Thread: Turcite on steel ways. Scraping question

Ok I know we have a few new-found scraping experts here now, so I thought I'd throw a question out to you guys.

A few of us here have small mills, in the case of Bob and myself they're little Hercus mills. The biggest issue with them is lack of headroom, and that is a major problem. I've seen pictures of one that has a riser placed under the column to effectively increase the headroom. The problem with this is that the Z axis way will need to be extended. Accurately extending a way is no mean feat in my book. Here's the picture, but sadly no idea who did this Page Title

So, I was considering making up the extension as a weldment. It will easily fit in my heat treating oven, so I will stress relieve it in that after welding. However I thought I would deliberately machine the dovetail undersize and use turcite or similar on that part of the way to make scraping it in easier. I will probably dowel the dovetail on to the rest of the weldment and once in place scrate the whole way in. I haven't checked it, but I'm sure the existing way would be somewhat worn as it is.

I was wondering what you scraping experts thought of this devious plan? I doubt I'll be able to find suitable CI for the way, and scraping a steel dovetail doesn't exactly overwhelm me with enthusiasm, even though it will only be short, so I though one of the slideway materials could be the solution.

Pete

Originally Posted by Pete F

Ok I know we have a few new-found scraping experts here now, so I thought I'd throw a question out to you guys.

A few of us here have small mills, in the case of Bob and myself they're little Hercus mills. The biggest issue with them is lack of headroom, and that is a major problem. I've seen pictures of one that has a riser placed under the column to effectively increase the headroom. The problem with this is that the Z axis way will need to be extended. Accurately extending a way is no mean feat in my book. Here's the picture, but sadly no idea who did this Page Title

So, I was considering making up the extension as a weldment. It will easily fit in my heat treating oven, so I will stress relieve it in that after welding. However I thought I would deliberately machine the dovetail undersize and use turcite or similar on that part of the way to make scraping it in easier. I will probably dowel the dovetail on to the rest of the weldment and once in place scrate the whole way in. I haven't checked it, but I'm sure the existing way would be somewhat worn as it is.

I was wondering what you scraping experts thought of this devious plan? I doubt I'll be able to find suitable CI for the way, and scraping a steel dovetail doesn't exactly overwhelm me with enthusiasm, even though it will only be short, so I though one of the slideway materials could be the solution.

Pete

I have the same Hercus Model O Mill & like you & Bob have experienced the head room or space between the cutter head & the table as a big limitation with this machine.
Many times I have considered an adjustable boring head for use on this machine but it takes up too much vertical space. A while back I purchased a set of no 3 Morse taper collets that work well for holding end mills. Previously used a Clarkson chuck that also used up too much vertical spce.
Considered putting in spacer blocks & extended slide to raise the head & started to dismantle the machine. However, decided it was just too big a job considering one can purchase a new Mill with plenty of capability for a reasonable price.
Lately, I have been leaving the O Mill set up with the horizontal spindle, & using a Hercus milling attachment in the Hercus 260 lathe for end milling jobs.
Today I am modifying the milling attach to extend its capabilities in the lathe.
So to answer your question, I do not think it would be worth the time & effort to modify the Hercus Model O Mill with an extended slide.These are my thoughts on the subject.
Perhaps a bigger Mill could be a better proposition.
In my case its hard to justify the purchase, but sometimes one has to put "justification" aside in the interests of enjoyment !
regards
Bruce

Bruce, you're quite right, it terms of time and effort it would be much easier to simply go out and buy a new machine. As I may ultimately do BTW. Pretty much everything I do could be answered in this way if I stood back and looked at it; why bother, go out and buy one ... then sit on the couch watching TV and letting my brain go dead. Instead I see this as a challenging project (to get right anyway) and I feel I have the ability to do it. Why? Because I can

Pete

PS It's then another thing to place on my "to-do" list. I was panicking as I'd recently crossed a few things off it

I think it's usual to have the slippery stuff on the moving member. How would you manage the transition between the two sections? Turcite type materials must be kept free of chips. You wouldn't want a gap. I like the fabricated riser with bolt-on ways idea. But make the whole of each dovetail from cast bar.

