Epoxy Bearing Materials and Method

Hello!

I gained access to the site's URL and I had an experience quite different from yours.
The site is one of those third-party stores files for download.
And my protection system was not alarmed at all. Neither the firewall or antivirus (both AVIRA) nor protectors against addware or malware.
I downloaded the file, read it and now, alarmed by your posts, submited the file downloaded to an antivirus analysis. It's clean.
I must say that its content is quite interesting.
It may be worth contacting the author to use another mechanism to provide the file.
However if anyone is interested in contacting the author directly, the contact is as follows:

John McNamara
[email protected]


Best regards
Dias Costa

Hi John

These days most users have ADSL internet connections so 40MB comes through pretty fast. I could post the low res version if any user has a dial up connection.

Edited By John McNamara on 21/04/2011 01:16:46

Edited By John McNamara on 21/04/2011 01:18:23

Hi All

Gee computers can be such fun! A lot of discussion has been had with Mediafire about why Norton objected. I guess we will never know. In order to avoid any annoying third party adds popping up I converted my subscription to a paid one, this means that the third party advertisements do not show. Only the main web page.

Attached is a powerpoint I did for epoxy bearing material
It was presented in Melbourne Australia

A piece of threaded rod with epoxy nut decribed:

I posted a copy of the file here (with high resolution images) 41mb:

http://www.mediafire.com/file/ttxoomm025htxeu/Epoxy%20Bearing%20-%20MEW.ppt

 

Also a copy with low resolution images 4.5mb:

http://www.mediafire.com/file/022r26w92qxcn10/Epoxy_Bearing_-_Compact.ppt

 

Cheers

 

John

 

Looks like its done already  

Edited By John McNamara on 21/04/2011 14:19:31

Hi John,

Just downloaded your PP file, looks very interesting to me, thank you.

I only use the included AV with Win 8.1, I actually suspect all the others as being the orinators, to gain profit from those whom believe them...

John,

I've just downloaded the "compact" version onto the [first generation] iPad and saved it into GoodReader.

... about thirty seconds for the whole operation.

Great job, thank you.

MichaelG.

Edited By Michael Gilligan on 27/04/2014 08:21:04

Hi Michael
Hi Bernard

It is great to get some feedback. The file has been downloaded many thousands of times. Unfortunately not everyone is a courteous. I guess that is the nature of the internet.

The thread and nut test piece as shown in the Power point has never loosened up. It was only a test piece so it has never seen duty in a machine , however many people have played with it twisting it back and forth....

My lathe saddle is still running on that material between it and the bed without a hitch, the saddle must weigh over 150 KG I have to crane it off. Just for interests sake when I get some free time I am going to remove the saddle and check the actual condition of the material. its been a few years since I did it.

My Heidenreich and Harbeck 21 RO Lathe is similar to but a little younger than this one
**LINK**

Although I have not tried it I do not believe Epoxy composite bearings will work well for high rotating or sliding speed applications.

They work very well for machine tool slide ways. (some new machines come with them) the material is also very good for bedding and grouting parts together after precision aligning them.

Regards
John

John McNamara:

I found a good deal of interest in this revived thread, not least in your presentation once I was able to view it!

I dumped MS Office some years ago and currently use the ("free" Document Foundation suite. In retaliation (?) MS Windows Firewall blocked the Document Foundation presentation program from displaying your low-res images so I took a hint from Michael Gilligan and viewed them satisfactorily on my (Samsung) tablet via the bundled Polaris office suite.

It was very encouraging to see your splendid lathe rehabilitated through the magic of epoxy resin.

Your last slide asked for questions. Was there any discussion of slideway lubrication and whether it is needed with this method?

Hello EGA

Yes normal lubrication is required. Epoxy being resistant to most (Nearly all) chemicals once it is cured, is not affected by mineral based lubricating oils or water based soluble oil if you use it. If you study the images in the power point you will see I reinstated the original oil pockets in the epoxy material with a die grinder. The lathe has a small plunger pump that is operated by the saddle traverse handle to provide lubrication to the ways.

The lathe I restored was very worn. Once the ways were ground the and the saddle raised to the correct height there was quite a large gap nearly 2mm between the saddle vees and the bed vees. In this case I did not grind any more material from the underside of the saddle I did use a wire wheel to deglaze and clean the vees under the saddle, alternating with thinners and methylated spirit to remove as much oil as possible from the cast iron for good adhesion before applying the bearing material.

When I got the lathe the backlash on the saddle hand wheel was about a quarter of a turn. Once raised to the correct height it was minimal I also checked the leadscrew height and lateral position at the same time and it was no longer bowed. This always has to be considered if you are restoring a lathe bed. If you decide to scrape the saddle to match a reground bed for a metal to metal line contact you have to machine the top of the apron or the underside of the saddle to correct the lead screw misalignment, and much harder... Correct the alignment between the rack and pinion that drives the saddle. Using epoxy bearing material you only need to jack it into position until all misalignment is corrected. The epoxy is replacing all the worn away material.

The jacks are the key.... You can take as long as you like to get the positioning right before you place the material, I set up the cross slide for normal running before adjusting the jacks, this allowed me to adjust the saddle relationship to the spindle axis as well.

After the epoxy was set the shrinkage across the tiny gap between the bed and the saddle is infinitesimal. I did not need to scrape the saddle in after the epoxy was set.

Regards
John

Edited By John McNamara on 28/04/2014 02:04:29

Hi All

Using the epoxy method will not correct for a worn saddle rack and pinion drive.. doing so would put the leadscrew out of alignment. I was lucky the rack and pinion are hardened and showed negligible wear.

I tried to edit the post and insert this (Yes editing was available at the time) but the editor would not do it. there is a repeatable bug in the forum software.... if you edit a post more than once the second edit may or may not work. the workaround is to log completely out of the forum then log back again, and that of course subjects you to the interminable wait that this site; (unlike almost all the other engineering sites I visit....) gives you.

Regards
John