# Installing a DRO on  PM-272V



## The Bumble (Apr 20, 2018)

Hi all - 

I am a hobbyist and thinking about buy a bench-top mill. After looking around, I think I've settled on the Precision Matthews 727V. I wanted to buy it with the 3 axis DRO installed, but they are out of stock. If I were to buy the mill and the DRO separately, would a novice be able to install the DRO successfully? I'm handy, but.....


Thanks.


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## Eddyde (Apr 20, 2018)

Well if you are buying a mill, you are probably a bit more than average handy. So I would say yes, you can do it. It will be a great learning experience and you'll get all the help you need here.


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## Winegrower (Apr 20, 2018)

For me, the hard part was figuring out the exact placement of the scales.   Perhaps you could get some photos of an installed DRO of your model.


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## jmarkwolf (Apr 20, 2018)

Get on the DRO Pro's website, regardless of the DRO you plan to purchase, and check out the vast library of DRO installation photo's on users machines. It'll give you ideas. They also have "factory" videos. There may be installation pics and videos for your exact machine.

I just installed my DRO for the third time. First time was a bench top mill/drill 10 years ago, then transplanted it to an old Bridgeport 5 years ago, and I just transplanted it to my new ACER 3VS ii, buying longer scales each time. The scales for my DRO are magnetic so the installation is somewhat different than glass scales, etc.

I'm not familiar with your machine but I found a slick way to hold/adjust the scale for the x-axis that would've been useful on all 3 of my installations, so it may be useful on yours. Pic below. The slotted parts are easy to make, even without a DRO, and saves some frustration. Using 123 blocks, it allows adjusting the scale while you determine the best placement relative to your read head.

I would suggest mounting all your bracketry in the middle of it's travel. This allows adjustment/fudging later.

Take care to locate your holes correctly, and be mindful of the drill bit walking while hand drilling. Center punch, then center drill, then drill with a sharp bit can help. Be mindful of the drill angle when hand drilling, it's easy to get off perpendicular to your surface, and your hole may end up 0.050" from where you need it.  Don't drill any holes until you're absolutely certain where they need to be. Be careful, breaking drills and/or taps is a giant PITA!

Don't overlook the indicator and setups you'll need to make sure the scales are square and aligned properly. This is important.

Take your time, it is tedious and will take awhile. Don't rush it.

The parts below clamp to your bed, and capture the scale, making it easy to position the scales and play with the read head location and alignment before committing. Put one at each end of the scale.

The bolts are over-kill but that's what the 123 blocks are threaded for. They are just over finger tight, and the scales can be "bumped" where you need them..


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## Greebles (Apr 21, 2018)

Myself and several others here have installed DRO on their PM-727. It is not difficult if you take your time and plan it out first.

I have photos of my install available if you need ideas.

-Denzil


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## Balor (Apr 21, 2018)

Hi Greebles, yes I would like too see the pictures on your PM-727.

rngr1


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## Greebles (Apr 22, 2018)

PM-727 DRO Install

I mounted the Y scale along the front of the table using the existing track (for table stop). The X scale is mounted on the left hand side (facing the mill). I choose the left side to keep the scale out of the way from the table locks that are on the right.

You will need to make / modify brackets and spacers so be prepared to do that. Also be willing to make small adjustments to the mill itself. For instance I had to grind a spot flat along the side of the saddle to remove the rough casting surface for my mount to sit flush. (last photo)

When planning think about how everything will be once installed. Imagine scenarios of how you work and place the scales accordingly. For example the common approach is to put the X scale on the right but with the table locks there I decided to move the X scale to the left.

-Denzil


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## The Bumble (Apr 22, 2018)

Thanks for the replies all. I think I'm going to let the factory do the install and once I get the machine, I'll study it to get a better understanding of what is involved. As with many things that I have done in the past, mistakes taught me a lot. However, with this, don't want t learn that way.


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## jmarkwolf (Apr 22, 2018)

Be advised if you use the t-slots on the front of the table for the DRO you likely won't be able to use them later for the stops on a table feed.


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