Questions about new DRO

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Mr Ron
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Location: Vancleave, Mississippi

Questions about new DRO

Post by Mr Ron » Sat Jul 07, 2018 3:26 pm

I'm trying to gather as much information about how best to add my future DRO to my mill. The DRO is expected to arrive on the 10th, but it will probably be on the 11th that I will start fitting it to the mill. My 1st question is; can I fit the X-axis scale to the front of the table instead of the back? I suspect there are side forces at work, either when drilling or milling which would cause the table to move. That movement would be controlled by locking the X-axis before cutting or drilling. That same goes for the Y-axis; am I correct? If so, that would eliminate fitting the scale to the front of the table because that is where the table locks are located. I would appreciate any advise you may have to help me fit this DRO. I will probably have a few more questions before the task is complete. Thank you.
Mr.Ron from South Mississippi

Jaxian
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Re: Questions about new DRO

Post by Jaxian » Sat Jul 07, 2018 3:47 pm

My own experiences with DRO installation is that you should ignore the installation kit unless it is specifically made for your machine (and they never are) and just put it where it can meet all your needs. This means making custom brackets. This isn't hard but it can be time consuming.

The first thing I do is trial fit the scales on the machine until I find the spot they will do their job the best. Then build brackets to make that work. For best function you could look at the RobRenz video on YouTube where he talks about mounting the readers directly under the screws. Then when you realize there is no way you can actually pull that off and that level of accuracy isn't necessary just install them where they work.

I don't use DROPros, they are a little too expensive for my liking and not made well enough so the glass scale ones I have are more fussy to mount but the same basic thoughts should work for you. I will attach some picture. Bear in mind I made these brackets years ago when I had only been machining for a few months so they aren't very pretty or complex. I always said I would go back and make them nicely but they work perfectly so I have never messed with them.

https://www.youtube.com/watch?v=LCesEzS4jbI

Z axis knee:
IMG_20130423_190625_487.jpg
Y axis:
IMG_20130508_021301_239.jpg
IMG_20130508_022600_721.jpg
Whole machine, looks like I never took a close up of the X axis:
IMG_20130702_225001_392.jpg
Last edited by Jaxian on Sat Jul 07, 2018 4:12 pm, edited 1 time in total.

fenichel
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Location: West Vancouver, BC

Re: Questions about new DRO

Post by fenichel » Sat Jul 07, 2018 4:10 pm

I agree with Jaxian as regards non-mill-specific DRO mounting hardware, but not as regards DRO Pros ("DP").

I used to own a Sieg SX3 mill, and I mounted one of DP's' 3-axis glass-scale kits to it. My main lessons learned were
  • DP is a pleasure to deal with, and I thought that the DRO and scales they supplied were well made;
  • Notwithstanding that, the collection of aluminum angles that DP supplies as mounting hardware was next to useless. The angles had predrilled holes and premilled pockets that kept them from being usable with that mill; and
  • The glass-scale DRO was more than satisfactory, but I probably should have sprung for the magnetic-scale kit instead of the glass-scale one.
For what it's worth, a description of my mounting of the Z-axis scale is on my Web site at http://www.fenichel.net/pages/Indoor_Ac ... %20DRO.doc.

Jaxian
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Re: Questions about new DRO

Post by Jaxian » Sat Jul 07, 2018 4:18 pm

I am not arguing that DROPros are bad. They are really nice to deal with and their stuff works well. But they are not built to the level of other units and the Jenix ones I use are both cheaper, (I think the 4 axis setup you see on my machine was $695 complete), and made better. Armored cables, cast aluminum housings. Cable ends are screw on mil-spec type metal. I had also heard from a DRO re-builder that DROPros head units are filled with whatever is cheapest at that time. Makes them a total pain to repair and inconsistent in their reliability long term. Strictly his observation not mine, but he does do this for a living.

I just picked up a 2 axis for my small lathe with the .00005" X axis scale for $595 with tax, delivered about 4 months ago. So still inexpensive.
20180414_175342.jpg

John Evans
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Re: Questions about new DRO

Post by John Evans » Sat Jul 07, 2018 5:52 pm

Do NOT disable the table locks !! You will need them,mount to the back side of the table. Remember the rule -lock all axis except the one in use.
www.chaski.com

Mr Ron
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Location: Vancleave, Mississippi

Re: Questions about new DRO

Post by Mr Ron » Sat Jul 07, 2018 10:23 pm

John Evans wrote:
Sat Jul 07, 2018 5:52 pm
Do NOT disable the table locks !! You will need them,mount to the back side of the table. Remember the rule -lock all axis except the one in use.
Thanks. That is exactly what I needed to know. I just wanted to work at the front because it is easier to access. The lock for the Y-axis is on the left, so I will have to fit the DRO to the right side. Since I'm 83 going on 90, I look for the easy way to do things.
Mr.Ron from South Mississippi

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NP317
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Location: Northern Oregon

Re: Questions about new DRO

Post by NP317 » Sun Jul 08, 2018 12:18 am

I installed the DroPros 4-axis kit on my mill. Great success.
I mostly used the included mounting brackets, mixing, matching, and modifying as needed to achieve my goals.
Here are some pics of the X and Y installations for your entertainment.

