# Another "What Is It?" Bridgeport Accessory?



## Ironside (Mar 8, 2018)

I got this in a mixed lot of Bridgeport stuff. It's about 16" long overall. The bore is pretty much the exact size as a Bridgeport J Head spindle. The mechanism attached to the bracket can slide and lock at any point in the slot. As you rotate the knurled part the shaft extends or retracts. I  
	

		
			
		

		
	






	

		
			
		

		
	
 Thanks in advance for any input.


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## BROCKWOOD (Mar 8, 2018)

I'd use it to zero in the head after angular usage. Looks like a fun thing to make for my mill!


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## benmychree (Mar 8, 2018)

I had a similar device for a Bridgeport "M" head, it is a tracer to do 3 dimensional work; the adjustable tracer finger rubs against a positive and the ball end mill cuts the same form in the workpiece.


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## cg285 (Mar 8, 2018)

i'd like to see that in action. looks like it would take 3 hands

trace piece looks similar to an automotive boring bar mic


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## benmychree (Mar 8, 2018)

All it took was downward pressure on the spindle, follow a line of cut, step over, repeat.  On the one that I had, the center distance between the spindle housing and the follower was adjustable, I don't think it was more than about 10" or 12" long overall.


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## benmychree (Mar 8, 2018)

The trace piece would be the same radius as the ball end mill being used; on mine, the tracer was removable so different sizes could be used.


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## Silverbullet (Mar 8, 2018)

It's the stylus for tracing on a mill or router tracer machine. It would have a special free float air or hydraulic table or head.


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## chips&more (Mar 8, 2018)

Yes, I have I one those. Bridgeport called it a “Profiling Attachment”. They had two versions. Part #PM-1 was for the M head. And Part #PJ-1 was for the J head. And sorry or hopefully you have the spring attachment that goes with yours?


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## Ironside (Mar 8, 2018)

Thanks, you guys are awesome. It makes sense now. You can see where it is able to accept different type profile tips. And nope, this is the only part that I have. I can look through the box of stuff that came with the lot, but I don't remember seeing a spring attachment.


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## benmychree (Mar 8, 2018)

chips&more said:


> Yes, I have I one those. Bridgeport called it a “Profiling Attachment”. They had two versions. Part #PM-1 was for the M head. And Part #PJ-1 was for the J head. And sorry or hopefully you have the spring attachment that goes with yours?
> View attachment 261170


I remember now, that the spring part of the attachment was mounted on the bolts that the head swiveled on.


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## skrewd (Feb 23, 2020)

Old thread but I need that other part. The pj-1 mounts to the other side. I have only seen front view images of it which hide or do not include a spring. Can anyone post images of it from other angles?


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## skrewd (Feb 23, 2020)

Is the spring hidden behind?


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## skrewd (Feb 23, 2020)

My best guess is the lower portion is adjustable and locking via a slit and bolt about 1.500 tall. The protruding guide rod is 8.000 long x 0.500 thick with a spring and a retaining clip at the top. This is in comparison to the m style.


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## petertha (Mar 5, 2020)

That's cool. Dumb question but why the (what looks like) stabilizing arm off to the side? Would there be that much rotational play in a typical spindle or maybe allow the assembly to maintain the same lateral position like if you had to adjust it or remove it?


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## skrewd (Mar 5, 2020)

My best guess from what I see is it has two functions.  One an added spindle lock, to maintain z height thru an x and y plane. Two extra spindle upward return to prevent sag or droop with the added weight.


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## Alcap (Mar 5, 2020)

It would interesting to hear and see things made with that tracer attachment . I've seen those for router for years but never manual one for a milling machine


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