Hendey lathe bed grinding

Hello all,
I thought I’d post some follow-up to my Hendey lathe bed refurb project.
As you may remember I was originally planning to scrap the center of the bed and use the “Beckley23” method to fix the carriage ways.
After some torturous work, I came to the conclusion that I probably would be 100 before I finished that plan, so I decided to get the bed professionally ground.

Scroll ahead a couple of weeks,
I had some time off owing from work, so I figured just as well now as ever, and contacted Kellar Machine Rebuild (KMR) in Kingston Ontario about getting the work done.
The owner, Mike Kellar told me that he could fit me in toward the end of the week and, if necessary over the weekend.
As shipping was going to be an issue I decided to load the bed in my truck and drive the 8hrs and wait for the job to be done, then haul it home. (This was actually cheaper than shipping)

On last Wednesday afternoon ( March 9,2011) I arrived at KMR and met Mike and his nephew Jason Kellar, who is his helper/trainee. I got the tour of the shop and we discussed how things might happen.
We unloaded the lathe bed and got to work, BUT not on my project.
Mike told me that the bed had to warm up until at least the next morning, so I got to watch them grind the ways on a milling machine table that was set up on the big WMW slideway grinding machine. They had set up the saddle next to it and were going to grind the slide in the same setup ( sorry I didn’t get a picture)

As a side bar to all this, when I spoke to Mike on the phone, I commented about scraping the bed. “You know how to scrape?” he says. Yes I knew a little about it. So he asked me to bring some “stuff” and teach Jason some scraping.
This was a bonus as it would give me something to do while I waited for the bed, and allow me the opportunity to observe the work being done on my project.

Anyway, I put on the overalls and Jason and I got to scraping while Mike worked on the mill table. The scraping lessons progressed intermittently through out the whole time I was there.

Thursday morning I showed up at KMR at about 8:30 to find the guys still doing stuff other than my lathe bed. (wait in line Pete ;-)) But that was OK as I was able to watch them grind some parts for a Colchester that a customer had “fixed” using a magnetic chuck on a surface grinder. What a mess that turned out to be. It will be nice once KMR is done with it, but that owner didn’t do his machine any favors.

Around 10:30 we started loading the Hendey bed on the machine.



Mike set it up on 3 points and leveled it with a Starrett master precision level. He then set up a couple of dial indicators and adjusted the bed straight with the grinder to near 0-0.

This process took the best part of 1.5 hrs.
After lunch Mike started by grinding the tops of the carriage ways. I asked him to make sure that they turned out as level as possible as I wanted to use it to level the machine later.

He then set up to grind the Headstock seat/tailstock slide. This is the one I had partially scraped. It turned out to be pretty good, within a couple of tenths, which was pretty gratifying. He had to take another couple of thou off the remove all the damage.
Work continued until quitting time and we adjourned for the evening.

Next morning work started on the front carriage slide.
I was most interested in this as this one had the most wear. I had measured it as being between .007-.010” worn.
WELL…. By the time Mike removed the damage and got it straight he had removed nearly .040”.

look closely just to the left of the grinding wheel and you may be able to see the damage

This was much worse than I feared! The rest of the bed was not near as bad, although there was some twist that made for a little extra work.
All in all the grinding took close to 14 hours. Mike ground 12 surfaces. All are now straight and parallel within .0001” as they were all ground on the same setup.
Mike took particular care to ensure that the horizontal surfaces were level and that everything had a nice fine finish. He also ground a couple of surfaces that I hadn’t considered, like the bottom of the tailstock slide, and the bottom of the rear carriage way as these have parts that clamp up on them.

I have to say that I am very pleased by the service I received! Mike’s willingness to accommodate my schedule and his patience and tact in dealing with my lack of knowledge and preconceived ideas on how I though this should turn out is to be commended.
I paid approximately $1800.00 plus taxes. This was about equal to another quote I'd gotten and $600 cheaper than the big shop in Toronto.

Considering the amount of work done I think this is good value. It would have been an impossible chore to do by hand, and with every pass of the grinder I had more and more admiration for Harry Bloom!

Great post, Pete; thanks for taking and showing the pictures!

Is that a CBN wheel?
Did they comment about why their (apparent) preference for grinding dry?

smt

Stephen,
yes the wheels are CBN. Mike Kellar told me that they grind cooler, and last longer. The lack of coolant is apparently due to the cool grinding characteristics of the wheels, and a whole lot less mess.
From what I observed they grind pretty slowly anyway, and the coolant probably wouldn't speed up the process much. Mike was constantly checking to insure that the temperature didn't rise on the bed.
The grinder is a dedicated purpose built machine by WMW (German) and it has a hydrostatic slide mechanism. All the ways on it are covered and the workpiece is supported on "floor plates" like I have seen on big boring mills. I believe he told me that he can grind 24 ft.
The dust collection system is built in to the machine.

