# JMD-18 (RF-30/RF-31) Upgrades



## flexjyork (Sep 9, 2020)

New to the forum within the past few months after recently purchasing a JMD-18. I'm quite impressed with this forum's demeanor, knowledge/skill set, and overall willingness to share information (in comparison to some other forums) so I figured I'd share my project here.

I've wanted a benchtop mill for the past few years to support my off-roading hobby and other small projects, but never pulled the trigger on purchasing one due to limited garage space. Additionally, I always seemed to make due with the tools I have. But then there was an estate sale of a "friend of friend...", so I purchased an WMC (rebranded JET JMD-18). The mill was practically in brand new condition, used for a couple wood working jobs, as it still had the corrosion resistant grease on the column most other surfaces. It also came with some HSS end mills that were brand new and the original vise (which has already been replaced).








So on to the machine upgrades. After researching a few modifications and determining that a CNC upgrade would be nice, but not practical for my needs, I decided my first few upgrades would be a power feed for the X-axis and a 3-axis Digital Readout DRO.
I purchased the power feed from MSC as it's just a rebranded version of the Align AL-500P and the best price I could since they offer coupons. The power feed was pretty straight forward as an installation. I opted to install the limiting switch, which does reduce X-axis travel, but it's not a concern for me at the moment. When installing the drive gear on the X-axis Table Lead Screw, I did spot drill the lead screw surface, where the set screw would, and applied blue loctite. Additionally, I ensured there is some backlash throughout the entire rotation. I didn't measure it, just did it by feel. It's been working great the past few weeks.






As for the DRO, many thanks to @DavidR8 and @Gravydog for their informational DRO posts as it gave me some great information on what to buy and ideas on how to mount my scales.

I decided to purchase the AliExpress YIHAO YH800-3 and opted for the Slim scales with 1um. The additional cost for the slightly smaller scales and the more finite resolution was worth the extra IMHO. After several measurements and re-measurements, I ordered 150mm for the Z-axis, 200mm for Y-Axis, and 600mm for the X-Axis. After installation, I don't think I would have changed any of the lengths.

Each one has approximately 1/2 to 1" of travel remaining at each end of the mill capacities with the X-Axis power feed. I used some 1/4" and 1/8" angle for the Z-axis and some 1"x1/4" aluminum for the X and Y-axis to provide a mounting surfaces.

Some key notes for those that are considering this upgrade:
- I found the mounting brackets with the kit useless. They didn't align well with any of the scales mounting provisions. Get some bar and angle stock that your can modify for how you want to mount your scales.
- Mounting the X-axis scale behind the table does reduce Y-axis travel. You will have to be cleaver with kit in how you create a hard stop as not to damage the scales. I used a long SHCS with two jam nuts to hold the chip guard and double as a Y-axis travel stop.
- Before mounting any scales, connect each axis and test the system. Although I didn't have issues with mine, it always a good idea to test before installing.
- Buy some extra SHCS in 4mm and 5mm various lengths from 10mm to 30mm. This could have saved me about 4 additional trips to the hardware store.




































Overall I'm impressed with the kit and would purchase again. Hopefully this thread will be helpful for those that want to add a DRO to their mills in the future.

Next up the no-fog lubrication and possibly an led halo light. Thanks for reading.


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## macardoso (Sep 9, 2020)

Welcome to the forum!

I completely agree with your sentiment about this forum. I am members of many others, but this is the only one I consistently participate in. With only a couple exceptions, everyone on here has been absolutely wonderful to converse with.

I too purchased the same DRO you have for my lathe. I have been very happy with it.

Looking forward to seeing what projects you will use this for.

-Mike

PS: Cute pup


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## flexjyork (Sep 9, 2020)

Thanks for the feedback Mike. I'll be sure to continue to share my upgrades with this forum.


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## DavidR8 (Sep 9, 2020)

Welcome and thanks for the kind words. 
I can only give thanks to @Gravydog as he was the inspiration behind my install. 
Good job on your install, looks very tidy!


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## flexjyork (Sep 12, 2020)

Added a 12v power supply cabinet, small CCTV 5amp panel, to power the tachometer and halo light. That has added much needed lighting for my work area. Just used some small magnets epoxied to the light.
Pretty cheap mods considering the panel, tach, enclosure for the tach display, and the halo light (2 pack) were all together about $65.
Although I don’t have a VFD yet, I figured the tach mod would be useful until then (at least look cool)... any feedback on best place to find a 3 phase motor and preference on VFD.


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## DavidR8 (Sep 12, 2020)

I had no idea what I was doing with my 3-phase conversion. I found a video series by Clough42 in which he walks through a 3-phase conversion on his lathe. 
Because I’m clueless with electric motors I pretty much copied what he did except for going bigger on the motor to compensate for power loss at lower rpms. 
I went with 1.5 hp and a Teco VFD 


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## flexjyork (Sep 15, 2020)

@DavidR8 - For your motor frame size, did you use a 145T? If so, did you need to modify the motor mounting bracket or your pulley ID?


