Member postings for Pete Rimmer

No roller ways on an Eagle, they are definitely entry-level. my old J&S 540 had plain ways too.

The main issue with surface grinders is that the y-axis ways tend to wear rainbow-shaped. When this happens no amount of grinding the table or chuck wil produce a flat part because the table cross-travel is moving in an arc.

Steve is lucky in that 1. his wear is very minimal and 2. his y-axis is not worn in the above fashion.

Steve you're doing great so take heart and keep going. Your goal here is to make the machine perform as well as YOU can without expecting a professional-level job. For sure, it will be better just from what you have done.

Your wear on the small end of the knee, the vertical ways, is completely typical. Your print shows blue in the middle, the least worn part, more wear at the bottom of the flat ways (which is carrying the most load) and a little at the top (which is where dirt collects and grinds away the iron).

The long ways (Horizontal) are worn in the middle because whomever has used the grinder has only ever ground parts in the middle of the chuck so they have not spread out the wear. This is good for you because you now have four reference points of un-worn material.

Start by scraping the long ways on your surface plate. Before you put it on your plate put two opposite-diagonal scraping passes right down both ways to clean them up and create a good pick-up for the blue. Stone them VERY lightly to remove burrs. This will make your plate last longer you don't want to be putting an un-scraped part onto your best plate if you can help it.

Now bear in mind that you have a hugely un-balanced weight here so you will have to either use your judgement to support the heavy end with your hand or (the better way IMHO) use a smaller plate to print it and put the plate on top of the part. Just be aware that the heavy end will always put down more blue. Scrape those long ways to get a good print all along them then use a square to check the relationship with the short ways.

When you scrape the short ways, start with the section that's printing heaviest and scrape a band across both sides so you end up with two strips of blue that you then move out towards the ends. This will prevent you from scraping the ways rainbow-shaped which they already are. There's an excellent visual representation here:

**LINK**

As Kiwi Bloke said above, you can relieve the centre of a moving way so that it wears-in before it starts wearing out. Your work will be much longer lasting that way. Don't do it with a static way, obviously.

No, it would indeed require the foresight to look at the casting and realise that there was no space for a screw head. You'd have to slot the housing before drilling the fixing holes.

I have had this problem almost identical. A few swipes with a round file was all it took to remedy.

If you have a lathe with a 4-jaw and fixed steady you could easily do the work yourself. Pull the spindle and put it in the 4-jaw. Turn out a pocket in the end and press in a slug of something tough like EN24 steel. Bore it and rough turn to your taper angle by holding the back end in your 4-jaw and the front bearing running on the fixed steady.

Now re-assemble the milling spindle and tip the head over to the half-angle of the R8 taper. Clamp a toolpost on the table, line it up dead on the centre line of the spindle and use the Z handwheel to lift the knee and cut the taper. Now you'll have a R8 taper that's running perfectly true to the spindle.

That's how I did mine.

There's some more useful info in the album I have made. Have a look.

Pete.

I had one of those for about 12 years, a nice little milling machine. I got 6 collets with mine all imperial, I imagine that was the full set when it was sold new.

I was dismayed by the lack of tooling options so I removed the spindle and posted it to (the late) John Stevenson. He let a piece into the end of the spindle and machined it to accept R8 collets. After that, it was a much more useful machine.

The easy way to guarantee a good honed edge on a scraper blade is get a coarse wheel (4-600) and grind the radius dead square on the end. Then switch to your edge sharpening wheel (I use 1500 normally) and very lightly put your negative rake edges on. Because the insert is first ground square you only need to grind very lightly each time you sharpen as the cutting edge needs only be half a thou wide and gets a little bit wider each time you sharpen. This will not only save your fine grit lapping disc but help you to avoid sharpening everything BUT the edge, a common problem with novice scrapers.

Testt he blade against your thumbnail. If it digs in with only the lightest of pressure it's sharp.

The last cheapo Lidl ones I bought a couple of years back had gouges and angle grinder marks down the sliding edges. I took them back.

