What's new
What's new

Vintage Bertram Lathe - Use and Restoration & Help Required

Dustnorm

Plastic
Joined
Sep 14, 2018
Hi Everyone,

I purchased this lathe back in March this year. It is much larger than I originally wanted, but it was $400 and was working when I arrived to have a look. I was looking for something that would fit into my small garage workshop... but I didn't hesitate to take it home with my in my Ford Ranger (very slowly). The goal is to have a machine that would help me to maintain some of my other vintage machines, like my Bandsaw and Drill press, as well as to use for other woodworking and metalworking projects.

I was told that the father of the man I purchased this from used to work in a machine shop, and he was given or purchased this lathe when he retired. The son inherited the lathe and he used it rarely. He wanted to sell because it took up so much space in his shop and wasn't being used. I was the 2nd person to look at the lathe after only having being posted for 1 day. the first person didn't have the space for such a large machine. It is noted as a 12 x 32, however it measured as 14 x 32, but my measurements are exact

I did an initial cleaning to remove as much grease and oil as I could, and now I am working on a complete restoration, including addressing any backlash in the cross-feed and reviewing the gearing for threading.

I am in a bit of trouble with the gearing, I think the machine has been setup for removing material and I have no manuals or information from the previous owner to know how this should be setup. I have attached an image with the chart and the number of teeth on each gear and I figured someone else with more experience may be able to help. There are three more gears which came with the machine in addition to those noted in the picture. (44T, 45T, 56T)

Any help would be appreciated. I'll by updating the pics as I make progress on the restoration.

Thanks,

Mike
 

Attachments

  • Bertram 3 Jaw Chuck.jpg
    Bertram 3 Jaw Chuck.jpg
    98 KB · Views: 540
  • Bertram Overall.jpg
    Bertram Overall.jpg
    99.4 KB · Views: 955
  • Bertram Headtock Spndle Closeup.jpg
    Bertram Headtock Spndle Closeup.jpg
    99.7 KB · Views: 847
  • Bertram Gearing.jpg
    Bertram Gearing.jpg
    100.5 KB · Views: 492
  • Bertram Carriage.jpg
    Bertram Carriage.jpg
    98.9 KB · Views: 498
Additional Photos For Bertram Lathe

Hi again,

Here are some additional photos for reference. Some parts are off of the machine because I an stripping the paint and cleaning.

Does anyone know how old this machine is?

Thanks,

Mike
 

Attachments

  • Bertram Motor & Gearbox.jpg
    Bertram Motor & Gearbox.jpg
    96.4 KB · Views: 298
  • Bertram Leadscrew Threads.jpg
    Bertram Leadscrew Threads.jpg
    97.9 KB · Views: 236
  • Bertram Made in Dundas.jpg
    Bertram Made in Dundas.jpg
    99.3 KB · Views: 280
  • Bertram Gear Closeup.jpg
    Bertram Gear Closeup.jpg
    97.6 KB · Views: 284
  • Bertram Tailstock.jpg
    Bertram Tailstock.jpg
    99.1 KB · Views: 367
Some need to know stuff

Lead screw is for threading - for this screw to move the carriage, you have to engage the HALF NUTS - a lever on the apron.

Feed rod, below lead screw is for FEEDING - both longitudinally and cross. The gearing involved is IN THE APRON and has nothing to do with change gears. In fact, when the feed rod is BELT DRIVEN, there is hardly any change gears involved at all - if any. For this ROD to move the carriage or cross slide, you have to engage the appropriate feed CLUTCH on the apron

Chart shows but four choices of stud gear 80, 60, 40 and 20. It appears the 30 gear is on the stud "position" at this time - not an entry on the chart. If the adjacent 20 can take its place, you would be set up to cut 17 threads per inch - since you have the 68 in the SCREW gear position. The STUD gear position - as can be seen - is the pivot point for the reversing lever

The idler gears are just that - their tooth count has nothing to do with what is being cut for threads. Their ONLY function is to allow the STUD gear to drive the SCREW gear

Since the lead screw appears to be .200" pitch, that makes it 5 threads per inch. The 20 and 68 have the right math to confirm this. 68 divided by 20 = 3.4. .200 pitch divided by 3.4 = .058824", the reciprocal of 17
 
Thanks, I had a feeling something was off. I thought I was missing some gears, so it may be necessary to borrow the gear(s) from the cross-feed rod. This lathe is very old and passed through a few hands of people who do not know the correct setups. It is very easy for someone to swap gears out and lose track of what they've done. When I'm further along with the restoration I will make a diagram explaining the proper positions and make/buy and missing gears.

