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Post by toynrnd on Feb 7, 2006 12:36:17 GMT -5
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Post by What It Was on Feb 7, 2006 20:27:11 GMT -5
Those are two good sites and I appreciate it... I still have to find the actual dimensions on these axels (44,60,9). Once I do that it's nothing but custom home/shop work. (The axels are another thing)... I'll have to get a list of lengths and compare it to the stock length dana 30 axels... seeing that I have to cut one side down and extend the other tube on th 9". Hopfully there are some axels that are out there that are REALLY close to the dimention needed.... If something is close (A little too long), I'll chuck it up in a lathe trim it and if need be I'll mill the splines a little here and there to meet specs etc... I'll make a Rear Ford 9" work as a front axel... I need some DANA 60 knuckles... I might have to go to New York and pull parts... off of those bigger older trucks that have rusted out!.
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Post by Chuck on Feb 8, 2006 11:27:52 GMT -5
There are a few good companies that do custom axleshafts, and you might be able to get blanks from them. Most are induction hardened only, the only company I know of offhand that through hardens is Superior. I have no idea what sort of rockwell numbers they're talking about -- can you mill a blank that's already been hardened? Machine work is an area I'm sorely lacking knowledge on, that's something I'm trying to fix as quickly as possible. ;D
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Post by What It Was on Feb 8, 2006 12:46:42 GMT -5
Yeah you can machine hardened material we have special inserts that we use $$$ but with all hardened stuff it's time consuming and rough on the cutters.... You can also use special cutting stones.. $$$$$ With Inserts You have to turn it at slow RPMS and flood it with special cutting/coolant in-order to save the wear on the cutters... Anything fast will throw sparks and eat the cutter like no tomorrow!!! After it's been cut I'll do the calculations and bake it and dip it to the right hardness... (Like I said, it takes a long time)...
Most people wont mess with hardened materials... (In the long-run it's expensive.. When I work on crane parts... sleeves and cylinders etc... Man.. it takes forever... and they're only case hardened... But the cases are a bit thicker than the norm. I'm looking at getting a lathe for my place... so if you guys need something made... let me know and I'll be sure to out bid the competition... (keeping more money in your pockets as well as mine... it's like we both win). Plus I'll use the higher quality material... not the bottom crap that a lot of companies pass off... You'll be surprised at what they sell... Just give me the dimensions and it's as good as gold!!!!
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Post by Chuck on Feb 9, 2006 9:47:04 GMT -5
Yeah, you could definitely make back your initial outlay over a while doing side jobs (particularly if you could scare up the facilities to heat treat shafts and gears), and I'm certain folks here have enough projects they'd tackle at a reasonable cost to keep you busy. Shoot, I'd probably trade some free design work (I'm a structural engineer) for a chance to learn the lathe. ;D
Are you going for a basic lathe, or a good screw and gear cutter?
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Post by What It Was on Feb 9, 2006 10:43:26 GMT -5
Working a lathe isn't hard... Once you have the basic understanding and knowledge of it's functions.... it's butter! The Lathes I use are good... I can cut any type of thread.... (Standard,metric,straight, acme etc). we have a couple that are belt driven.... (Not bad for light work)... but most of them are gear driven. As for making gears on a lathe.... Well, that might be hard unless you have a mill/lathe combo... even then I'm not sure.... We cut our blanks on the lathe and then we make our gears on the horizontal mill. Making gears is a pretty detailed operation to say the least.. you have to know a hand-full of formulas and then cross reference everything... and I do mean you gotta know the obvious and formulas,
ie: number of teeth/outside diameter/Addendum/dedendum/circular pitch/diametral pitch/pitch diameter/chordal thickness/working depth/clearance/whole depth..etc etc.. then you have to know the common numbers 3.1416 (Pie) and when and where to use it.... man, I could go on and on but, it wouldn't be worth it... right now!... I'll get a picture(s) of a lathe that's older and newer and I'll write each part and their functions for you. and then I'll post them.
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Post by Chuck on Feb 13, 2006 10:48:53 GMT -5
I've been doing a bunch of reading lately, and I've seen a few interesting attachments built for the lathe that would let you do full gear work without a separate milling machine -- the best options seem to be a separately driven flycutter adapted to mount to the slide rest, that way you can still use your division wheel and you can do the cutting immediately after turning so you don't have to worry about re-centering the work, single operation ... the setups I've actually seen drawn out so far all look like they're only good for straight cut spur gears as-is, but there are probably ways to adapt to helical cut too if you're creative.
