# Anyone here add a DRO to a Bridgport?



## CMS (Nov 24, 2009)

Would like to add a DRO to my old Bridgeport, and would like to know what others are using and where it was purchased. The table on mine is 9"x32" and I think a x/y axis unit will be all I'll be looking for.


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## hammers-n-nails (Nov 24, 2009)

i have dro's that came on the two chinese bridgeport clones, they are from grizzly and i dont have any complaints other than that the manual is in chinglish and isnt too good even if you can read it so i cant figure out how to do an x/z ory/z arc, but ive never used any other brands. i assume they all have arc, angle, circle of holes and all the rest but if not i would reccomend getting one that does, i use these features all the time, espescialy arc, it may not be so useful in a shop but for modeling it is great. i would also reccomend getting all 3 axis, if the cost difference isnt too much.


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## ksouers (Nov 24, 2009)

CMS,
Not a Bridgeport but I installed a 3-axis DRO on my Burke knee mill. I got the DRO from Shars Tool Company in Chicago.

http://www.shars.com/product_categories/view/40602/Digital_Readouts

It's Chinese but it's glass scales and works very well. Lots of common procedures already programmed into it; bolt circle, bolt line, arc etc.

Here are some pics of the install...

Display:






Scales:


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## CMS (Nov 25, 2009)

Thanks for the input guys, but the responces only arouse another question. What is the bolt circle, bolt line, arc, angle terminology? I think I might know what these are, but as you might can tell, I'm still doing my homework on the DRO bit. Anything past the standard X, Y, and Z readings and it's new to me.
 One thing I've noticed is the location of the scales. Is there any pro's and con's to mounting the X axis scale to the front or the rear?


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## cobra428 (Nov 25, 2009)

CMS,
Bolt Circle is....You punch in how many holes you would like and on what radius. The DRO will start at 0 deg. to how ever you have it set up. From X or from Y. You can offset the angle so you start at some angle to 0 deg.
 Bolt line you can start at an edge move in say 1/2" go to INC now you start the count from there. You can also do an x/y bolt pattern and tool change if the DRO has that capability.
 It's a great tool once you learn how to use it. I put a scale (modified digital caliper) on the quill to get a cheap mans Z axis till I bought a 3 axis and move the 2 axis to the lathe.

I have a power feed on my x so the scale in the front will get in the way of that. I put mine in the back....I loose a little distance of motion but it never gave me a problem. Now that I said that.....tonight I'll run into it :big:

Hope this helps

Tony

PS I have a Harbour Frieght 8 x 22 mill and a Shooting Star DRO


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## chip_monk (Nov 25, 2009)

Hi, 

I have a Sino DRO on my Raglan mill bought from Jade products over the web, works very well. There is a very good reason not to put the X scale on the rear of the table on my little mill, it reduces the Y travel by the width of the scale. May not be so much of a problem on a Bridgeport. 

David


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## hammers-n-nails (Nov 25, 2009)

in arc function you program center point, start/end points, radius, tool diameter, step size and inside or outside radius and it will give youa a series of points. starting with the first you move until the DRO says X-0.0000 Y-0.0000 push the down button and repeat. i used this function extensively on this engine http://www.homemodelenginemachinist.com/index.php?topic=6503.0 the crank, beam, and parallel link pillow blocks, the outside of the parallel links themselves, sides and little end of the connecting rod, outsides of eccentric strap, and some other parts pretty much everything that isnt completly round was made using this function its 10 times easier and faster than trying to get it lined up on the rotary table as long as it doesnt have to be absolutly perfect like a hole for a shaft or something. i would be lot without it. in angle you just tell it what angle and do pretty much the same thing. one axis stays straight with the table and the other is rotated, its hard to explain but easy to do. sorry for the long-winded reply.

zach


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## stevehuckss396 (Nov 25, 2009)

CMS  said:
			
		

> Would like to add a DRO to my old Bridgeport, and would like to know what others are using and where it was purchased. The table on mine is 9"x32" and I think a x/y axis unit will be all I'll be looking for.




