PDM30 - Friction Dials

[Canuck75]

Out of habit I always zero the X-Y dials on my bench mill when a reference position is established so it is easy to come back to that zero. Yes I have a DRO, but sometimes I use the mill in full manual, and, like I said, just habit. Anyways, my mill used thumbscrews to lock the X or Y dials which is pretty basic but in keeping with the price point of these machines. More than once, however, they have loosened on their own (gremlins), so it was time to do something. I always liked friction set dials, so took things apart, turned the groove under the graduation ring down to accommodate two O-rings until I had the right friction fit to hold the ring in place. Just replaced the thumbscrew with a grub screw for looks. Guess I better to do the Z as well.
Thanks for looking.

 

[Canuck75]

Out of habit I always zero the X-Y dials on my bench mill when a reference position is established so it is easy to come back to that zero. Yes I have a DRO, but sometimes I use the mill in full manual, and, like I said, just habit. Anyways, my mill used thumbscrews to lock the X or Y dials which is pretty basic but in keeping with the price point of these machines. More than once, however, they have loosened on their own (gremlins), so it was time to do something. I always liked friction set dials, so took things apart, turned the groove under the graduation ring down to accommodate two O-rings until I had the right friction fit to hold the ring in place. Just replaced the thumbscrew with a grub screw for looks. Guess I better to do the Z as well.
Thanks for looking.

I machined up the bits to also make the Z dial into a friction fit today. A little more complicated than the X and Y. Turned the back of the hand crank and pressed on an AL collar to hold the O-ring. Only used one O-ring as it seemed to give plenty of grip to hold the dial. Dual O-rings on the X and Y was maybe overkill! Bored out the back cavity on the dial and pressed in a plug to accept two spring loaded buttons which apply continuous pressure to the index plate behind the dial. This was a great idea that another H-M member posted to get rid of the hand wheel flopping about against its backlash. Finally a knurled ring with a bore for the O-ring was turned and pressed on the front of the dial. Nice to get rid of the thumb screw on this dial was as it always seemed to be a the back when you wanted to set it.

Thanks for looking

 

[bulgie]

Inspirational! I just got mine, an Enco, probably Chinese. Embarassingly bad fit'n'finish but the price was right.

Incredible to me, the little riveted-on plates that are supposed to have the zero line have just nothing. I assume there was a hashmark that was just painted on, and after the previous owner wiped with a rag a few times all the paint was gone, now it's as featureless as the crotch of a Ken doll.

I guess I'll just tap it with the edge of a chisel to put in an indentation, then fill that with black paint. But how much would it have cost them to do that at the factory? No pride?

Sorry to change the subject, but how long have you used it without the top of the "coffin" for the belt drive? I'm afraid that would collect too much dirt in my shop, but the reduced hassle when changing speeds might make it worthwhile to leave it off.

Thanks for sharing your mods, nice photography too.

-Mark

 

[Canuck75]

Inspirational! I just got mine, an Enco, probably Chinese. Embarassingly bad fit'n'finish but the price was right.

Incredible to me, the little riveted-on plates that are supposed to have the zero line have just nothing. I assume there was a hashmark that was just painted on, and after the previous owner wiped with a rag a few times all the paint was gone, now it's as featureless as the crotch of a Ken doll.

I guess I'll just tap it with the edge of a chisel to put in an indentation, then fill that with black paint. But how much would it have cost them to do that at the factory? No pride?

Sorry to change the subject, but how long have you used it without the top of the "coffin" for the belt drive? I'm afraid that would collect too much dirt in my shop, but the reduced hassle when changing speeds might make it worthwhile to leave it off.

Thanks for sharing your mods, nice photography too.

-Mark

Hi Mark, thanks for the comments.
Does make one wonder about pride of manufacture but on entry level machines cheap wins every time. Friend of mine have a small RT and when the slots are squared up to the base the index mark is off (?), very annoying! Anyways, it great fun improving them.
I can hardly count the things I've changed, getting rid of the hood being one of them - my reasoning was what was the point of making a quick release on the belt tension if you still have to unlatch and lift the hood? In my case the shop is not too dusty and I've very limited head room (7'), so if the head is raised the hood can hit the ceiling! I don't know if there is a way to call up my particular posts in "Rong Fu Machinery" but if there is, take a look, you might be interested in some of my mods. Big ones were changing out the quill bearings to sealed angular ball bearings, making the quill handle indexible, and a mod to keep the X. My machine was made in Taiwan in 2000 and was of reasonable quality.

Good luck with your efforts.

 

[bulgie]

I can hardly count the things I've changed, getting rid of the hood being one of them - my reasoning was what was the point of making a quick release on the belt tension if you still have to unlatch and lift the hood? In my case the shop is not too dusty and I've very limited head room (7'), so if the head is raised the hood can hit the ceiling!

Yeah low ceiling here too. I'll try it with the lid off for a while and see how it goes, not hard to vacuum it now and then if the crud piles up. Maybe even leave the lower half of the coffin off as well. I keep my hair short and don't wear a scarf or a tie, so "what could possibly go wrong?"