I've been doing a little hunting through older lathe and shop books, it's amazing what solutions folks came up with when their shop could only really afford one machine (one book I'm reading through right now has mostly treadle-operated machines in examples!). Having a lathe, milling machine, and everything else is handy, but it seems like with some serious creativity the lathe alone can do just about any job ... if you make it to next month's meeting, I'll have to try and remember to bring the book by so you can get a look at some of their milling and cutting attachments. Neat stuff!
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Post by What It Was on Feb 13, 2006 10:57:54 GMT -5
yeah man.. sounds like good stuff... I learn something new everyday with Machining... That's why it's an awesome job... I'm curious now.... I have to see how they're setting this mill work up in a lathe.
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Post by Chuck on Feb 13, 2006 11:44:37 GMT -5
Well, I've seen a couple of variations. One is set up to cut radial slots and dovetails, it's an assembly that mounts parallel to the axis of centers on the slide rest. In the ancient diagrams I'm looking through, it's driven off an overhead shaft from the same power source as the mandrel/spindle would normally be if it weren't disconnected. You use a rotary or flycutter just like you would in the milling machine. I suspect you could also use it to drill any circular pattern of holes your dividing wheel could be set up for, at any radius the slide rest will allow it to reach ... The more involved setup allows full milling for small objects, at least. You could probably build some decent capacity into this if you had a lathe with a big enough bed and slide rest. With this setup, you're not even using the headstock or tailstock, you have another upright that mounts to the lathe bed in front of the headstock (or in place of, for lathes where they're mounted just like the tailstock). This upright supports an overreaching horizontal arm set in a vertical set of ways, height of which is controlled by a vertical screw with a set screw. The horizontal arm supports a cutter bar on its own set of centers, driven (in the case of the example I saw) by chain from underneath the lathe bed or from the same overhead shaft you would use to drive the first milling cutter, with a spring loaded chain tensioner on the slack side. This upright lets you mount the cutter much higher than the normal centers of your lathe. You then adapt a larger bed for your slide rest, on which you can bolt whatever you're milling. Your travel would be limited by the travel and capacity of your slide rest ... The third option that I know of for cutting helical gears on the lathe is hobbing. I'm not very familiar with the details of how it works, but I know making the cutter is more work than making the gear itself. The cutter is basically a worm gear with multiple cutting faces in the "tooth", and is set so that the pitch line of the worm gear is on level with the intended pitch circle of the gear you want to cut. I believe the way this would work is you'd mount the hob cutter on the milling upright, with the gear mounted to the slide rest milling table on a special set of centers dogged to the table. The gear blank is free to turn. You start the cutter, then advance the gear blank along its shaft axis into the cutter, which begins working on the face of the blank at the edge. The cutter should both cut and rotate the gear, cutting all teeth in one operation, so as long as you get the pitch lines/circles set right, you get a very consistent set of teeth. The entire gear gets cut in one operation, as the cutter passes through the gear face and out the other side ... you can use the same hob to cut any diameter (number of teeth) gear with the same dimension tooth, you just tool up the blank and then set it up for the pitch circle diameter of the size gear wheel you need. I have a decent little bit of book knowledge about some of this stuff, what I'm really lacking is any practical experience. Closest I've really come to a lathe is drooling over one or two at Harbor Freight.  I'm kicking myself for not shamelessly taking advantage of a friend's access to a good size Atlas lathe when he was still stationed in the Coast Guard ... he had access to it, but never got off his butt and learned to use it, so now he's hunting for ship mechanic's job instead of a machinist's job, and I still have no lathe experience. Lessons learned ...  |
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Post by What It Was on Feb 13, 2006 19:28:00 GMT -5
The thing you mentioned is a versa-mill.. Only a modern versamill has it's own power and is a variable speed.. (Belt driven). It mounts to the cross-slide where the tool post sits.. We use that on a ship for cutting key ways in shafts... And more. You can call me old school because I'd rather cut my blank in the lathe and then cut the gear(s) on the Horizontal mill... A Hob is nice... It seems easier to use a lathe and a horizontal mill rather than setting up all of that on a lathe.. By the time you do all of that (set-up for milling) on a lathe you could've been cutting the gear already.... As for cutting the gears... It's time consuming making pass after pass after pass!!!! And then checking the gear teeth with a tooth caliper... But, if your math is correct and your set-up is good and dialed in... It'll be butter!!!
