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PM935 dro scale lengths

Sdmf5150

Iron
Registered Member
#1
I will be ordering a pm 935tv soon and was offered a easson 3 axis dro in exchange for some mechanical work to be done. My question was to any owners of a 935, if they knew the scale lengths that are used?
I doubt the scales that came with this dro would fit because they were bought for a Bridgeport with a much bigger table. The unit is a es12 and has never been used as I was told. Hopefully I could just buy the appropriate scales.
 

ch2co

Grumpy Old Man
H-M Supporter-Premium
#2
There are many members who have cut scales down. Do you know what type of scales they are (glass, magnetic, capacitive)?
Oh, and by the way welcome to the forum. It's a great place for answers no matter how complicated ( or stupid, like the questions
that I ask).
 

wrmiller

Chief Tinkerer
H-M Supporter-Premium
#3
If they are glass scales for a full-sized BP they likely won't work. Especially the x-axis scale. I bought magnetic scales for my 935 and trimmed to length. More expensive, but they fit. :)
 

Sdmf5150

Iron
Registered Member
#4
There are many members who have cut scales down. Do you know what type of scales they are (glass, magnetic, capacitive)?
Oh, and by the way welcome to the forum. It's a great place for answers no matter how complicated ( or stupid, like the questions
that I ask).
I just asked the guy, and he said they are glass scales, so there will be no way of trimming those. I pretty much counted on buying new scales to fit anyway
 

mksj

Active User
H-M Supporter-Premium
#5
I think you may be OK on the Y and Z, the X is probably too long. The PM 935 Z knee travel is 15", full size knee is usually 16", and the Y travel is 12" which is the same as most knee's. The X is most likely too long. There are some postings of people cutting down glass scales, but it is tricky. A new Sino scale is reasonable. I like the ES-12, have one on my lathe, but the newer ES-12B model is a bit nicer and pretty reasonable through QMT. If you needed to purchase 3 new scales for the ES-12, it is probably not worth it, but if just the X than maybe.
 

ronboult

Active User
Active Member
#6
I would be wary of buying Sino (KA300) scales. My ES12 was supplied with two Sinpo scales and one Sino scale for the Y axis.
The Sino scale appears to have only a single pair of black plastic seals which have hardened to such an extent over 2 years that they gape open and no longer seal the scale.
On the other hand the Sinpo with double yellow seals remain Supple and close behind thebread head
Ron
 

Kiwi Canuck

H-M Supporter - Premium Content
H-M Supporter-Premium
#7
I think you will find buying 2 or more scales will cost as much or more than a complete new kit.

Check with Matt at QMT or try these guys, I bought my DRO's from them and was very impressed with their service.

https://www.aliexpress.com/store/gr...57555.html?spm=2114.10010108.100008.18.sRQP14

I ordered my DRO with GS10 scales for my PM935TS , X travel 650mm, Y travel 350mm, Z travel 400mm. (I have them but not installed yet, but believe these are correct)

BTW as mentioned above, I've seen a youtube video of glass scales being cut down, they worked fine so it's possible.

David
 
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