Model Engine Maker
General Category => Chatterbox => Topic started by: steamer on December 27, 2014, 08:32:43 PM
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Just picked up one of these sets as well....I can do metric on the Samantha Bell now as well.
http://www.ebay.com/itm/NEW-METRIC-TRANSPOSING-GEARS-FOR-SOUTH-BEND-9-10K-LATHE-For-Repair-/141519320582?pt=LH_DefaultDomain_0&hash=item20f3357606
Sounds like an easy fix.
Dave
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Nice find Dave! :ThumbsUp:
Don
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You going metric on us Dave?? :lolb:
Bill
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Gotta complete the capabilities! :LittleDevil: Some of the truck is metric...and I have a few changes I want to make.
Dave
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Definitely a worthwhile endeavor then :)
Bill
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I have been eyeing that set for decades, is this the one to buy? What does he mean about the gears not being pinned together?
Mosey
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this set has an issue with the Transposition gears not being pinned together correctly, so are $50 off full price. I figure I can sort that out and save the $50.
There are more of the "defective" sets available at that price...or.
You can buy the "good" set for $200.
This set is a duplicate of the SB set.
The 100/127 gears could be replaced with a 37/47 set and be able to keep the gear guard on......but you need all the other gears as well. I could make all of them, but it's cheaper in time and tooling to just buy it.
Dave
www.tools4cheap.net
Dave
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Cool!
If your mount the metric transposition gears, your overall ratios are then 13% off of the gearbox plate. So, can you leave the metrics on and your speeds and feeds will be slightly off? (Lazy, huh?)
This would be a good time to make all of those W-12 and W-20 bits I have been meaning to make. Collet blocks, arbors, etc.
Mosey
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If you have the "A" the feeds will be altered ...they are more intended for occasional use....for cutting threads.
Yes...now would be that time to cut some W12 or W20 threads.... W20 is a 5 x 45 Buttress thread with a 1.6667mm pitch ...... 8)
Don't even know if it will do that directly. If you put the Transposition set in and it is set for reduction, then set the quick change to 12, and you will get 0.0656" pitch which is near enough 1.6667mm pitch
Dave
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Here's what South Bend has to say on the subject
http://img.photobucket.com/albums/v727/vmil3/SB8tpileadscrewmetricchart.jpg
So we need to make some adjustments to do a 1.667 mm Pitch
Dave
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Set the lathe up to cut 12 threads per inch... 20 tooth on the stud, 56 on the screw. Set the 56 tooth gear to the outside with the spacer to the inside.
Insert a 100/127 or 37/47 transposition pair in place of the idler. The 127 tooth gear engaged with the 20 tooth stud gear while the 100 tooth gear engaged with the 56 tooth gear. 47 to 20 and 37 to 56 respectively.
Set the QCGB to 12 and you will get 1.6667mm pitch ( 127/100 = 1.27 x 12 = 15.24 threads per inch which is 0.0656" pitch or 1.6679 mm pitch)
QED
Dave
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Gearset ordered!
I'll bug you later for the pin fix.
Mosey
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Then I better figure out how to do it! :lolb: Said he'll ship Monday...so some time next week.
Dave
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You are the man!
Mosey
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I haven been changing around the shop and as such have gone away from South Bend for now (I'll miss them). Anyway, I have a set of these that was only used once if anyone is looking to buy as set. Feel free to PM me. Worked great, just sold the SB and don't need them now.
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I haven been changing around the shop and as such have gone away from South Bend for now (I'll miss them). Anyway, I have a set of these that was only used once if anyone is looking to buy as set. Feel free to PM me. Worked great, just sold the SB and don't need them now.
PM sent, I am interested in the gears.
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My gearset arrived today. The pair of big ones are pinned together with 2 pins, but have a slight wobble. What has to be done, replace the 2 pins with tighter fitting ones?
Mosey
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Probably Mosey....I haven't gotten mine yet....hang on a day or so and I'll let you know
Dave
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Not getting my gears until Jan 6th.....can you hold on till then Mosey?
Dave
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OK the tracking number said Jan 6th.....but I got a box from tools4cheap this morning......I'll open it when I get home tonight.
Dave
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Dave,
No problem, I'm hanging on, LOL
Mosey
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Thanks Mosey....got some other toys while I was at it....ON SALE!
Dave
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Alright, got the gears as well as a full set of 3C hex collets! ;D
The transposition pair is wobbly....what I found was the bore on the 127 gear was a touch big for the bushing. This allows the gear to wobble on the bushing....
So my approach will be thus
1. Get rid of the awful silver "Made In China" paint .....Need vomit emoticon....
2. Check both gears for concentricity with the bore. This Is important or you will get drunken threads.
3. Correct the bores IF necessary. This will be done on a face plate indicating off the flanks of the gear teeth with a pin and a dial indicator. Then bore to clean...size is not important.
4. Machine a new bushing to fit the bores and Loctite the gears to the bushing.
5. Insert 1 pin through both gears to complete the repair.
6. Paint a soothing Rustoleum color of your choice....in my case Smoke Gray.
Dave
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Sheer genius!! What I expected. Your instructions will be followed to the letter. I have a gal. of SB Grey.