There were some hidden gears, so I've given a better view. The 20 and 24 gears are both keyed, so they both spin, however the 24 was not engaged in any gears when I purchased the machine.

Thanks,

Mike
 

Attachments

  • Bertram Gearing Detailed.jpg
    Bertram Gearing Detailed.jpg
    102.1 KB · Views: 333
When time allows, get the belt drive and its pulley off so you (and us) can see better what is happening.
Every time someone set this up with a different STUD gear, they had to have the belt business off
 
Pulley removed for clarity

I had gone too far before I read your post, I've been dismantling the machine to clean all existing paint off and repaint. None the less, the image shows the 24T and the 20T gears, both of which are keyed. This is a 1" spindle, so there is hardly any "meat" for the 20T, especially considering the key slot.

Anyway, I have been experimenting with the math and I believe I have a better handle on it. I am looking to match the pitch of the lead-screw and also for a 6 TPI for the spindle thread. so 20/20 for the 5 TPI and 20/24 for the 6 TPI. Having little to no experience in the past with gearing, it figured all gears had an impact, but that only seems to apply in compound gearing.

Other lathes have a large idler gear, this one doesn't, what is the purpose of the large gear? Smoother operation possibly, or maybe compound gearing? If necessary, I can find one or make one. The other Bertram #5 has approx 110T from the photos I have seen.

Thanks once again.
 

Attachments

  • Bertram Pulley Removed.jpg
    Bertram Pulley Removed.jpg
    92.1 KB · Views: 240
In the simplest possible scenario, there will be a such and such stud gear and there will be a such and such screw gear and there will be a single idler enabling the stud to drive the screw. These naturally will all be in the same plane. I would imagine the lathe is built to accommodate two planes, an outer and inner, which enables compound gearing, the idler then becoming very important tooth count wise and occupying both planes.

Your chart says says 40 and 40 for 5 TPI - suggesting idler isn't big enough to work 20 and 20

Big gears enable - apart from threading operations - slower feeds on lathes not having belt drive feeds with their own gearing

Thumbnail is one of those simplest set ups with a big stud gear driving a small screw gear with a good sized idler

Additional thumbnails illustrate the TWO PLANES when compounding and show how the needed spacers can be shifted around. Giant "idler" is metric transposing. 127 teeth outer and 100 inner (or vice versa) - providing one of the ratios (1.27 to 1 ) used in metric transposing. Example: 1.27 divided into your lead screw pitch of .200" = 4 mm pitch when the lathe is set up to do 5 TPI
 

Attachments

  • End Gearing.jpg
    End Gearing.jpg
    21.1 KB · Views: 107
  • Simple and Compounded.jpg
    Simple and Compounded.jpg
    64.5 KB · Views: 144
  • Translating Gears.jpg
    Translating Gears.jpg
    21.5 KB · Views: 120
Last edited:
I'd really like to set it back to it's original gearing, but it until I spend some time researching so I have a good understanding I won't modify or buy anything. From what I can tell these gears are a 14 pitch (68+2/5" Dia) = 14, which makes them not so common, I may either have to make special replacements or buy an entire new set and machine the bores or hubs as required. For now, I'm happy to do some testing for internal threading for the spindle.

Blown up the gears measure at a 20deg pressure angle on average.

I'll post some progress images on the restoration process, starting to make some headway on it.

Thanks,

Mike
 

Attachments

  • 20180918_184325.jpg
    20180918_184325.jpg
    99.8 KB · Views: 92
If you go back and read through Brian's thread on his old Bertram that was quite similar to yours .
Its quite long but there are lots of pictures there to show what you might expect yours to look like as it comes apart.
https://www.practicalmachinist.com/...s-lathe-saved-230971/?highlight=Bertram+lathe
You can see the set of gears that he had and also pictures of the back of the apron that shows the setup of the feed shaft gearing for longitudinal and cross feeds as well as the half nuts .
Maybe Brian will come along and add something when he gets a chance.
Regards,
Jim

P.S.
If you can find a suitable idler to fit maybe you Could use a 40 / 48 combination giving the same ratio as 20/24 to get you 6 threads ?

Jim
 
I have read through a little of his original post, his is the closest machine to mine that I have seen. Bertram made a #5 lathe which was there smallest at a mere 1200lbs. They really have no photos or documentation on this lathe that I could find.

The best part of this lathe for me is that I live only 20 minutes from Dundas, and used to work about 1 block from where the factory operated. The building I worked in was also historical and produced wooden finger-jointed telephone boxes... apparently.