KBC tool had a 2 axis kit for sale that was Mitutoyo. It was a 12X30 that fit my table. I bought 2 kits and did X, Y ,Knee, spindle. A single kit was $660 but 2 was much cheaper. They are brand new in the box with all the mounting hardware and cost $1600 last year. They were cheap because they are last years model and the new stuff was coming in. They may still have a kit or 2 at the sterling heights MI store.


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## kvom (Nov 26, 2009)

I bought my BP with the DRO already attached. X-scale is on the back, and Y-scale is on the right. I don't have a Z-scale as all precision Z-axis positioning is done with the knee dial and/or a quill stop.

While my DRO has a bolt circle routine (in theory), it seems to not be working properly. However, I generally find it just as easy to compute X-Y positions myself.

The DRO functions that I use all the time are the "1/2", for centering, and the ABS/INCR for holding two sets of coordinates. I typically set the ABS zero to a vise stop or rotab center, and use the INCR coords for everything else.


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## duckman (Nov 26, 2009)

Just looked at CDCO web site they have DRO's with glass scales , little more than $400.00


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## shred (Nov 27, 2009)

I have a Jenix DRO on my Millrite and I like it a lot. Tons of features and amazingly accurate. IIRC they're about $700 complete for 2-axis and $800 for 3. 

Bridgeports are so popular you should be able to get a kit with all the scales and brackets and such pretty easily from most of the DRO shops.


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## CMS (Nov 27, 2009)

Thanks for all the input. I talked with a fella that sells Newall, Acu-Rite, etc. and finding out that the length of the scale that's required vs. the length of travel is different between the glass and the linear encoder. He was telling me that the glass scale would be about 10" longer than the travel, and the linear encoder was about 6" longer than measured travel. 
 So with the stubby 32" total length table that I have and the maybe 18" of travel, it's going to require something less than standard, I guess. ??? The other thing that's going to be a dilemma is wheather to save and go with the "Made In USA", or bow down and go with the much less pricey import.


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## kuhncw (Nov 27, 2009)

I've had a Newall on my Supermax mill (X an Y axis) for probably 13 years or so. It was easy to install and has always worked fine. 

Regards,

Chuck


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## rcplanebuilder (Nov 29, 2009)

I've had no complaints with the 3 axis Grizzly. Good bang for the buck. 

As stated by others, circle pattern features, and the like, get used here all the time too. 

The halving feature for finding center, and having an on board calculator, earn their keep too. 

I'm with the "all 3 axis" votes. Though admittedly, for some reason, the Z was the biggest hassle to mount up on mine. 

FWIW, If you are doing repeated depth cuts, such as on a rotary table, the clear plastic cover works great with a grease pencil to write your numbers on, above the axis you are watching. Smear them off with your finger, and re-pencil it in for the next one.


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## CMS (Dec 4, 2009)

Well I just ordered a DRO from DRO-PRO. I bought the "house brand" in the 3 axis flavor. Todd, the salesman, was very helpfull and went above and beyond to answer my questions I had and the even the questions that I didn't know that I had. Now I would state that it needs to hurry-up and get here, BUT, it's to be a Christmas present from the wife so no playing with it till then. Maybe she'll at least let me watch the video that comes with it so as I'll have a heads-up on the working my new toy. I have bought a new-to-me vise, it's a Kurt 688 with a swivel base, man is that thing ever sweet.


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## Pull Up Now! (Dec 25, 2009)

ksouers  said:
			
		

> CMS,
> Not a Bridgeport but I installed a 3-axis DRO on my Burke knee mill. I got the DRO from Shars Tool Company in Chicago.
> 
> http://www.shars.com/product_categories/view/40602/Digital_Readouts
> ...




I am installing a Sino from Shars. Question, the readers are surrounded with red plastic slide guides. Are these for shipping only? Or do they stay on the DRO scales all the time? Thanks!


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## Cedge (Dec 25, 2009)

Shipping purposes.... although they came in quite handy as spacers while installing the scales. 

