Mounting a spindle encoder with pdb

[Cad cam man]

Ok guys I need help on this one. I am trying to mount an encoder for spindle feedback on my pm727v milling machine using a belt and pulley system. I plan on adding a power draw bar tool release system in the very near future. If I add the encoder now before the pdb I will have to redo everything because the encoder will be in the way , so I want to make it possible to add the pdb after I add the encoder . I dont know how or where to put the encoder so it will be out of the way of everything. Has anyone seen or know how to go about doing this ? Can it be done ? I am worried about the pulley that would be connected to the drawbar that moves ? I dont want the movement of the pdb to damage the encoder. Any suggestions???

 

[Karl_T]

I have done this on two machines now. You have to get real creative on attaching the pulley to the outside of the spindle and leave room for the drawbar. I think i may have posted the second one here, I will look right now.

edit - found it

Vectrac CNC Knee mill refit from Fanuc 0M to Camsoft

Spent the last several days mounting an encoder to the spindle. had to get real clever here. Only got about 1/4" of the top of the hollow spindle exposed and it can't get in the way of the tool changer. The pics show the parts and the final completed project. A spindle encoder really increases...

www.hobby-machinist.com

 

[Cad cam man]

Yeah your right about getting creative...does the pdb movement effect the encoder when it moves?

 

[Karl_T]

On the above project, i ended re doing the air cylinder on the drawbar for another 1/4" of stroke so it would always engage. the pulley was 3/8 wide and caused trouble at first.


NOW, I remember what i did on the excello 20 years ago. It had even less to grab. I used the taper lock bushing idea here. Two small bolts pulled the timing pulley into a matching taper hub. The hub only had 1/8" of spindle tube to grab. I am still using this mill on a regular basis. On my way out to the shop right now to run it.

 

[Cad cam man]

Woah !!! Thats a 1 of a kind mount job you got there . I see now what you mean about being clever and really thinking outside the box. The pdb is a bit different than the 1 you show in the picture. I have attached a picture of a pdb alot like what I will have im just not sure how to go about mounting a encoder to a spindle shaft that will be moving. The picture is from a guy on YouTube his channel is named Practical Renaissance