Every so often they have mills and lathes in the Tidewater Post for sale... They had a mill/lathe/other odds and ends for $2000... It'll be a great investment if you're serious about learning and eventually making things!!!! ($2000 is a small amount to pay-off... A few parts out the door and it's paid for).
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Post by Chuck on Feb 16, 2006 19:18:37 GMT -5
I know hobbing has been around since before horizontal mills were particularly common (most people were still using shapers in preference to mills, there's one for ya), but I agree using a mill is probably a lot more common (and a heck of a lot easier). The advantage to the setup above is basically that you can do the whole job with a lathe if you can't afford a mill or don't have space for one ...
... plus, it's just neat to see how stuff was done in (in this case) 1907. ;D
I keep drooling over lathes in the trading post, and I think that's probably the way I'll eventually go. If I can get my next degree done end of summer, hopefully I'll be due for a raise next fall, and I can start setting aside a little lathe money. ::grins::
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Post by What It Was on Feb 16, 2006 19:23:36 GMT -5
I hear ya about the Lathes in the Post... I've been keeping an Eagle eye on that section.... You know, On ebay I seen a couple bench top lathes (9" high 32" long... 24" in-between centers) for $400-$500....... I think the swing was 6 1/2"... But, it'll do basically what you need around the garage... Plus it's a good starting lathe to practice on.
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Post by Chuck on Feb 18, 2006 9:21:09 GMT -5
Not bad at all! When the time comes, I'm hoping for just a little more length between centers, though I'm sure I'll end up paying for it. The longest thing I could reasonably see wanting to turn is an axleshaft, and the longest shaft in anything I'd be likely to have (Ford 10.25" full floater, we already have two sitting on the property with a third on the way) is just under 38". I think most of the stuff I'd be likely to do would be a good bit shorter, but I haven't been able to think of anything longer I'd be messing with. That would let me shorten and re-spline shafts, or re-drill lug patterns with the dividing wheel ... Either way it's going to be a ways down the road. All my play money right now is going into getting the Bronco back together with improvements (just picked up my second 130A junkyard alternator yesterday (plus one to swap onto the Mustang), making the bracket adaptor for dual alternators on the Bronco should be fun) ... and once the Bronco is done, it's time for a rear end rebuild with new axleshafts and a tranny rebuild in the Mustang .... ;D |
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Post by What It Was on Feb 18, 2006 11:53:50 GMT -5
NICE.... I'm slowly getting my stuff done or prepared for being completed... When she comes together I'm sure it'll happen quick... and I'll be fixing/modifying things again...hahahaha
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Post by What It Was on Feb 26, 2006 1:44:29 GMT -5
Well Late last night I got a hold of a set of AMC HIGH COMPRESSION HEADS (3196291-C)!!!..... I took some measurements from top of the stud boss to the flat spot for the head bolt.... On the Early heads (Single style) they averaged .730" in height.. and on the later heads (bridged) they averaged .980" in height..... SO, in-order to run roller rockers on a bridged style head (74 and later) I will have to have the heads milled down to the early specs which will be .250" less.... I then have to mill off the thickness of my guideplates= .125" and then a little extra .050"... for a total of .425"... Which is a lot!!! But, I figure I'll go with .325" first and bolt it up and if more needs to come off then more will... But, I have to make sure that my valve geometry is correct... I have comp cams adjustable pushrods to check.... so that'll help. I have to dig out a stock rocker arm and bridge... this will give me the proper fulcrum (sp) height etc... (Just to make sure I don't have too much milled)... If too much is milled then chances are the holes that will be drilled and tapped will hit the water Jacket and then I'd have to seal those bolts and add hardened washers in-order to get the proper height.... FUN FUN!!!! I went with Harland Sharp 1.7 Ratio 7/16" Roller Rockers and what I should've done was bought the pedestal mounted roller rockers... It would've been a little cheaper (Only because I only paid $200 for this set of Harland Sharp).... Which is a steal!!!! I couldn't pass it up!!! Anyway, the machining is almost complete... Next get it here a few more odds and ends from summit and various other places and she'll be ready to go in and fire up!!! It'll be sweet... I'll take pictures of the build-up on the motor... and film a couple of shots of the break-in period and then her idle... She's gonna be mean!!! My neighbors will officially hate me or at-least strongly dislike me!!! Soon my interior will be in.... and then I can whole-saw some holes for the roll cage to be ran through and welded to the frame... It's gonna be a sweet toy.. I'll be sure to have a couple extra driveshafts etc.. Because I know it's only a matter of a few hours on a good trail that something is going to give under the brute strength and torque.
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