X-scale mount on rear of the table:
Mill X-Axis1 small.jpg
X-scale mounted and covered. Note the brass hex piece to protect the scale from hitting the column.
Simple solution, because I have no Y-power feed. Hand feed only.
Mill X-Axis2 small.jpg
I later moved the stop piece under the scale, so it was easier to clean the top of the scale cover.
Mill X-Axis3 small.jpg
Y-scale mount under the right side of the table.
Mill Y-Axis1 small.jpg
Y-scale protection cover installed.
Mill Y-Axis2 small.jpg
If you need pictures of the quill and/or Z axis installations, I can provide those too.
'Hope these help some.
~RN

Mr Ron
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Re: Questions about new DRO

Post by Mr Ron » Sun Jul 08, 2018 2:18 pm

NP317 wrote:
Sun Jul 08, 2018 12:18 am
I installed the DroPros 4-axis kit on my mill. Great success.
I mostly used the included mounting brackets, mixing, matching, and modifying as needed to achieve my goals.

~RN
Thanks for the pictures. They will be a great help. I was just looking at my mill and wondering about mounting the scales. Your pictures answered a lot for me. I especially like the brass pin to protect the encoder from hitting the column; something I wouldn't have thought of. Oh! one question; mounting the X-axis encoder to the back of the saddle; is there enough room between the saddle and the column to drill holes for mounting the encoder?
Mr.Ron from South Mississippi

pete
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Re: Questions about new DRO

Post by pete » Sun Jul 08, 2018 2:38 pm

Fwiw some years ago I saw one of the best and well thought out DRO installations on one of the machinist forums for a Bridgeport type mill but can't recall where it was. The poster did mount his X axis on the front of the table, managed to keep the table locks and power feed adjustable limit stops. He also used at least 2" x 2" heavy steel angle iron as protection above the X axis scale since mounted on the front I think it's quite vulnerable to heavy items such as mill vises, rotary tables or large heavy parts being dropped on it.

Even better ROBRENZE on Youtube is an extremely talented, more than clever and over the top professional machinist who mounted his X axis scale and reader head under and inside his mills hollow table casting. A lot more work to do it that way of course, but it doesn't lose any Y axis travel or complicate maintaining those table locks and power feed stops. Plus the scale stays cleaner and would be really well protected. It's the first time I've ever seen any X axis scale mounted that way. I'm 2-6 months away from investigating if it's possible to do the same on my mill. I expect to pull the table at least a few times while getting the scale and reader head mounted and properly aligned if it is possible to do it, but think it would be well worth the extra work.

Mr Ron
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Re: Questions about new DRO

Post by Mr Ron » Sun Jul 08, 2018 4:47 pm

pete wrote:
Sun Jul 08, 2018 2:38 pm
Fwiw some years ago I saw one of the best and well thought out DRO installations on one of the machinist forums for a Bridgeport type mill but can't recall where it was. The poster did mount his X axis on the front of the table, managed to keep the table locks and power feed adjustable limit stops. He also used at least 2" x 2" heavy steel angle iron as protection above the X axis scale since mounted on the front I think it's quite vulnerable to heavy items such as mill vises, rotary tables or large heavy parts being dropped on it.

Even better ROBRENZE on Youtube is an extremely talented, more than clever and over the top professional machinist who mounted his X axis scale and reader head under and inside his mills hollow table casting. A lot more work to do it that way of course, but it doesn't lose any Y axis travel or complicate maintaining those table locks and power feed stops. Plus the scale stays cleaner and would be really well protected. It's the first time I've ever seen any X axis scale mounted that way. I'm 2-6 months away from investigating if it's possible to do the same on my mill. I expect to pull the table at least a few times while getting the scale and reader head mounted and properly aligned if it is possible to do it, but think it would be well worth the extra work.
I don't think I'm up to taking my mill apart, but thanks anyway. The more tips I get, the easier it will be to do my installation correctly and easily. Many times we go charging ahead and end up screwing it up. I appreciate all the information I get from you guys. I'm sure my installation will now go more smoothly. I will be the first to admit, I don't know everything and can always learn something new.
Mr.Ron from South Mississippi

pete
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Re: Questions about new DRO

Post by pete » Sun Jul 08, 2018 5:38 pm

I think I'm the same and always like getting as much information as possible on something as critical as installing a DRO Ron.

From what I've seen and did with my mill after getting it I highly recommend at least pulling the table with any new or used mill. I'd certainly do so even with a brand new Bridgeport if I could afford one. Removing all the preservitive coatings, readjusting the gibs and feed nuts on new machines and cleaning out all the chips and wear particles on a used mill and doing the same adjustments is more than worth it. The whole machine works much smoother, it's tighter and more accurate, and the critical wear and alignment surfaces will last multiple times longer. I pull the table and Y axis about once a year and at most it now takes about 2 hrs to do the job and it's not a complicated process on any mill that doesn't have built in power table feeds. While I didn't find all that much grinding dust or ground metal dust in my Taiwan built mill there was certainly enough I'm very happy I did do it. I also like verifying the one shot is pushing oil everywhere it should since it's not uncommon for a few oil ports or lines to get plugged up and quit working. I should soon start beefing up and reworking my whole floor in my shop so the complete mill has to come apart to move it out of the shop anyway. :-( Luckily I now have an engine hoist that I didn't have when I bought the mill and had to do it back then with human power and Egyptian Pyramid building strategy. With a knee mill it's easy to use that knee for elevation and set a temporary stucture up and just slide the table off onto it. I use a couple of hold down bolts in the tables tee slots to lock down a few pieces of wood 2" x 4" to use as handles.

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NP317
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Location: Northern Oregon

Re: Questions about new DRO

Post by NP317 » Sun Jul 08, 2018 7:07 pm

Mr Ron wrote:
Sun Jul 08, 2018 2:18 pm
[snip] Is there enough room between the saddle and the column to drill holes for mounting the encoder?
With the table moved fully to the Y-front I had plenty of room for drilling mounting holes between the column and the rear of the table.
I also have a 90 degree drill, but I don't remember if I needed to use it.
~RN

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