Pete

Pete

Very educational . Its the first time I've ever saw a lathe being ground.

Thanks for posting pictures.
Be sure to post a few when you get the machine back together.

Hal

.040 is a shitload to grind off, not surprised it took so long. But now you have a good candidate for Moglice under the saddle.

Great post and very educational.. I see now why way grinding is expensive to get done.. it takes a long time to do to get it right..

Pete

How much do they grind off in a pass ,.001 ?

Hal

Material removed per pass was less than .001"
I don't know exactly how much, but it was pretty conservative, and they frequently let the machine nearly "spark-out" before feeding in.
They were very concerned about heat!

Pete

.040" ground off, you did right getting the bed ground. Like Russ said, that's a lot of scraping, and I would have done the same thing. You're going to have a good lathe when you get done, and it does get easier after the bed is done.
Harry

sounds like things went will with Kellar. I've a couple I'm planning on taking there.

Pete maybe you or one of they guys can help me out what whats a mystery to me in the process.....

A great many lathes are of the style where the headstock registers on a V way to ensure V ways and spindle axis are aligned. Now I get that the grinding, if done well, will ensure the ways are well aligned to each other. However i expect is difficult to impossible to ensure that there is the exact same height and angles etc between the way elements. Stated another way, I'm thinking the lathe headstock would not perfectly blue out against the freshly ground ways.

Is this the case and if so what do you do about it? Scrape the headstock into the bed?.....then how do you ensure scraping the V keeps it dead onto the spindle axis?

thanks

Mcgyver said:

Is this the case and if so what do you do about it? Scrape the headstock into the bed?.....then how do you ensure scraping the V keeps it dead onto the spindle axis?

Click to expand...

As you say you scrape the headstock to the ways, using a test bar in the spindle. The test bar can be anything round with a taper in the end or even Thompson rod in a 4-jaw. I held my 10EE headstock with something of a spreader bar on an engine hoist for test fitting:



As you can see there's a wooden buffer under the headstock where it's resting. Really, in my case all I really had to do was to scrape for fit, the alignment was pretty good. Another way is to put little pads of way material to support things, scrape for alignment on them then to use an epoxy resin similar to Moglice to fill in between on the final fitting.

rke[pler said:

As you say you scrape the headstock to the ways, using a test bar in the spindle. The test bar can be anything round with a taper in the end or even Thompson rod in a 4-jaw. I held my 10EE headstock with something of a spreader bar on an engine hoist for test fitting:
.

Click to expand...

thanks Russ. I guess i'm not understand the test bar part....for example Thomson rod in a four jaw could be introducing all kinds of error other than misalignment of the V and spindle...can you give more detail/commentary on the use/set up of the test bar; chuck to spindle, jaws. In your pic is that taper section the sling is on part of the test bar set up, and I'm not following when you say can be anything with a taper - as in headstock spindle taper I must be dense this morning.

Mcgyver said:

thanks Russ. I guess i'm not understand the test bar part....for example Thomson rod in a four jaw could be introducing all kinds of error other than misalignment of the V and spindle...can you give more detail/commentary on the use/set up of the test bar; chuck to spindle, jaws. In your pic is that taper section the sling is on part of the test bar set up, and I'm not following when you say can be anything with a taper - as in headstock spindle taper I must be dense this morning.

Click to expand...

Sorry for glossing over that - I'm still on my first cup of coffee and only marginally awake.

Yes, the taper would be for the spindle. What you want is something mounted to the spindle that is round and can rotate in the spindle. You scrape something to the bed and use that to traverse the bed (I started with the saddle and ended up using the tailstock base) with an indicator on the rod. At the places you measure you rotate the rod for a min/max reading and take the average. Measure the top and front of the rod and you have a trend for both vertical and horizontal - and if the bed is flat it tells you which way the headstock is pointing. Here's a link to one of Harry's threads showing the setup:

http://www.practicalmachinist.com/vb/monarch-lathes/wreck-update-146913/index3.html#post1202860

There are some technical details - like the rod will sag at the far end - but in the main you can use this with anything round. If it's not the same diameter you can correct for the changes in diameter on the measurements by adding in the change in radius for each position for the trend line. It's probably easiest to use a rod that mounts in the spindle taper but a chunk of Thompson rod in a 4-jaw works about as well.