Here is a link that was just offered up on another forum which has a lot of detail on breech block threads. I thought I would add it in here for interest:

https://d.lib.msu.edu/etd/8139/datastream/OBJ/download/Some_engineering_features_of_a_modern_breech_mechanism.pdf

**LINK**

https://www.lambco-machinery.com/contact

No, the screwcutting ratios are driven from a gear on the end of the spindle so if it's turning, regardless of how it's made to turn, the screwcutting will work.

Your second point is totally incorrect Dave. Firstly, it would only cause a skip if there were no other teeth engaged which you'd need to be missing several in a row for that to happen. Secondly, the back gear is only a mechanism for slowing the spindle. It has no effect on the threading ratios which are all done on the end gears and gearbox if fitted.

If it's apparently working ok, doesn't knock and doesn't leave marks in the work when you're using back-gear, there's no real reason to rush into changing it. Just keep an eye out for replacement gears and bide your time, they will come along.

If you are finding that the print pattern moves about every time you scrape, the only thing that can cause that is the difference in height between the last blue pattern and the changed blue pattern is the depth of one scrape or less. If you think about it, this is a good place to be but it does mean that 1. your blue is very thin and 2. your scrapes are very shallow.

You need to increase the depth of your scrapes so that this stops happening. Once you do that your pattern will develop and you'll be able to use slightly heavier blue without it smearing.

This is also a time where having a flat stone can help a lot.

Definitely the result of over-scraping. The good thing is that you have a decent spread of blue across the length . So long as it's hinging nicely you're not far from done. As Tony says, scrape only the blue but not all of the blue. Leave9what you would consider to be) large gaps between scrapes and watch the pattern come in as if by magic.

It certainly sounds like your bench is far too high for comfort. Mine are 900mm off the floor and they could do with being lower. I am just building a lower height bench just for the purpose.

You definitely have too much blue on there but it's not too bad when you're only roughing. What you will find is that if the part has a lot of sticktion on the blued plate from too much blue it will smear and it will also print heavily around the edges of the part.

The reason Richard says to use your hand is because you will feel any grit on the plate. I rarely use my hand maily because I use an oil based blue, instead I use a rubber ink roller and it picks up a lot of this grit. I roll out a patch on a spearate plate and use that to load the working plate and replenish the roller. To get an ever spread I sometimes skew the roller so it's not rolling straight ahead but skidding and rolling. It gives a nice even coating of blue. If you roll a plate out and find it's too heavily applied, just clean the part and repeat until some of the blue is used up. For blue I use Diamant Tuschierpaste from Germany. For cleaning the parts and the plate I use Scott blue workshop towel and brake cleaner in a pump bottle.

First thing I can tell you from your pics is that your scraper is not nearly sharp enough. The scrapes are thin and long but not deep, they are skating on the surface. Next thing is that you're over-scraping each pass. However wide your scrape is, the next one must be at least that far away from the previous. From where you are at now, you want scrapes about 5mm wide and 10-12mm long with a minimum of 5mm between each one and a bit more won't hurt. go 45 degrees one way then 45 degrees the other and scrap in diagonal rows. Leave a gap between each row of at least 10mm for the above sized scrapes. If you do that and get your scraper good and sharp you'll see a good checker pattern come out right away.

You won't be disappointed with a Lamb straight edge they are easy to scrape and the casting quality is very good. I have an 18" and a 30", plus a 15" square and an unfinished 20x10" master square from him.

Steve,

You're approaching this problem backwards. Scrape the long ways straight and flat then put the square on the long ways and use it to measure the short ways' perpendicularity with the scraped long ways. For that surface it only needs to be pretty close because you will dress the wheel from the moving cross-slide. What is most imporatant is that the knee and cross table ways are nicely scraped in. That joint barely matters at all.

I think that it's most likely a gear cutting attachment. The hollow spindle holds the blank via a drawbar and tapered arbor. The vertical shaft must be fixed as it crosses axes with the rotating spindle so that's most likely a mount for a direct-indexing fixture. The gear is probably swappable with other lathe change-gears or it might be a handy integer like 48T. The 45 degree each way scale makes it handy for making bevel gears.

Can it be mounted 90-degrees rotated from it's present orientation?

Edited By Pete Rimmer on 25/09/2022 17:38:29