Thanks,
Mosey
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Just for you Dave
(http://www.sherv.net/cm/emo/funny/1/vomit.gif) (http://www.sherv.net/)
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Just for you Dave
(http://www.sherv.net/cm/emo/funny/1/vomit.gif) (http://www.sherv.net/)
Now that's one even I, the ultimate hater of emoticons, could find plenty of uses for. Can we add it to the assortment available on the forum?
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Just for you Dave
(http://www.sherv.net/cm/emo/funny/1/vomit.gif) (http://www.sherv.net/)
Now that's one even I, the ultimate hater of emoticons, could find plenty of uses for. Can we add it to the assortment available on the forum?
I second it!
:lolb:
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Sounds like a good plan Dave, we need pictures though of the repair and the other goodies that you ordered too.
Love the emoticon Bob!! Happy New Years guys!
Bill
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Got some decent 12 year old libation to contend with at the moment, and then....some wrenching and racing at the New Years Race tomorrow!.....
After that.... Probably this weekend....
My last day at the evil place is Friday! I start the new job on the 12th! Feeling good about that!
Dave
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Mosey...if you get out ahead of me, make the bushing fit like .001 clearance....nice and tight but not too tight for Loctite. That will keep things concentric.
Dave
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Even better than adding it to the list of available emoticons would be a forum software feature that automatically places it before any mention of emoticons or spreadsheets in the text of a reply.
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This is the part where you woke up right Marv?
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This is the part where you woke up right Marv?
???
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OK....got a ME day! wooohoooooo!
Got the 127 tooth gear up on the lathe. to do that I had to drill two 3/8" holes on a 5" dia bolt circle so that I could strap it to a plate.
Once there, I checked the pitch dia with the OD and it was pretty darn good...so I trammed it to the OD...and then tightened the two clamp bolts....takes a bit of jockeying...but I got it to about .0005" eventually.
Then I took just enough of a cut on the bore with a boring bar to clean it up....about .005" as far as I can figure.
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Next up, the 100 tooth gear gets the same treatment....at least as far as checking the run out!...
Dave
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Well it's about time that Samantha Bell got a work out. :stickpoke:
Don
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Right behind you, Dave. My faceplate is only about 7". A pleasure to follow such clear direction along.
My lathe isn't as clean as yours, though.
Mosey
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Oh cool...we got dueling lathes here. We need some banjo music to go along wit it :lolb: It is nice you guys can do this together though...one of the great things about forums like this.
Bill
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And here we are!
the bores ended up at 0.993"...should have just bored them to an even inch...but no never mind
The bore of the bushing is about .627"....and is a good fit on the busing. I measured the old bushing and it wouldn't have fit anyway without boring out....so Kit of parts.....
Now to clean and paint to get rid of the made in china paint! (http://www.sherv.net/cm/emo/funny/1/vomit.gif) (http://www.sherv.net/)
Dave
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Nice job. I've had my eye on that set for years thinking about making it fit my Clausing, I'd have to make a banjo to mount it as well.
Greg
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Greg,
A 47/37 is REALLY close to perfect....The error is about .0002"/foot....so less than the leadscrew error....and it fits under the gear cover a lot better....
Dave
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Bill, duel with Dave? Are you kidding? Just the suggestion caused an earthquake up there last night!
So, here's the project: 2 gears, 127/100 need to be mechanically sandwiched and run concentrically on the back shaft.
The central hub is not correctly attached or concentric.
Remove existing defective hubs and pins
Make and install a new hub to carry the 2 gears, boring out the centers of the 2 gears to accept a new precise hub, loctite and pin them together.
Mount on on the banjo on the lathe (door doesn't clear gears)
Mesh, space, and grease gear train
Paint gears South Bend grey.
Make metric parts :DrinkPint: :DrinkPint:
Dave, sound right?
Mosey
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Sounds like a plan!
Dave
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Yo Robert!
Once you have the two gears running concentric with their bores...and yours may be fine! Loctite the bushing in place with the two gears up against each other tight.
On my pair, the 127 tooth gear bore was too big for the center bushing...so it wobbled and had a lot of free motion about the bushing...even with the two pins in it.
Making a new bushing and boring the two of them out to be sure, solved that problem completely.
Now that they are loctited together, they'll never come apart, but I'll put a pin in anyway.
Does that answer your question?
Dave
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Dave,
Yes, that answers my question. I was puzzled by the fact that my gears barely wobbled at all, so I kept wondering what am I missing? I probably could have Loctited the assembly without taking it apart and been fine.
This job is the easiest, most basic I can imagine...boring 2 holes and making a 1" diameter sleeve.
Well, it's about done, but you didn't mention that getting the gears mounted concentrically to the faceplate was a fiddly PITA!
Thanks for your patience.
Mosey
I did discover that my inside Mike is not measuring correctly, so I will have to service that.
By the way, the cast iron in these gears is very fine grain and nice to cut. :ThumbsUp: :ThumbsUp:
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Thanks for your help, Dave. Ain't they pretty?
Mosey
(http://i908.photobucket.com/albums/ac290/sussna/Photobucket%20Desktop%20-%20Robert%20Sussnas%20Mac%20mini/MetricChangeGears_zps4150d697.jpg) (http://s908.photobucket.com/user/sussna/media/Photobucket%20Desktop%20-%20Robert%20Sussnas%20Mac%20mini/MetricChangeGears_zps4150d697.jpg.html)
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Looks awesome to me! Great Job! :ThumbsUp:
Dave