# Draw bar too long?



## monkeyb0y (Apr 15, 2014)

Ok stupid question. I just wired up my Bridgeport 2hp Varispeed and when I put an R8 collet in it to tram the head the collet wouldn't draw up tight. It stuck out from the quill about 1/4 inch. The draw bar came with the mill but did they give me the wrong one or am I doing something stupid. The draw bar measures 22.5 in overall with a 4 in nut then a 0.25 in "washer"/spacer and a 18.25 in shaft the last inch being threaded. I'm new to all this and have been reading all I can but have little practical experience so I could easily be overlooking something so basic no one mentions it.  

Thanks
Kevin


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## schor (Apr 15, 2014)

Your probably right that its too long but you would think that things would be pretty standard on an r8 setup. You could just shorten the drawbar you have.

I made a new drawbar for my mill and did intentionally make it longer than the orig so I would have something to play with if/when I stripped threads. I made mine out of solid stock but usually there is a head and bar connected with a roll pin, you could make a shorter bar, keep the head and orig bar in case you find some r8 holders that need your longer bar.

A vid of the making of my drawbar if your interested.

[video=youtube_share;mmaqK4VtulY]http://youtu.be/mmaqK4VtulY[/video]


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## davidh (Apr 16, 2014)

I ended up adding spacers under the head of the nut until I was satisfied it was correct.  I don't understand how the prior owner used it the way I got it.  wobble like crazy. . .


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## chips&more (Apr 16, 2014)

Hi, it sounds more like you are missing a stepped washer and not a wrong draw bar (DB). There should be a stepped washer right below the DB hex. This washer locates in the top end hole of the quill and centers the DB at its 3/8" shaft and the hole. If you turned the head 180° for any reason with the DB out, this washer we are talking about probably feel out and got lost. And about shorting a DB. If you have a well made one the threads should be rolled instead of just cut. The rolled threads are the best thing to have and I would not go and modify the threads in any way. I would shorten elsewhere…Good Luck.


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## monkeyb0y (Apr 16, 2014)

Thanks for all the input. I will probably try turning a spacer to put on the shaft. If that doesn't work I'll just get a new drawbar. At least the cause of the problem wasn't me!


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## Ray C (Apr 16, 2014)

Hey guys, I always use a double nut mechanism on my drawbars...  This can save your bacon if you ever get a situation whereby the DB gets hopelessly tight against the top of the spindle.  Using this method, you always have a way to loosen it.  You'll also notice I have a small spacer.  It helps keep the DB from wobbling (even though that doesn't seem to impact anything) but also limits the amount of engagement into the R8 device to a sane level.  I screw it in about 1" which is about 2.5 times the diameter of the bar -plenty of engagement...

Ray


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## furpo (Apr 16, 2014)

monkeyb0y said:


> Thanks for all the input. I will probably try turning a spacer to put on the shaft. If that doesn't work I'll just get a new drawbar. At least the cause of the problem wasn't me!
> 
> 
> Sent from my iPad using Tapatalk



Draw bar 
http://www.mcmaster.com/#milling-machine-drawbars/=rkh6n6


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