Atlas 7b tweeks

C-Bag

Ned Ludd's bro
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Feb 9, 2017
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hi all,

I've just completed going through a new to me 7b. It was rescue I got in a barn sale. It had obviously not been used in possibly decades. After a thorough cleaning, a new start cap on the motor and a couple repairs to like the motor wiring, the tool post gib and the hub crank screw, and assorted stuck things, I was ready to make some chips.

I did a couple of passes on some aluminum I had. The finish is the best I've ever been able to achieve with any of my machine tools. But up careful inspection on the surface plate I noticed there is a pattern. The first 1/4" of the pass is crazy flat like within .0002 then there's very slight chatter then from there on there is up to .004 total wander. Even though it's still like a mirror finish. Needless to say this is puzzling.

As I was doing this I also started tightening up the gibs and rechecking. The one thing that I need to replace is the feed nut as it's definitely worn enough the internal threads are sharp, not good on a acme thread.

I'm wondering if the table foot is the culprit of the sudden aberration? It was stuck in the up position before I went through it and the bottom of the foot and the surface has some long scrapes from chips or dirt stuck between the surfaces. Do you guys use the foot on your shapers?
 
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A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.
Img_1921.jpg


I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.
Img_7597_zpscb8b5dd7.jpg


Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544

DSC00396_zpsllty3pkw.jpg
 
Thanks for your reply. Nice looking machine. In reading the manual I saw the layered shims for the ram. So it made sense when I pulled the ram and saw a loose one on each side. What kind of play should you have? There are no wear ridges on any of the ways.

The stand it came on was I think an old teletype stand. It was made just to the length of the 4 hold down bolts so it should be supported all the way out to the foot. im also going to have check and do something with the foot and the surface it runs on as both are rough as a cob.

I can see where the extra quick locks on the head gib make a lot of sense. Also some larger dials for the head and the cross feed are on the list after the feed nut and squaring away the stand and getting the foot and it's surface right. In talking to a guy who deals a lot of parts for 7b's he sees a lot of them modded. What other mod's have you done?
 
Oh, and I forgot another, what did you do to keep the jackshaft from slinging oil all over? Mine had felt pads and one was mangled and felt is not a seal. I half hearted try at some o rings but that's a fail. I also will be making an oil tray for it to sit on as if properly oiled it makes old motor cycles look drip free :)
 
Checking Connely's book, 0.oo1" to 0.0005" would be correct clearance if properly scraped.
 
I use the foot all the time too.

Sounds like good advice from all the above.

Sent from my Moto G Play using Tapatalk
 
Thanks Rob. I found that and dl'd all the shaper books when I was on the hunt for the correct starter cap for the motor. There are some interesting mod's like the one for a auto down feed for the cutter head.

I got a chance to check the play on the ram and I had .005 with ram retracted and around .001 fully extended. I have some wear damage on the cutter end of the ram upper ways. I suspect it got run with some of the accumulated gunk on the upper way and I'm going to have to scrape in the upper ways and the retainers. The shims are kinda mangled and were not the same on both sides. I have some shim stock and will probably have to make new shims once I get things more squared away. I continue to cruise eBay for shims and maybe some will pop up. But I don't think making a set of shims will be that big a deal.
 
Think you can get the layered shim stock from McMaster-Carr, although I used the plastic shim stock that I had on hand. As far as mods I did quite a few, first increased the oil channels on the ram ways, lengthened the horizontal ones and added vertical ones, made new sliding yoke block with oil ways to the yoke in a "v" pattern with a large resivour for oil, (I think that lack of proper lubrication is a big problem with these shapers) , surface ground or hand scraped all way surfaces, made new top slide screw/nut with ball bearings mounting and adjustable bigger dial , added locking screws for the top slide, added needle bearings on all trust surfaces and many more. I basically started with the castings and built a shaper without regard to building to a price, with is what Atlas did.
 
Do you have any pics of the upgrades in progress and if not could you take some close up pics of the mods in place?

Thanks
 
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