_Machine Tool Reconditioning_ by Connelly is the standard for this, you should have a copy to read a few times before starting this - it'll keep you from the blind alleys that you're otherwise likely to travel (like making sure that the bed is mated to the base without warping before scraping in the headstock, etc.). I didn't understand a lot of it on my first pass, misunderstood more in my second pass, but after my first refit and 4th or 5th reading think I'm getting the gist of it.

.040 ground off (assuming that measurement was taken perpendicular to each v-way surface, that much drops the cross feed gear axis & half nuts pretty low w/ respect to the lead screw and any feed rods or gears. How do you get by that?

I suppose you could remove material from the top of the apron to to get the half-nuts in line w/ lead screw. But that doesn't help w/ the cross feed gear(s) alignment if I'm envisioning it correctly.

How do you deal w/ those alignment issues in a rebuild?

mark

morsetaper2 said:

How do you deal w/ those alignment issues in a rebuild?

Click to expand...

You either lower the lead screw and feed rods & rack (and whatever else is there) or raise the saddle back to the appropriate height. The saddle height and alignment can be done a couple of different ways - one is to glue Turcite, Multifil or some other way material to the saddle ways then rescrape things back in (look in Harry's "Wreck Update" sticky thread), the other way that I went with was to use the bed ways to form Moglice into new fill for the saddle ways:

http://www.practicalmachinist.com/vb/monarch-lathes/all-milled-up-ready-moglice-98625/#post311408

This method uses the newly ground bed as a 'master' to form the Moglice putty into way material, avoiding most of the scraping. Some of the preceeding steps - like milling the saddle ways to provide tooth, etc. aren't in that thread but can be explained in other threads.

If someone was to use this they need to refit the cross slide and saddle cross slide ways to use to reference the spindle axis as you need the cross slide travel to be flat across the bed and perpendicular to the spindle axis while keeping the apron height correct and level for it's operation. I didn't feel like I could scrape the saddle into those references while holding the apron height - but I could tweak screws around until I had all the axis correct.

Really, you want to read the thread here:

http://www.practicalmachinist.com/vb/monarch-lathes/wreck-update-146913/

Harry's laid most of what you need to think about in that thread.

After looking at the Hendey pics, the good news is that it looks like the headstock is not mounted on the ways a la Monarch. As Russ said, now you just have to raise the carriage back up to original height (Moglice would be my choice also) and you're good to go....maybe.

daryl bane said:

After looking at the Hendey pics, the good news is that it looks like the headstock is not mounted on the ways a la Monarch. As Russ said, now you just have to raise the carriage back up to original height (Moglice would be my choice also) and you're good to go....maybe.

Click to expand...

Yeah, different set of problems here than the Monarch. On mine I had to trim .007" from the top of the gearbox cover (the 1/4 round thingy) and (if I recall) the top of the rear cover. There was also a little spacer that screwed into the top of the ways in the back that had to be ground down some - I think it's just something to block swarf from going too far back.

On this I think the real work is going to be the tailstock. Even if the grinding went straight down there's usually some fitting from the wear in the sliding part of the base. By the time that's fit to the newly ground bed it's going to be down a significant amount. On the 10EE you have to modify the access to the screws used to shift the tailstock on it's base after you shim the top casting up more than a few thousandths, maybe the Hendey has the screws bearing differently so it can deal with a honkin' thick shim.

Not to hijack the OP, but you may remember(went back and you mentioned this in a earlier post, duh) I went a different way and used a Moglice formulation w/o the slippery stuff. I jigged the headstock and set it down on the Moglice. I was able to really dial it in to the ways. The idea of taking the headstock off and on, upside down to scrape it , maybe a hundred times made me nauseous. As far as the tailstock is concerned I seem to be the only one that has had success using Moglice on the bottom. I could barely move it, as the contact was almost a "wring" to the ways.

I know this is an old thread but I ran across this listing for a WMW way grinder and I think it is the same one in this thread. Did Kellar close down?

WMW Hydrostatic Way Grinder Manufacturers Suppliers Exporters

WOW-I cant believe you got somebody to pay $1,800 for this kind of work on a small machine.

Don't get me wrong-they got every penny worth of it. This stuff takes time and money.

I quoted another forum member who is local to me to grind bed ways, I cant remember how many surfaces but it was not all of them. I quoted $500. This was my cost and I had open time on my machine.

They said for what they had into the machine they could not justify it.

I understood that.