Member postings for Steve355

What age are your motorcycles? Are they metric or imperial? What threads do they use etc.? I’d have thought that would be the main consideration in the beginning. You’ll have a miserable time with an old imperial machine trying to make parts for a metric bike and vice versa.

Be aware that if you buy older machines you’ll spend a lot of time fixing and maintaining them. Which is fun and interesting, but may not be the core mission.

Steve

Hi all

Asking for help from someone experienced to check my calculations…

I eventually got a VDH dividing head - good thing I asked on here before diving in and buying a bigger one, because anything bigger would not fit on my horizontal mill. After lots of fixing and fiddling I have it on the mill and aligned.

I want to cut a gear as a test piece, to prove I can do it. I have a 26-35 14.5PA 10DP gear cutter than came with the mill so I thought I’d have a go with that, and try to cut a 26 tooth gear. I made a mandrel, broached keyways etc. See pic at the bottom for the setup.

Next step was to consult Machinery’s Handbook for the numbers. See the calcs on the pic below.

For a 26 tooth gear I think I need a 2.8 inch OD blank (Do)

The dedendum seems to work out at 0.12”, which gives a root depth Dr of 2.36”

So the cut depth is 2.8-2.36 = 0.44”. This seems a lot! Is this correct? Before I start cutting, even though it’s a throwaway piece, I might as well get it right.

Any thoughts appreciated.

Steve

Calcs

Setup

Edited By JasonB on 13/04/2022 16:18:00

I use the lead screw handwheel for all manual feeding on my Zyto. The rack handwheel is far too aggressive and lacks the ability to be precise.

I would say this is the least annoying problem, way down the list after :

1) change gears take ages to reconfigure (often 1/2 hr plus of swearing and getting covered in oil)

2) cross slide and compound handwheels clashing (got around this by turning the compound to face the other way entirely)

3) not a great selection of rpms (on mine anyway)

4) no carriage lock

etc.

other than that it’s a nice little lathe once it’s been set up properly.

Steve

Thanks for the advice all.

Howard, unfortunately I don’t have a 3 jaw chuck (well, I have 2, but none with a Zyto backplate).

In the end I lashed up a “rotary table” from the VDH dividing head I picked up a while ago, but not got working properly yet. Dialled in a 120 degrees twice and it seemed to work.

Problem is, I’m getting about .002 runout on the chuck body. The spindle is Ok, as is the backplate, less than .001. But .002 at the chuck body. I have cleaned it up and it’s still there. It is there whether the screws are screwed in or not, so I don’t think it’s my new holes.

Being a 4 jaw independent chuck, am I right in thinking this doesn’t matter, as I will be indicating in workpieces?

Thanks

Steve

Edited By Steve355 on 02/04/2022 15:48:24

Edited By Steve355 on 02/04/2022 15:50:20

Hi all

Back again after a month or two messing with dark side woodwork things…

I have a problem in that my chuck for my Zyto is broken. One of the operating screws is stripped, it seems. I would have a go at making another one, however, without a serviceable Chuck, that is pretty difficult.

so I bought another one, but guess what, it had a different number of backplate fixing holes (three instead of four). Other than this, the backplate is a good fit.

getting backplates for a Zyto is really hard, it is a 7/8 inch 9 TPI thread. So I can’t easily get a new one. So I’m faced with a choice, drill the chuck to accept the old back plate, or drill the back plate to match the holes in the chuck.

If I drill the chuck I can locate the position of the holes quite easily using the backplate and a centre punch. But I don’t want to drill holes in a brand-new chuck really, and it is probably hardened and so will be difficult to do. Also they will need tapping.

I would much prefer to drill some new holes in the back plate. However, I can’t see how I would locate the holes for the drilling. Possibly on the vertical mill I suppose, if I can get accurate enough measurements. But I’m not really sure how to do that.

Any thoughts or suggestions are welcome. See pic below.

thanks

Steve

Ok, finding one that is rated for full power at 750rpm makes sense.

I found this one that says it runs at up to 1400 rpm, albeit with less torque.

**LINK**

Would this be a suitable VFD?

**LINK**

Steve

Thanks Andrew, that’s what I needed to know.

I wonder why they are so popular then, I’ve seen lots of YouTube videos of people seemingly happily using VFDs with lathes et cetera.

never mind, I’ll have to work on the pulley system.

Thanks

Steve

Back to this project again after a few weeks away from it….

Basically the motor that came with this mill is too fast at 1480 rpm. The original motor that would have been supplied was geared and would have had a much lower rpm (capable of running the mill at 66-2850 rpm). The lowest I can get is 250. I need half that to get into the right territory.

I could add an extra countershaft and pulley, but the bits wouldn’t necessarily be cheap and it would be another project in the way of the mill working properly.

More expensive but easier and more flexible is a motor/VFD package. There’s a chap on eBay selling a VFD, motor, controller box and wiring as a package. Not cheap but it would move me forwards.

The thing is I don’t understand the hp rating of these setups at low rpm. They have linearly lower hp, but high torque - see diagram. My question is, does this matter? Or is it torque I need rather than hp?