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## DavidR8 (Sep 15, 2020)

@flexjyork yes a 145 frame motor fit the mount perfectly. 

I did have to make a bushing to adapt the pulley to the shaft. I used aluminum because it was easy to cut the groove for the key in the soft metal vs steel. 


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## gonzo (Sep 20, 2020)

I must be brain dead. I have tried to order one of these dros but have been unable to negotiate the web site. Seems I can order one scale OR one readout but not one readout AND three scales. Additionally it seems that I can not get past the site security in order to purchase anything.
How frustrating!


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## flexjyork (Sep 21, 2020)

gonzo said:


> I must be brain dead. I have tried to order one of these dros but have been unable to negotiate the web site. Seems I can order one scale OR one readout but not one readout AND three scales. Additionally it seems that I can not get past the site security in order to purchase anything.
> How frustrating!



In order to purchase the 3 scale kit, you have to select the appropriate ship location (If in the US, you need to pick ships from China), then select the kit you want kit below. The title of the product will tell you if you selected the 3 scale kit. Good luck on the security issue. Might have to call your bank or CC to allow the purchase. 














						223.56US $ 8% OFF|Complete 3 Axis Dro Kit Set Big LCD Display Digital Readout Controller with 3pcs 5U Linear Scale Linear Optical Ruler 50 to 1000|Level Measuring Instruments|   - AliExpress
					

Smarter Shopping, Better Living!  Aliexpress.com




					www.aliexpress.com


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## gonzo (Sep 22, 2020)

flexjyork said:


> In order to purchase the 3 scale kit, you have to select the appropriate ship location (If in the US, you need to pick ships from China), then select the kit you want kit below. The title of the product will tell you if you selected the 3 scale kit. Good luck on the security issue. Might have to call your bank or CC to allow the purchase.
> 
> View attachment 337808
> 
> ...


Ok, I got all the way to the checkout finally. Now the only problem is there seems not to be any place to enter the length of scales that I need. I have see where someone said you only enter these lengths after ordering but I am loath to hit the pay part until I enter all my info. Anyone have more info?


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## DavidR8 (Sep 22, 2020)

gonzo said:


> Ok, I got all the way to the checkout finally. Now the only problem is there seems not to be any place to enter the length of scales that I need. I have see where someone said you only enter these lengths after ordering but I am loath to hit the pay part until I enter all my info. Anyone have more info?


If I recall correctly they contact you to get measurements.


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## flexjyork (Sep 23, 2020)

gonzo said:


> Ok, I got all the way to the checkout finally. Now the only problem is there seems not to be any place to enter the length of scales that I need. I have see where someone said you only enter these lengths after ordering but I am loath to hit the pay part until I enter all my info. Anyone have more info?



When you select "buy from from this seller" the next page allows you to leave a message. Add your lengths, scale sizes (normal or slim) and scale resolution to the text box. I ordered the slim scales and the 1um resolution (about $50USD more), so my message contained the following:

_YH800-3 Big LCD DRO Slim Scales (20mmx29mm) 1u Resolution 150mm (length) 200mm (length) 600mm Please provide updated cost for slim scales and 1u resolution prior to processing order. _

Once you submit, you will still have a chance to confirm with the seller the details before paying.


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## geoffm (Sep 25, 2020)

Remember to check your overall length vs travel. 145mm different if I recall on mine. Be very clear what  you are referring to. 
Love my DRO on my RF30, and the VFD is well worthwhile.  I haven't changed belt speeds since I put it on


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## gonzo (Sep 25, 2020)

I finally got mine ordered but what a WEIRD way to make a web site.


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## gonzo (Oct 23, 2020)

I am installing my dro unit now and am having problems with the mounting holes on the back of the pick ups. It seems that some  of the holes will not accept the screws as supplied due to fouling. I have purchased a 4mm tap, but apparently it is of the wrong pitch and will not work. Have any of you Chinese dro users have had that problem and know what kind of tap works?


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## flexjyork (Oct 26, 2020)

I don't recall having any issues with the hardware or the encoder/scale mounting provisions. I would match the tap to the hardware pitch. I can't recall but I think it's all fine thread.


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## gonzo (Oct 30, 2020)

Actually it's M4 - 74. I had to drive 200 miles to find this out!


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## Muda (Mar 22, 2021)

Just wanted to thank you for this post.  Best out there.  Used a similar DRO on my old JMD-18PF but with standard scales.  Z axis was a bit tight. Chose to reinforce the vertical stability of both the scale and the head.  On the Y axis I wanted the scale as far out of the crud stream as possible so I mounted it low and move the head.  The lathe is next but I'm going with a slim magnetic on the cross slide.


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