Thread: hercus bed regrinds

I have arranged the regrinding of batches of Hercus beds and have found a professional company of long standing that will do the job. What I propose is an exchange bed service which will reduce the cost of regrinds to just over $300, give or take a few dollars. This will cut the price to a level most can afford and still leave a little to help run the AMH website. If any one wants to take advantage of this service and need to know any more, you should contact me direct on 0438466008.
Regrinding of your existing bed may also be a possibilty, so long as you can fit in with the work schedule.
Mal
Australian Metalworking Hobbyist.com.au

That is a great price, Mal!
Would they be interested in doing a similar sized Premo for that?
I should measure the vee angles, etc...
regs,
AndrewOC

HI Andrew,
Sorry only Hercus 9's and 260's at the moment, I don't have sufficient stock of any other kind of bed. You need to have 20 or so to make it work.
Mal

There will be a batch going in for grinding in about 3 weeks or so, anyone who wants their bed reground will need to arrange for it to be with me in that time frame. They will need to have their feet and racks removed and given a thorough cleaning. Full payment (around $330) will be expected just prior to completion. I am going to have to pay for the extra units if there aren't enough of you to make up the numbers, so get organised please.
For those are going to ask, the exact processing time is not known until they are dropped off. I will inform all participants when I am given a date.
Mal

Mal, after a bed regrind, what other issues have to be addressed in terms of alignment?

I'm sure the head stock and tail stock will be ok, that leaves the saddle. How is the relationship between the lead screw and the saddle adjusted?

What needs to be done with the rack?

Ken

Hi Ken,
I haven't had to do one myself so this is what I think should happen. The saddle will obviously have the same wear marks that appeared on the pre-ground bed, this being the case, the saddle ways will need to scrapped flat again to give full bed contact. Considering the size of these surfaces, it should be a relatively minor scrapping exercise. Depending on the amount taken off each component, the apron and leadscrew bed mountings will need shiming to bring the leadscrew and rack back into line and crossfeed gear in proper line with the crosslide screw(in the case of an A or B model). C models having no drive gear on the crosslide screw don't have the same problem. In the very worst cases, it may be necessary to remove some saddle casting material to clear the bed flats.
It is my hope that the grinding company will be able to note, on the bed, the amount of material they have had to remove, thereby making the shimming a little easier. Measuring the height of the saddle before and after scrapping should give the rest. I have a few machines to restore after the first batch is done so will have a better working knowledge after that. Might even make a video of the process. One of the things that will have to be added to the workshop manual, if I ever get it finished (which is doubtful).
I don't claim to know everything, so am open to anyone who has done this themselves and can correct anything I have got wrong or omitted.
Mal

Headstock will need to be refitted to the bed, this means alignment in both horizontal and vertical.

Saddle will need to be refitted, aligning the cross slide with the spindle. Middle third of the saddle is relieved slightly so it does not bare on the bed when new.

Tailstock will need to be refitted in both the vertical and horizontal plane.

For something small like a Hercus it is not a massive undertaking, but you will need scraping skills and some specialised tooling you could make yourself.

Originally Posted by .RC.

Headstock will need to be refitted to the bed, this means alignment in both horizontal and vertical.

Saddle will need to be refitted, aligning the cross slide with the spindle. Middle third of the saddle is relieved slightly so it does not bare on the bed when new.

Tailstock will need to be refitted in both the vertical and horizontal plane.

For something small like a Hercus it is not a massive undertaking, but you will need scraping skills and some specialised tooling you could make yourself.

Maybe I'm missing something but why would you need to play with the headstock base and tailstock base, if both the surfaces, vee's and flat go down by the same amount vertically, won't that just be maintaining the same plane as the original. I would think playing with the original scrapping of the headstock would be a very bad idea.

If it maintained the same plane as original wouldn't that mean that nothing was done.

Would I be able to reset this if required in a back yard shed or would I require a climate controlled environment.

What backyard skills would be needed to make my lathe work again.

When I first spoke to the grinding company to organise this arrangement, I asked how much could be expected to be ground from the bed in the worst case, they told me the worst he had ever had to take off was about 0.010" and most where closer to 0.004 or even less. So the amount of packing needed to return all the relationship back to normal should be minimal. In fact one owner I talked to a while back told me he just reassembled the lathe without doing anything else and it ran beautifully.
When I put this batch in, I will make a point of including a bed with extremely bad wear which I will rebuild to see what problems arise. I would be interested in hearing from people who actually own a Hercus this has been done to and what problems they may have encountered.

