Author Topic: Old School Sawmill Edger  (Read 18093 times)

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #165 on: December 05, 2019, 01:31:05 AM »
So---It's been a long and uneventful day, but I have two shafts turned to size and ready to have gear teeth cut into them tomorrow. Turning shafts to fit bearings is not one of the machine shop jobs that I really like. I have ruined so many pieces of shafting by trying to get that last thou off the diameter and then ending up undersize. Steel is funny stuff. Unless the lathe tool is razor sharp, it won't cut that last thou--it just burnishes the shaft. Then when you turn it in one more thou, it digs in and takes off more than you wanted it to. I generally take shafts down to about 0.002" oversize, and then work the final bit off with carborundum paper strips until it is a "perfect" fit. Sounds good if you say it real fast, but my thumbs are sore tonight from holding sanding strips.

Offline gbritnell

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Re: Old School Sawmill Edger
« Reply #166 on: December 05, 2019, 12:28:51 PM »
Hi Brian,
You should never try to take .001 or .002 off with the lathe tool. Make your rough cuts leaving .014 stock. Then take a semi-finish cut leaving .004-.006. Mike the part and you should know by that cut how accurately your machine will cut. Now take your finish cut. You can stay .001 big if you want to polish the stock to size but by taking almost 2 identical cuts the part should come out exactly as dialed. Even a worn machine should repeat 2 cuts of almost the same depth. Trying to file and emery .002 off a shaft usually leads to a non concentric diameter.
gbritnell
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Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #167 on: December 05, 2019, 12:34:43 PM »
Thanks George--I know how it's supposed to work, and I totally agree with you. It just doesn't work like that for me. My wife is buying six more tool holders for my qctp for Christmas, and I am going to delegate one of them to a razor sharp tool that only gets used on finish cuts.---Brian

Offline Jasonb

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Re: Old School Sawmill Edger
« Reply #168 on: December 05, 2019, 02:41:20 PM »
Brian, as you like using inserts get one of the CCGT or DCGT polished ones meant for aluminium and non ferrous metals, they will take a fine cut off of stainless and mild steel too.


<a href="https://www.youtube.com/watch?v=LpVtM35GFtM" target="_blank">http://www.youtube.com/watch?v=LpVtM35GFtM</a>

Good enough to sneak upto 10mm (0.3937" on my tenths micrometer)





Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #169 on: December 05, 2019, 05:53:44 PM »
I've had a very gearish morning. We have one set-up shot and a shot of the three finished gears. No real excitement, I have the entire procedure written down in my "Gears" notebook. I don't do this very often, so it's nice to have something written that I can look over before I start machining. There is one more gear, made from brass, but it's a big one, over 4 1/2" diameter. I called my metal supplier to ask how much it would be, and he said "If you have to ask, you can't afford it!!"I have a good size piece of 1/4" brass plate that some kind soul gave me a few years ago, so I am going to laminate two pieces together and cut my gear from that. Now I have to go shovel the front step and go for my fat mans walk.


Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #170 on: December 05, 2019, 09:30:04 PM »
Whenever I cut a pair of gears, I always drill and ream two holes the exact calculated distance apart in a piece of scrap material and insert the gears and shafts, then turn them by hand to test how they mesh. Most times it works alright, but I have been fooled in the past. I can generally live with a bit of extra "lash" in the mating gears, but when they are a bit oversize, it gets ugly pretty fast. If they are a bit oversize, you can either set them back up in the lathe and recut them, which is a pain in the $#@%, or you can change the design of the housing a bit to accommodate them. Also, you can see my two pieces of 1/4" brass plate, rough cut to 4 3/4" and joined with J.B.Weld, then clamped. I will also bolt them together after they set up for 24 hours.


Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #171 on: December 06, 2019, 10:56:55 PM »
So here we are, ready to cut the 108 tooth gear. The two pieces of 1/4" brass plate were "glued" together with J.B. Weld, clamped and left overnight under a heat lamp. The outer circle of bolts hold the two plates together permanently--I don't trust any adhesive in an application like this. The inner circle of bolts pass through the plates and are threaded into a 1.5" diameter steel stub-shaft that is held in the jaws of the chuck on my rotary table. Before the stub-shaft was bolted in place, the brass plates were set up in my lathe 4 jaw chuck to drill and ream the 1/2" center hole. The stub shaft was also drilled and reamed for a 1/2" shaft, and you can see the end of it sticking out past the face of the brass plates. The big deal here is to achieve absolute concentricity before I start to cut the gear teeth. A dowel with a pointed end was first secured in the chuck, and then the center of the cutter was adjusted to be perfectly horizontally in line with the point on the dowel. Then the table was fed towards the column in the Y axis until the major diameter of the brass just touched the major diameter of the cutter. Then with the table cranked back out of the way in the X axis, the table was advanced 0.089" in the Y axis. This is the depth of cuts to be made. The table stops were set so that the cutter just cleared the brass part in each direction on the x axis. I am now ready to start taking full depth cuts every 3.333 degrees. This rotational distance is set by using the divider plates on the front of my rotary table.