I have seen lots of geared motors for sale but they all have very low hp. Again, does this matter? Or are they high torque?

thanks

Steve

Hi all

Disclaimer - I have no link to blocklayer.com…

… but I have used the calculators on that site for building a number of projects, specifically making a roof and a brick arch for my pizza oven in my back garden. Being a DIY moron it has been a great resource.

Recently I’ve been using the rpm / pulley calculator on there to try to work out the problems with my horizontal mill.

I got chatting with Greg, the chap who owns the site, and suggested to him that some machining based calculators may be useful for a large community of hobby machinists. I suggested a surface speed calculator - easy enough would be good. But there are plenty of these around. So I suggested a dividing plate template calculator (I recently bought a little dividing head which will need more plates) as I haven’t seen one elsewhere, and my son has a 3d printer. He knocked it up pretty much overnight and it looks great - see link.

**LINK**

So the questions - feedback on the dividing plate template - what does Greg need to do to make it really useful? - and what other machining calculators might be useful (ideally ones that aren’t ubiquitous)? I’m a beginner at machining so many of you are far better placed to make useful suggestions.

I thought for example a sine bar calculator might be good. Or some gear calculators. Tapers? If you browse around the site you can see the other calculators he has built in other domains.

thanks

Steve

Edited By Steve355 on 08/01/2022 11:02:04

Too late Howard, I’d already drilled the holes! De-burring wasn’t easy on the inside surface.

Bit of a disaster though, when I got it back together it was way too stiff. Took me 1/2 hr to get it back out again. Luckily I don’t think I damaged anything. I’m not sure what’s wrong, there’s plenty of oil in there.

Hi

After having experienced 0.0015 runout on my lathe spindle recently I decided to change the bearing bushes. It’s quite easy to whip the spindle out on a Zyto, and the bushes were cheap, so I thought it’s probably worth it. I got halfway through and found that 1) I’d ordered the right size (achievement) but 2) the oil hole is not 90% offset from the split - so I can’t line up the oil hole and the split simultaneously- it’s one or the other.

The type I managed to get (rightly or wrongly) is as pic below, with a pfte lining I believe.

Any ideas what I should do?

Thanks

Steve

Actually Clive, I may have a better (?!) idea. Another idea anyway. 😎

it turns out the motor drive shaft fits myford change wheels, quite a few of which I have lying about. It shouldn’t be too hard to make a little 2:1 reduction gearbox that sits over the motor spindle. Just need an arbor, a couple of bronze bearings and some sheet steel.

Thoughts?

Doesn’t make a great deal of sense to me either but it’s the original setup. See below drawing. Also I found a list of original motor options … which I don’t fully understand.

hi Jason

The motor rpm is 1480

The countershaft is 525

At the spindle I get 250, 500 or 850 depending on the pulley used.

That all seems to make sense, the motor is just too fast.

I haven’t mapped all the different (12) feed rates yet. When I get a chance I will do that. But I will give it a go later, based on distance per revolution as you say. I can do that with a dial indicator.

TBH I don’t really know, I haven’t got the mill running properly. It is quiet and seems smooth. It is unbelievably heavy. It has a warning on it that says don’t run it for longer than an hour, so for a home milling application I guess it is fine.

Any thoughts on the 3 phase/VFD? What model did you get? I will be budget limited. But it does make sense as the original motor was geared with a much lower rpm. That's how the mill was designed to run - in fact with the geared motor belted directly to the shaft.

Steve

I don’t think so, the feed pulley for the spindle is about as small as it can be and the spindle pulley is about as big as it can reasonably be. See pic below.

I feel a vfd coming on, wallet is getting worried.

Edited By JasonB on 03/01/2022 13:27:46

3” is with the pulley that gives 250rpm on the spindle

Obviously with the spindle running faster the feed will be quicker. But as I understand it I need the spindle running slower (say 120 rpm) and the feed running faster, or at least the same.

Right now it’s like this, with the motor pulley being the small pulley and the large pulley being the driver for the countershaft… this gives 250rpm at the spindle.

Perhaps the easiest/cheapest way to fix it is to increase the size of the countershaft pulley…

Which would give 125 rpm ish at the spindle, a lot closer to the ballpark needed. But the feed would be 1.5 ipm.

I saw an advert for later versions of the mill, which had a hydraulic system for feeding the table. Perhaps that was a solution to the inherent difficulty of having a suitable feed rate and low spindle speed.

thoughts appreciated 🥺

Edited By Steve355 on 03/01/2022 10:40:18

ahhh, so the 0.004 is LENGTH of cut, not depth of cut. I think I get it now!

so if I had say 250rpm and a 20 tooth cutter, and I wanted cuts of 0.004, I’d need 20 ipm feed.

if my mill did 66 rpm and it’s designed to, with a 20 tooth cutter, and I wanted 0.004 cuts, I’d need 5.28 ipm feed.

But the fastest it can go is 3 ipm at 250rpm.

Something is not right about my mill!

Edited By Steve355 on 02/01/2022 15:00:25

I agree, my polisher is by far my most dangerous machine tool, having ripped numerous lumps of metal out of my hands and fired them across the workshop at the speed of a bullet. The trick it to stay away from edges that might catch… still seems to happen though. I have a Sealey polisher, it’s well made and one of my most used and best investments.

Yes.

I need to understand this calculation!