# QCGB Question



## RonRock (Feb 25, 2017)

I'm going through my 1937 doing a refurb and paint.

I am having an issue with 1 gear in the QCGB. I had to use a punch to get the shaft out. And am now trying to determine if this is as designed or something I need to deal with.

Here are a couple pictures, hopefully they will tell the story.











And one more just for fun,


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## T Bredehoft (Feb 25, 2017)

Ron, your pix take forever to load, I gave up on the second one, can't see the 'story' in the thumbnails.

How now?


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## CluelessNewB (Feb 25, 2017)

I may be missing something but I don't really see anything out of the ordinary, maybe some sort of description would help.


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## RonRock (Feb 25, 2017)

Sorry guys. Don't know why they would be slow to load.

I guess I didn't fully explain my question.

Is the gear that I show supposed to be a press fit on the shaft? Or should it be a slip fit like all of the other gears in the QCGB?

I am unable to get it to slide onto the shaft. Sure I can press it on, that is how I took it apart. But I'd rather have it slip fit if that is correct.


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## CluelessNewB (Feb 25, 2017)

I can tell you mine were a snug slip fit, at most a few light  love taps to get it on.


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## wa5cab (Feb 25, 2017)

Ron (and everyone), 

Please avoid using a link to PhotoBucket or other such to insert photos into posts here.  I know that it takes up less server space to do so but slow loading is only one of the problems that it can cause.  Another is that if you ever close your account or if the other site goes belly up, here there will be many red "X"'s, which aggravate everyone who tries to read the posts.  So use the UPLOAD A FILE button instead.


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## RonRock (Feb 25, 2017)

Thank you. I removed the Photobucket links and uploaded the files. Now I can't get the photos in the body of the thread, but they are there at least.

I'll do better next time.

Cheers,
Ron


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## MBfrontier (Feb 25, 2017)

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.




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.




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


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## RonRock (Feb 25, 2017)

Good picture!  Here is what I had trouble with.





I chucked the shaft up in my mill and turned down the portion of shaft that was causing the gear to stop with a small file. Not the best I know, but I took it slow and took many checks. It now goes together OK. Still pretty tight, but I can live with that. Better than sloppy fit.

That shaft is a tricky devil to put together with the key and gears. I used some grease to hold the key in the keyway as I slid the shaft into the gears and QCGB housing. Now I have to take it apart and clean it again for paint.


Now if I can figure out how to insert a photo in the thread. LOL


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## MBfrontier (Feb 26, 2017)

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.




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.




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


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## RonRock (Feb 26, 2017)

Sorry I was mistaken on the model number. Pretty sure mine is a 1937. I'm starting to wonder if my QCGB had been changed at some time. The tag on it shows as a 1937-2H. Which should be a wheel turret with a 2 1/4-8 spindle according to the Logan chart. Mine don't have a turret, and it has an L-OO spindle. I wonder if Scott would have any records of this SN?

How can I tell if it has hardened ways?

Beautiful paint on yours. I'm wishing I would have gone with that color. I stayed with gray because that was the original color of my lathe. I wish I would have gone with the color of yours. Baby Seal Black?


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## MBfrontier (Feb 26, 2017)

Yes, the color is Baby Seal Black. I'm going to have to purchase more paint when I paint the rest of the parts.

There is a serial number chart on the Logan Website but I think it only denotes date of manufacture. You might want to email Scott Logan and ask your questions about your lathe. He should be able to tell you what components came with your lathe at the time of manufacture and whether the ways were hardened. He's usually good about answering any emails with questions that I've sent.

Best regards.


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## RonRock (Mar 2, 2017)

Back with more questions about this referb.


I'm leaning towards replacing the bushings in the QCGB while I have it torn down. How do I size the bushings to fit the shafts after the new ones are installed? I'm guessing an adjustable reamer. Of course mine are all too big for any of these bushings.


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## CluelessNewB (Mar 2, 2017)

Yup an adjustable reamer if you need it.  IIRC I only needed to tweak one.


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## gonzo (Mar 2, 2017)

The paint color is very close to that found on Lycoming aircraft engines


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## RonRock (Mar 12, 2017)

Finally getting to do some reassembly on this  long drawn out project. Another question.

I know that they are "Oilless Bushings" but it just seems like there should be some lube on assembly. Should I be using assembly lube on the bushings and shafts? Something specific?


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## CluelessNewB (Mar 12, 2017)

I use spindle oil, specifically Mobil Velocite No 10, same as I use in all the oil cups.  

Edit:  All the oil cups that seem to have been eliminated in the later QCGB's


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## wa5cab (Mar 12, 2017)

Use the same lubricant as to be used for routine or periodic lubrication.  If that is oil, do NOT use grease to assemble with.  With Oilite bushings, grease will tend to plug the pores and prevent oil stored in the bushing from getting to the shafts.


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## RonRock (Mar 12, 2017)

Thanks guys. That makes perfect sense.




wa5cab said:


> Use the same lubricant as to be used for routine or periodic lubrication.  If that is oil, do NOT use grease to assemble with.  With Oilite bushings, grease will tend to plug the pores and prevent oil stored in the bushing from getting to the shafts.



Glad I asked. I very nearly used engine assembly lube. It's what I have on hand, and have always used it on most shafts on assembly. It did strike my mind that I had read about oilless bearings getting "fouled" during reaming so I asked. 

Good help. Although I don't have any spindle oil on hand I do need to get some ordered. 

Should be OK with motor oil for assembly, don't you think? Or do I need to hold off and get the right lube?


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## wa5cab (Mar 12, 2017)

So long as you use only single viscosity non-detergent motor oil of approximately the viscosity recommended for lubricating the gearbox, yes.  Do not use HD motor oils.  One of the characteristics of HD engine oil is to accumulate water during the cool-down cycle.  Which is boiled off to atmosphere during the next running cycle.  Machine tools hopefully don't get hot enough to do that, and especially with intermittently used hobby machines will rust.  Unless you happen to live in the middle of a desert.


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## RonRock (Mar 12, 2017)

Dang! A lot more to it than I first thought. 

Sounds like I need to slow down a bit. Not like that will be a huge issue. I started this referb in July. Then got distracted, turned into my "winter project" now nearly spring and I'll be distracted again.

I have some small parts to paint still anyway so I'll figure out the lube and hold off on assembly.

Thanks again.


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## CluelessNewB (Mar 12, 2017)

If you have a "Tractor Supply" store nearby they probably have "Traveller Non-Detergent Oil SAE 30" in quarts and 2 gallon jugs.    You may be able to find similar oil at NAPA.


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## wa5cab (Mar 12, 2017)

SAE 10 and SAE 30 plain ole ND motor oil are still readily available.  At least in Houston.  Just a few years ago, I hit just about every auto parts store within about 10 miles of home looking for SAE 20.  Every one of the places had at least a few cans of 10 and 30.  Absolutely none had 20.  At least three places that I went to the extra trouble to ask couldn't find any in their catalogs, either.  So in my case (wanting 20), I ended up using Mobile heavy medium circulating oil at ISO 68.  But the other two shouldn't be a problem.


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