Offline gerritv

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Re: Old School Sawmill Edger
« Reply #172 on: December 07, 2019, 12:52:28 PM »
Looks like a rock solid setup.
I assume there is a DONOT DISTURB sign on your shop door today? The first time I cut a 60 tooth timing pulley I even removed the phone from my shop :-)

Gerrit
Don't confuse activity with progress

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #173 on: December 07, 2019, 01:38:23 PM »
GerritV--well, it's something where you don't want your concentration broken, that's for sure.

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #174 on: December 07, 2019, 05:13:11 PM »
So, here we are with the completed gear-train for my new gear reducer. I cut the 108 tooth gear this morning, and after finishing it I set all of the gears up in the correct relationship to each other, and took it for a test drive on my milling machine.
<a href="https://www.youtube.com/watch?v=AX3ZXzG1Wck" target="_blank">http://www.youtube.com/watch?v=AX3ZXzG1Wck</a>

Offline Admiral_dk

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Re: Old School Sawmill Edger
« Reply #175 on: December 07, 2019, 07:11:22 PM »
Nice result with the gears Brian  :ThumbsUp: you should be happy with them  :cheers:

Still following along  :popcorn:

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #176 on: December 07, 2019, 10:22:51 PM »
The two main outer plates of the reducer have the exact same outer profile. Of course they have different cavities machined in the in facing side because of the mish mash of bearings I used. The easiest way for me to do this is to extend the small diameter of the blind bores completely through the plates. That way I can pick up on the bores when I flip the plates over to mill the cavities. There will be no pressure in the reducer, just lots of gear grease, so if I do extend the bores all the way thru each plate, I can glue in plugs after the fact. This makes my job a lot easier, and takes nothing away from the functionality.
« Last Edit: December 07, 2019, 11:05:11 PM by Brian Rupnow »

Offline Ye-Ole Steam Dude

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Re: Old School Sawmill Edger
« Reply #177 on: December 08, 2019, 12:14:41 AM »
Hello Brian,

Still following along and I love your evolution of improvements to this machine.

Have a great day,
Thomas
Thomas

Offline Brian Rupnow

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Re: Old School Sawmill Edger
« Reply #178 on: December 08, 2019, 12:07:41 PM »
Thomas--how is your back? I have been doing my 1 1/2 mile "fat mans walk" since May, and have lost 41 pounds. This makes a remarkable difference in how my back feels at the end of the day. No more pain is so amazing I can hardly believe it. I didn't reach my goal, which was 50 pounds off by the end of November, but I will keep up my walk for the rest of the winter at least. What I would really like to see is a weight of 200 pounds by spring. I just love machining, and it's so nice to be able to stand at the lathe or mill and know you aren't going to have to set on a heating pad and take pain pills every evening.---Brian

Offline Ye-Ole Steam Dude

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Re: Old School Sawmill Edger
« Reply #179 on: December 08, 2019, 01:48:29 PM »
Thomas--how is your back? I have been doing my 1 1/2 mile "fat mans walk" since May, and have lost 41 pounds. This makes a remarkable difference in how my back feels at the end of the day. No more pain is so amazing I can hardly believe it. I didn't reach my goal, which was 50 pounds off by the end of November, but I will keep up my walk for the rest of the winter at least. What I would really like to see is a weight of 200 pounds by spring. I just love machining, and it's so nice to be able to stand at the lathe or mill and know you aren't going to have to set on a heating pad and take pain pills every evening.---Brian

Hello Brian,

I haven't felt this good is at least 4 to 5 years. Not standing on my feet 8 to 10 ours a day out in the shop ( which I miss so much ), now doing my light exercise and big change in my diet ( now down to 200 ) which has help me loose a bit of weight but still staying plenty busy. I hope you stay with your diet and can get down to your desired weight goal. I am really enjoying following on this build and hope to see a video of it throwing sawdust everywhere  :lolb:

Have a great day,
Thomas
Thomas

 

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