Steve


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## Pull Up Now! (Dec 26, 2009)

OK, thanks for the info. The spacers do seem to position the reader portion pretty close to the final dimension given, which is a total distance from the bottom of the reader to the top of the glass scale housing. It's around 62mm if memory serves correctly. The actual was more like 63mm. A delta of around .039 inches.


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## Blogwitch (Dec 26, 2009)

If this is any use to you, this is how and where I fitted my Z axis DRO onto my 836, which is slightly smaller that the Bridgport, but should still be relevant.

http://www.homemodelenginemachinist.com/index.php?topic=2314.msg23273#msg23273

Using this method, the glass scale is moved and the read head is stationary, you could easily do it the other way around, as you won't have to worry about the control bar for the Z axis power feed, because you don't have one.

I personally would fit the X axis head behind the table, it is out of the way there and won't interfere with your table stops. Mine has a physical stop bolted onto the way to stop the read head being crushed against the main mill column. It stops the table going any further back and leaves about 1/16th gap between the column and read head.
You do lose a very small amount of movement in the Y axis by mounting it at the rear, but you need to remember, you have your main head ram that you can move in or out if you need some extra cutting length. Up to now, I haven't had to resort to that operation.

I have been using the same Sino units on both the mill and my lathe for over a year now, with a total of 7 read heads and 3 display heads, and except for a silly mistake by myself on fitting (now rectified).

http://madmodder.net/index.php?topic=1938.0

They haven't missed a beat.


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## CMS (Dec 26, 2009)

Santa brought my dro from DROPRO and I've got the x and y axis done will try for the z axis today. I mounted the x scale to the rear of the table, but there was some extra cost in doing this as the drill motors I had were too big to fit between the rear of the table and the main body. So off to Lowes for a right angle drill, on Christmas eve at 5:00 pm. I did overlook one thing, when I mounted the scale for the y axis I don't think I left myself enough room for mounting the chip guard. Anyway, I'll post some pictures when I finish the install.


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## d-m (Dec 26, 2009)

I used DRO PROS when I was looking, I was pleased shipping and support was top notch. For weeks after I seemed to have a hard time, I was allways double checking the dro with the hand crank LOL.
Have fun, and happy new year!!
Dave


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## CMS (Dec 26, 2009)

With the exception of cleaning up the wiring, I hope the install is complete. The only forwarning I could give to anyone is all the hardware is metric. The kit came with ample amounts of 5mm & 6mm cap screws washers and nuts, 4mm hardware was just right, but the 3mm selection was short. But fortunate for me, I have a good selection of metric nuts bolts and washers. I don't really like the way the trolley bracket worked out for the Z axis, but I was bound to try to install everything with what was supplied in the kit. Will more than likely make a more eye appealing bracket in the future. There also wasn't any way of mounting the chip cover on the Z axis ether. I messed up on the Y axis by not mounting the scale low enough, but for the most part it's covered by the tablr anyway, so I think it will be ok.


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## JimM (Dec 26, 2009)

I'm also looking at fitting DRO's - got a quick question on scale sizing though. If the table is 28" wide with a travel of 18" what size scale would I need ?

Thanks

Jim


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## CMS (Dec 26, 2009)

My table is 32" with maybe 20" travel. A touch short because of the old power feed, but anyway, the scale I used was 600mm long and I could have went longer with out extending past the table but the extra length would've been useless. The guy I dealt with, Tom, was very helpfull and knolageable. Go to the DROPRO websight, there's lots of videos and pictures on useage and installations.


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## Blogwitch (Feb 4, 2010)

There is nothing wrong with your Z axis setup, but I personally would be a little worried over the cable run to the read head. Especially since you couldn't get the protective cover to fit.

The spiral cable form is renowned for letting liquids run along them, and in your setup, any loose liquid would run straight down the cable and sit on the end of the read head. They are not waterproof, just resistant.

I mentioned it here, to explain the problem.

http://www.homemodelenginemachinist.com/index.php?topic=2314.msg23293#msg23293

With a little care, it is relatively easy to disassemble the read head and put the cable to exit from the other end. I have had to do it on a couple of my read heads, and they are still working OK (now asking for trouble).


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