Originally Posted by allterrain50

Maybe I'm missing something but why would you need to play with the headstock base and tailstock base, if both the surfaces, vee's and flat go down by the same amount vertically, won't that just be maintaining the same plane as the original. I would think playing with the original scrapping of the headstock would be a very bad idea.

All depends on how well the V way is kept to the original angle and if the height difference between V and flat is kept the same. Probably will not matter too much on a Hercus though.

It does not have to be done, but it you wanted the absolute best results it has to be at least checked. It is not going to make your lathe any more valuable whether you scrape the headstock and tailstock in after bed grinding or not. The tailstock on one of my Hercus's never even had the same serial number and it never affected performance. And in most cases you probably would not be able to tell the difference.

I am pretty sure I know who is going to do the grinding and I will add that they are one of the most honest businesses I have dealt with. If any problems arise I know they will not tell you to go away.

Originally Posted by allterrain50

When I first spoke to the grinding company to organise this arrangement, I asked how much could be expected to be ground from the bed in the worst case, they told me the worst he had ever had to take off was about 0.010" and most where closer to 0.004 or even less. So the amount of packing needed to return all the relationship back to normal should be minimal. In fact one owner I talked to a while back told me he just reassembled the lathe without doing anything else and it ran beautifully.
When I put this batch in, I will make a point of including a bed with extremely bad wear which I will rebuild to see what problems arise. I would be interested in hearing from people who actually own a Hercus this has been done to and what problems they may have encountered.

I had absolutely no problems with reassembly after having the bed ground, I reground the tailstock and saddle myself on a tool and cutter and had to do a final scrape just to get them right as it is a bit hard getting this right with the different wear factors across the vee and flat but it was literally a light scrape over the flat, I have not gotten around to shimming the gearbox and rack but it has not shown to be a problem yet and it would only need to be about 8 to 10 thou at most. as far as the headstock went i ran the dial indicator over it from the saddle and it was all within .005 of a MM, that could even just be wear on the shaft from the pulley cone running in back gear. The tailstock I had to shim up but I don't think there would be too many Hercus's that would not need this doing to them with the wear they normally show on the bottom sliding faces.

Steve

Originally Posted by allterrain50

I have arranged the regrinding of batches of Hercus beds and have found a professional company of long standing that will do the job. What I propose is an exchange bed service which will reduce the cost of regrinds to just over $300, give or take a few dollars. This will cut the price to a level most can afford and still leave a little to help run the AMH website. If any one wants to take advantage of this service and need to know any more, you should contact me direct on 0438466008.
Regrinding of your existing bed may also be a possibilty, so long as you can fit in with the work schedule.
Mal
Australian Metalworking Hobbyist.com.au

Last change to get your beds in, I will be sending a batch of 9" beds for grinding next week.

Just thought I'd relay the details of how I sent my lathe bed to Mal. I used www.interparcel.com.au . Glen Waverley, Vic to Colyton was $29.32. I booked via the web site, printed the shipping labels and stapled them to a roughly built box that kept the bed safe while on holidays. The down side to this service was the booking window for pickup was 08.00 - 17.00. I think with other services the window can be narrowed but at a price. A Couriers Please van showed up for the picked. Obviously a bit of reselling going on. Hope this is of some use for those about to send a bed.
John

Originally Posted by allterrain50

I have arranged the regrinding of batches of Hercus beds and have found a professional company of long standing that will do the job. What I propose is an exchange bed service which will reduce the cost of regrinds to just over $300, give or take a few dollars. This will cut the price to a level most can afford and still leave a little to help run the AMH website. If any one wants to take advantage of this service and need to know any more, you should contact me direct on 0438466008.
Regrinding of your existing bed may also be a possibilty, so long as you can fit in with the work schedule.
Mal
Australian Metalworking Hobbyist.com.au

One more chance to get your beds in for regrinding.

I have a hold up with the grinding for a couple of weeks, due to pre-existing commitment at the grinding company. That gives a little more time for late comers to add their beds.