold short pieces I thought this would be a great asset for model engine building. Now I clamp my four jaw off my Atlas into the three jaw on the Monarch for small work. Thanks Roger


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## rkepler (May 7, 2012)

It'd be fairly hard to make a D1-5 nose and D1-6 back. Is the Jacobs a model 91 collet chuck? It would be a lot easier to trade the D1-5 chuck for an existing D1-6, the latter being common and the former fairly uncommon.


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## kvom (May 7, 2012)

If you can find an inexpensive D1-6 dog driver or faceplate, then I see no reason not to try to make it an adapter plate as you describe.

In the past I've seen D1-6 rubberflex chucks selling for ~$250, so looking for one might be the best bet if you can't find a cheap adapter. Assuming D1-5 also uses 6 lugs, you'd might need to use 3 on the adapter and three on the chuck if hole spacing becomes an issue.


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## rebush (May 7, 2012)

Rkepler and kvom: Thanks for your replies. It is a model 91 collet chuck. It uses three lugs. My Monarch even thou it's a D1-6 only uses three lugs. Where would I post an offer to trade my chuck for a D1-6 chuck if I should decide to go that route? I've got some steel plate and rod stock kicking around I think I'll try making something up first. I'll post my results when done. Thanks. Roger


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## kvom (May 8, 2012)

Here's one for sale: http://classified.practicalmachinist.com/l/871/wts-D1-6-jacobs-spindle-nose-collet-chuck.html


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## rebush (May 8, 2012)

kvom: Thanks for the link. Just e-mailed the seller to see if it's still available. Roger


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## rebush (May 9, 2012)

kvom: E-mailed the seller it sold earlier in the day. If you happen across another one please let me know. I think for now I'll make a 5 3/4 dia. plate 1/2" thick and but a large stud on the back that I can mount in the four jaw. The plate will attach to the collet using the existing threaded holes for the D1-5 lugs. That'll get me by till I find one for sale and I've done no harm to the original in case I find a trade out there. Is there any difference in aligning a round stud vs a square stud in the four jaw? Thanks Roger


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## Rockabye74 (Jan 13, 2021)

I realize that this post is ancient, but I have just acquired a d1-5 Lathe and a D1-6 Jacobs Rubberflex Collet Chuck, are you still interested in a trade?


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## Richard Hed (Jan 14, 2021)

Rockabye74 said:


> I realize that this post is ancient, but I have just acquired a d1-5 Lathe and a D1-6 Jacobs Rubberflex Collet Chuck, are you still interested in a trade?


Do you have fotos?


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## Rockabye74 (Jan 14, 2021)

Pictures of the 91-C6 uploaded. I also have a 91-C3 that I would be willing to trade for a 91-C5.


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## Rockabye74 (Jan 14, 2021)

Pictures of the 91-C3. I am disassembling the C3 to clean it up and lube it. It was a little stiff. I will clean up the 91-C6 too, but I didn't want to risk mixing parts. Like I said I am willing to trade each/either of these for a 91-C5.


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## Richard Hed (Jan 14, 2021)

Rockabye74 said:


> Pictures of the 91-C6 uploaded. I also have a 91-C3 that I would be willing to trade for a 91-C5.


I have a 5-D1 system which has 6 holes.  I wonder if those three holes would be spaced correctly for 5 D.  It would be nice to have chucks like those


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## Rockabye74 (Jan 14, 2021)

The D1-5 and D1-6 systems have different radii and different diameters for the pins. In addition the center alignment bevel is a different radius. I have included a PDF that describes many of the chuck systems and shows their dimensions.


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## Richard Hed (Jan 14, 2021)

Rockabye74 said:


> The D1-5 and D1-6 systems have different radii and different diameters for the pins. In addition the center alignment bevel is a different radius. I have included a PDF that describes many of the chuck systems and shows their dimensions.


That's what I was afraid of.  Thanx, it was a good try


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