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Re: Bridgeport Spindle Encoder Design
Posted: Thu Aug 16, 2018 10:32 pm
by ScotY
Hmmm, that might make an encoder setup on my new mill relatively easy. It finally arrived yesterday and working on getting it set up. Would love to find an encoder solution so I can convert it to run off an Acorn. Thanks for the info. I may bug you later for help with selecting the right parts.
Re: Bridgeport Spindle Encoder Design
Posted: Wed Aug 29, 2018 1:42 pm
by CRM
What an excellent post! I have been pondering how to do a spindle encoder on my SWI Trak DPM retrofit on and off for quite some time now. This is such an elegant solution.
You do realize that imitation is the finest form of flattery, right?
Re: Bridgeport Spindle Encoder Design
Posted: Wed Aug 29, 2018 2:53 pm
by tblough
CRM,
If it helps, I've attached the Solidworks file of the encoder modification. Let us know how you make out.
Re: Bridgeport Spindle Encoder Design
Posted: Thu Aug 30, 2018 7:19 am
by CRM
Tom, thanks for posting up the files. The RLS incremental Encoder and RLS Magnetic Ring import fine, but I was unable to import the 2J Spindle Drive Axial Encoder modification assembly file. Doesn't that assembly file also needs every individual part file that makes up the assembly in order to import?
I don't have solidworks, but I use my CAD/CAM software (GibbsCAM) to do quite a bit of solid modeling. Gibbs uses the modeling kernel of Solidworks, so file importation has always been very compatible in the past. Admittedly, I mostly import individual parts most of the time, not assemblies.
Re: Bridgeport Spindle Encoder Design
Posted: Thu Aug 30, 2018 10:05 am
by tblough
Dean,
I did a pack and go which should have grabbed everything. Excluding the RLS components, everything else in the assembly was virtual - meaning the parts were contained in the assembly file and did not exist as separate part files. That may have been the problem. Try the zip attached to this post where everything has been saved in individual part files.
Re: Bridgeport Spindle Encoder Design
Posted: Thu Sep 13, 2018 6:30 pm
by Reedfirst
Wow, what a fantastic solution to adding a spindle encoder to a Bridgeport Head.
I just need to find some access to another mill to machine the encoder mount and the split collar while mine is apart.
Thank you for sharing!!
Re: Bridgeport Spindle Encoder Design
Posted: Fri Sep 14, 2018 8:47 am
by martyscncgarage
Very nice Tom. What did the encoder assembly cost again?
So the effort was to make the aluminum collar for the encoder ring to mount to, and a place to mount the read head. Was read head placement fairly forgiving?
The other effort would be to remove the motor housing from the head.
Kit it up and sell them....
Re: Bridgeport Spindle Encoder Design
Posted: Fri Sep 14, 2018 9:38 am
by tblough
Marty,
90% of the work was tearing the head down, but I was doing most of that already to convert the varispeed head into single speed. Fabricated parts consisted of the clamp collar for the encoder ring, the mounting base for the read head, and drilling and c'sink/c'bore three holes in the bearing carrier. None of these parts see any loading so aluminum is perfectly fine.
The read head mounting base took care of the radial alignment of the read head and encoder disc, while the ride height was set with a feeler gauge and simply tightening the clamp collar. Total cost of the read head was $200 including shipping from Slovenia. Another $100 for the M12 X-Coded CAT6 Ethernet cable and connector to hook it up. I cut the RJ45 off the other end and soldered on a DE9 to fit the ALLIN1DC encoder input.
This should work for just about any Bridgeport/BP Clone as everything is in the lower head (the "J" part) so the fact that the machine was 1Hp, 2Hp, belted, or VS should not make a difference. You should probably verify the worm diameter and the bearing carrier ID before making any parts though as there's no guarantee the clones copied the Bridgeport to that extent. You probably don't want to do this if you are only doing a 2-Axis conversion. This mod completely removes the stock power quill feed.
Re: Bridgeport Spindle Encoder Design
Posted: Fri Sep 14, 2018 9:53 am
by martyscncgarage
tblough wrote: ↑Fri Sep 14, 2018 9:38 am
Marty,
90% of the work was tearing the head down, but I was doing most of that already to convert the varispeed head into single speed. Fabricated parts consisted of the clamp collar for the encoder ring, the mounting base for the read head, and drilling and c'sink/c'bore three holes in the bearing carrier. None of these parts see any loading so aluminum is perfectly fine.
The read head mounting base took care of the radial alignment of the read head and encoder disc, while the ride height was set with a feeler gauge and simply tightening the clamp collar. Total cost of the read head was $200 including shipping from Slovenia. Another $100 for the M12 X-Coded CAT6 Ethernet cable and connector to hook it up. I cut the RJ45 off the other end and soldered on a DE9 to fit the ALLIN1DC encoder input.
This should work for just about any Bridgeport/BP Clone as everything is in the lower head (the "J" part) so the fact that the machine was 1Hp, 2Hp, belted, or VS should not make a difference. You should probably verify the worm diameter and the bearing carrier ID before making any parts though as there's no guarantee the clones copied the Bridgeport to that extent. You probably don't want to do this if you are only doing a 2-Axis conversion. This mod completely removes the stock power quill feed.
Agreed. Your solution works for CNC knee mills where the transmission has been removed.
If you haven't already, post the source and ordering information for the encoder. I look forward to seeing your machine do rigid tapping. Thanks for taking the time to document and share the journey.
Marty
Re: Bridgeport Spindle Encoder Design
Posted: Fri Sep 14, 2018 1:13 pm
by tblough
The encoder ring and read head were less than $200 including DHL shipping from Eastern Europe. The read head was an RLC2IC with RS422 5V interface, 6-Bit (06B) interpolation, 1µs edge separation (C), no connector, with reference mark, and no special requirements. Actual part number was RLC2ICA06BC00A00. The encoder ring was an MR axial magnetic ring, 50mm OD, 2mm height, 40mm ID, with reference mark, 72 poles, stainless steel with back adhesion tape. Part number MR050C040A072B02.
Sorry, posted part numbers earlier in the thread but no link. Here it is:
https://www.rls.si/eng/products/rlc2ic- ... ic-encoder