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General Forestry => Sawmills and Milling => Topic started by: jimbarry on June 27, 2023, 08:49:11 AM

Title: BMS250MU Woodmizer sharpener - issues
Post by: jimbarry on June 27, 2023, 08:49:11 AM
Yesterday I began experiencing similar issue with the 2018 sharpener, issue with the proximity switch and blade push motor. After turning on both power switches, when turning the dial switch to operate the blade advance motor, power would shut to the P2 relay.
Several phone calls to Wood-mizer in the US (Jason in the elec dept, very helpful) and we were able to trace and check the electrical route from the transformer (120V in, 14V out), to its connection to the circuit board (lower left corner (11U terminals, I think), ok at 14V. Then to the F2 fuse (behind the little circuit board), ok at 14V in and out. All good to that point. From the fuse to the terminal points that control the blade push motor there's a voltage drop down to about 8V. It should be 14V. So his recommendation was a new circuit board and new relays (just in case). I already did a board swap on the other sharpener last year. Fun times. :-X At least now I have a better understanding of how this thing works.
Title: Re: electrical issue with 2018 BMS250MU Woodmizer sharpener
Post by: MattM on June 27, 2023, 09:06:53 AM
You definitely don't have much luck with those sharpeners do ya Jim   :embarassed:
Title: Re: electrical issue with 2018 BMS250MU Woodmizer sharpener
Post by: ladylake on June 28, 2023, 02:25:48 PM
 Matt  If you look at the bottom of this page he is not the only one having trouble with that sharpener.  Steve
Title: Re: electrical issue with 2018 BMS250MU Woodmizer sharpener
Post by: jimbarry on July 09, 2023, 02:06:36 PM
A video on swapping out that circuit board on the BMS250MU. Jump to 5:40 for the circuit board video.

20230708 Logs, circuit boards and broken teeth - YouTube (https://www.youtube.com/watch?v=hBVAGyfiWyI&t=340s)


Title: Re: electrical issue with 2018 BMS250MU Woodmizer sharpener
Post by: ladylake on July 10, 2023, 05:49:33 PM

It's amazing how complicated they made a sharpener.  Steve
Title: Re: BMS250MU Woodmizer sharpener - issues
Post by: jimbarry on July 17, 2023, 03:37:55 PM
Today's adventure of sharpening produced this result. The blade pusher broke.


(https://forestryforum.com/gallery/albums/userpics/20037/20230717_162353-bms250mu-blade-pusher.jpg?easyrotate_cache=1689622634)
 
(https://forestryforum.com/gallery/albums/userpics/20037/20230717_162745-bms250mu-blade-pusher.jpg?easyrotate_cache=1689622635)
 
(https://forestryforum.com/gallery/albums/userpics/20037/20230717_162756-bms250mu-blade-pusher.jpg?easyrotate_cache=1689622636)
 
Title: Re: BMS250MU Woodmizer sharpener - issues
Post by: tawilson on July 17, 2023, 10:14:35 PM
Jim, I  think my sharpener came with too much clamping pressure, thus causing the roll pin backing out issue. I backed mine off quite a bit with no ill effects. I definitely haven't put the hours on mine you and others have but just wondering if this could be related. It's been a while but I don't recall finding anything at the time showing how to adjust the clamp pressure.
Title: Re: BMS250MU Woodmizer sharpener - issues
Post by: ladylake on July 18, 2023, 04:45:47 AM

 It looks like the  grinding  wheel was hitting on the pusher.  Steve
Title: Re: BMS250MU Woodmizer sharpener - issues
Post by: jimbarry on July 18, 2023, 05:00:37 AM
Quote from: ladylake on July 18, 2023, 04:45:47 AM

It looks like the  grinding  wheel was hitting on the pusher.  Steve
Seems to be that's the case @ladylake (https://forestryforum.com/board/index.php?action=profile;u=633) . Both the older and new model (moreso the new model) struggle with that issue when dealing with deeper gullet profiles like 7º or 13º. Most of what I do is 10º and never seen it as an issue. Also, the occasional blade that's been badly welded or re-welded with a shortened gullet can sometimes cause a strike to happen.
Title: Re: BMS250MU Woodmizer sharpener - issues
Post by: jimbarry on July 18, 2023, 05:02:10 AM
Quote from: tawilson on July 17, 2023, 10:14:35 PM
Jim, I  think my sharpener came with too much clamping pressure, thus causing the roll pin backing out issue. I backed mine off quite a bit with no ill effects. I definitely haven't put the hours on mine you and others have but just wondering if this could be related. It's been a while but I don't recall finding anything at the time showing how to adjust the clamp pressure.
Yes, the clamping pressure is adjustable. Parts #11 I believe. Seems to be ok for these machines. Worth a re-check though. 

(https://forestryforum.com/gallery/albums/userpics/20037/diagram-clamp-assembly.jpg?easyrotate_cache=1689671161)