I think I'd be happier with the larger gears as you suggest, the 20T with a 1" bore is just way too thin to last. In taking off and cleaning all of the gears tonight, there are so few that match and the thicknesses also vary, so It looks like a fair amount have been replaced over time, it would be fantastic to have a matching set, but that may be costly. I'm sure with some ingenuity I could setup a jig to produce my own gears using the lathe itself, but that it a fair amount of time and the final product may not be to the quality standard needed.

More cleanup tonight... 100+ years of oil does not come off so easily.
 
I had a look, that is quite a set. I wonder if it would it cause a problem if the PA is different? I believe mine are 20 deg, at slow speeds it may not cause an issue.
 
I had a look, that is quite a set. I wonder if it would it cause a problem if the PA is different? I believe mine are 20 deg, at slow speeds it may not cause an issue.


:D What is more or equally important is that they are NOT 14DP - you would need to change over to their 16 DP in the system
 
New discovery, I took more measurements and found that all of the gearing prior to the 20T are 12P. So there is a mixture of gear DPs on this lathe. It didn't occur to me that they could be different.
Some of the 14 DP gears look very old, but they could be replacements as well I suppose, or another scenario is that the original lathe used a variation. Maybe the size of the lathe restricted the size of the gears, or they wanted to use smaller castings for the gears.

I have attached examples of two newer gears on the machine just after the spindle gear.

I had been using break cleaner, switched to Paint Thinner today, and the cleaning process became a lot easier and less costly. I had no clue paint-thinner could thin these types of oil.

In taking apart the carriage some good news is that the gears are in good condition with very little wear, that includes the ways (I am a lucky guy) Saying that I remembered that he emphasized to me, "Oil in all of the holes each time you run it".

Have to run guys,

Some photos to come.
 

Attachments

  • Boston GD27.JPG
    Boston GD27.JPG
    62.5 KB · Views: 92
  • Boston ND30.JPG
    Boston ND30.JPG
    76 KB · Views: 101
Fine to have some other DP spindle down to gear behind stud gear (the 30) - they don't get changed:D

Its the ones that get taken off and put on that all have to be one DP or another
 
I'm not 100% sure, I was measuring worn gears, so it is possible the angle is not 20deg. I'll put some more work into it in about a week after I have the lathe re-painted and back in one piece. My trusty Ford Ranger did take the loading by the way, but it was close, and I was looking at the hood the entire way home, a very slow drive. Probably best on a trailer if there is a next time.

Thanks for your help guys. :)
 
I decided to rent a pressure washer to remove the paint, using paint stripper worked, but was very time consuming and very potent smelling. The wire wheel didn't seem to do a great job on this old paint. For the most part, the pressure washer worked well, there were a few spots of paint that were stubborn, so I've been taking an old chisel to those spots (with a respirator on) I'm working on the assumption that this is lead paint, so the pressure washer seemed a better idea to remove most of the paint. Here are a few photos of the color, the lathe was possibly black, then green, then grey in some spots. I chose safety green, which is similar to the spots of green I could find on the back of the doors, or the underside of the tailstock locking plate.

I have so little space in my home shop, so my plan is to assemble the frame and then gain some space and finish cleaning up and painting all of the small parts.

I'm shooting to have the frame back together this weekend, I'd like the paint to cure a little before going together so the parts don't stick.

During the cleaning, I discovered a few more oil holes which were plugged, so they have been cleared now, all of the grime made it really hard to identify these.

I was thinking black for the lettering on the brand name, any other suggestions?

Thanks,

Mike
 

Attachments

  • 20180924_214018.jpg
    20180924_214018.jpg
    92.6 KB · Views: 132
  • 20180924_214055.jpg
    20180924_214055.jpg
    98.1 KB · Views: 136
  • 20180924_214027.jpg
    20180924_214027.jpg
    95.8 KB · Views: 111
Hi Guys,

I'm painting the last part of the main frame tonight, lots of work to clean all of these parts, but it's looking pretty good (if you like green). I'm curious about brass shims, there were no shims when I took the machine apart, though I did find that if I torqued down the nuts to lock the spindle, they were too tight, do I need to shim and if so where do I buy this stuff? I'd also like to put shim stock between other wear parts on the lathe. Any ideas?

This weekend the legs will go back on and I'll be bolting some of the other smaller components to it. Good to give the paint some time to cure before re-assembly I would think.

Thanks a lot.

Mike
 








 
Back
Top