Bryan, yes that's what I thought, hence the question. How well would it work the other way around. Remember also that this is a vertical way and only around 6-8" long. I can't see the minuscule gap as being an issue.

Yes cutting a CI round to size is an alternative I have considered, but keeping the whole lot in steel would be easier.

Pete

Originally Posted by Pete F

Bruce, you're quite right, it terms of time and effort it would be much easier to simply go out and buy a new machine. As I may ultimately do BTW. Pretty much everything I do could be answered in this way if I stood back and looked at it; why bother, go out and buy one ... then sit on the couch watching TV and letting my brain go dead. Instead I see this as a challenging project (to get right anyway) and I feel I have the ability to do it. Why? Because I can

Pete

PS It's then another thing to place on my "to-do" list. I was panicking as I'd recently crossed a few things off it

Yes, you are right, I have the same problems.
It would be a terrible thing to wake up one morning & have no projects on the go The thought of sitting on a couch & watching TV actually frightens me !
Maybe you have inspired me to do the work needed to do the modifications on the Model O mill There is never enough hours in the day.
regards
Bruce

Hi Pete,

Phil (Machtool) has a really slick technique using bronze sheeting, that might be suitable for what you want to do.

Regards
Ray

I would buy a turret mill, and raise the house to make it fit in the room...

Ray, ok, well that sounds like a good lead. Thanks.

Richard, don't worry, I have measured a Bridgeport and I think I can squeeze it in ... Just ... Maybe.

Pete and Bruce,

I have thought about making a riser a number of times, even got to the point of doing a rough sketch. My idea was a welded box frame with a cast iron dovetail extension, keyed and screw fixed to the former. One problem would be the machining, post welding, of the riser. The rough external dimensions are 240 x 255. Larger than the capacity of my shaper and either mill. Easy on the larger mill that the three of us don't have. Outside help would be required. The cast iron could simply be sawn from a larger round slice.

If you did forge ahead with a riser would you machine a new longer Z traverse screw or limit the riser height to that of full extension of the screw?

I also have a selection of 3 Morse collets augmenting my scant collection of 3C collets for when those precious millimetres count.

Back around the time that I acquired my other mill, there was a nice Cincinnati Contour Master for sale over here for a bit over 3 large. Maybe a touch larger than a Bridgeport. It appeared to be in good condition. The table was blemish free. Harnessed to the thing was a hydraulic tracing attachment which could have been removed. I often called into seller's, Bill's Machinery and deliberated.

The Schaublin took 3 days to haul off the trailer and into position. The Cincinnati would have required a crane and use of the neighbour's driveway. Then it would have required stripping and repainting. Someone had covered the original grey with beige. A bigger shed and no carport in the way and I might have bought it. I just don't have enough room.


BT

Originally Posted by Anorak Bob

If you did forge ahead with a riser would you machine a new longer Z traverse screw or limit the riser height to that of full extension of the screw?

Wouldnt you need to go to a two piece screw? (or drill a hole in your floor)

Stuart

(althought someone who types faster than me may have beaten me to it, as happened to me twice this morning lol)

I know the emphasis has been on how small these mills are Stu, but we do actually stand up to use them. I can see you have this image of us squatting while fiddling with these things.

lol Thanks BT,
The hugely tall one in the link got me all confused. I was thinking the base of the collumn was on the floor.

Stuart

O.K. It's Bryan's fault.

The little Hercus could be mounted on a benchtop requiring a hole for the Z screw. The sheet metal base was an optional accessory.

BT

Originally Posted by Anorak Bob

Outside help would be required. The cast iron could simply be sawn from a larger round slice.

If you did forge ahead with a riser would you machine a new longer Z traverse screw or limit the riser height to that of full extension of the screw?


BT

Bob, the reason I posted the question about turcite or similar is because I'd read that it was relatively soft. It got me thinking that it may be able to be trimmed down to roughly the correct dimensions using other means than the machining we normally consider here. I've also heard it to be very fast to scrape for the same reason. However even I needed to farm it out to another mill, I can't imagine it would be outrageously expensive. It would be scraped in after machining anyway.

I would leave the standard screw and sacrifice the ability to wind all the way to the very top. I'm thinking of only a 150-200 mm riser so don't see that as being a huge sacrifice.

Pete