My plan is to use it as-is for a few months or a year before spending too much time on improving it. I have to fight my natural tendency to spend all my time on making tools, or making tools to make tools to make tools, instead of making the things I got the mill for. In my case, custom bicycle frames. (I used to do it full time before I retired, as a wage-slave. Never had my own shop before.) I have some kind folks who say they're eager to put down a deposit, but I'm already a year or two later than I said I'd be ready to start building. Getting a mill wasn't even in the plan, so now that set me back another month or more (probably — we'll see). I haven't even started welding the stand for it yet.

Still, I freakin' love the mods that you and certain other round-column sufferers have made. It's really tempting to dive into THAT as my new hobby!

 

[matthewsx]

Yeah low ceiling here too. I'll try it with the lid off for a while and see how it goes, not hard to vacuum it now and then if the crud piles up. Maybe even leave the lower half of the coffin off as well. I keep my hair short and don't wear a scarf or a tie, so "what could possibly go wrong?"

My plan is to use it as-is for a few months or a year before spending too much time on improving it. I have to fight my natural tendency to spend all my time on making tools, or making tools to make tools to make tools, instead of making the things I got the mill for. In my case, custom bicycle frames. (I used to do it full time before I retired, as a wage-slave. Never had my own shop before.) I have some kind folks who say they're eager to put down a deposit, but I'm already a year or two later than I said I'd be ready to start building. Getting a mill wasn't even in the plan, so now that set me back another month or more (probably — we'll see). I haven't even started welding the stand for it yet.

Still, I freakin' love the mods that you and certain other round-column sufferers have made. It's really tempting to dive into THAT as my new hobby!

I got tools to make tools to fix tools for makin' tools.

Bought my RF30 clone from a custom bicycle frame maker, and my Hardinge BB4 from a different one. Would love to see some of your work, bicycle or otherwise.

I've also removed the top cover from mine but not the bottom piece since it doesn't interfere with the shelf I have behind my mill. Figure there are lots of spinny-cutty things at the botom of the spindle too....

John

 

[RJSakowski]

The top cover has been gone from my RF30 clone for more than thirty years. At its lowest height, the bottom cover is above eye level so there is little danger from the exposed belts.

 

[bulgie]

Bought my RF30 clone from a custom bicycle frame maker, and my Hardinge BB4 from a different one. Would love to see some of your work, bicycle or otherwise.

OK if y'all don't mind an off-topic thread hijack...
My Brilliant Career as a custom framebuilder was '77 to '99 and I had a whole 'nother career (in IT) after that, so it's been almost a quarter-century since I made a bike frame. Long enough for me to forget all the bad parts and only remember it as fun. Seems like a harmless retirement hobby.

I almost never took pictures in all that time. But here's a nice road frame I made for myself in about '86, taken apart in this photo album so it's a bare frame. I'm going to do some mods and a repaint. Here's a titanium mountain bike I made for my wife in '94, years later converted to a utility bike ("grocery-getter") with the addition of strong cargo racks made of 4130 CrMo tube. I probably won't make Ti frames at home though, I think it'll be steel only from here on out.

I hope to have some new work-in-progress to share by say Spring, finished product by Summer. Yes a bike frame can be built in a day but I'm very slow! Also I have to build fixtures and lots of little tools like positioners for the fiddly bits that go on frames: brake pivots, cable housing stops and guides, pump peg etc. — in bikie jargon those are known as braze-ons. The jargon is so well entrenched that we call them that even when they're tig-welded instead of brazed. OK probably TMI, will stop there.

-Mark

 

[bulgie]

The top cover has been gone from my RF30 clone for more than thirty years. At its lowest height, the bottom cover is above eye level so there is little danger from the exposed belts.

Sounds like the consensus is leave the lower cover on. Not sure why I would want to remove the bottom cover, probably just because it "looks cooler" without it.

Oops there I go again with the thread hijack.

 

[matthewsx]

OK if y'all don't mind an off-topic thread hijack...
My Brilliant Career as a custom framebuilder was '77 to '99 and I had a whole 'nother career (in IT) after that, so it's been almost a quarter-century since I made a bike frame. Long enough for me to forget all the bad parts and only remember it as fun. Seems like a harmless retirement hobby.

I almost never took pictures in all that time. But here's a nice road frame I made for myself in about '86, taken apart in this photo album so it's a bare frame. I'm going to do some mods and a repaint. Here's a titanium mountain bike I made for my wife in '94, years later converted to a utility bike ("grocery-getter") with the addition of strong cargo racks made of 4130 CrMo tube. I probably won't make Ti frames at home though, I think it'll be steel only from here on out.

I hope to have some new work-in-progress to share by say Spring, finished product by Summer. Yes a bike frame can be built in a day but I'm very slow! Also I have to build fixtures and lots of little tools like positioners for the fiddly bits that go on frames: brake pivots, cable housing stops and guides, pump peg etc. — in bikie jargon those are known as braze-ons. The jargon is so well entrenched that we call them that even when they're tig-welded instead of brazed. OK probably TMI, will stop there.

-Mark

Nice work, thread hijacking is a fine art around here that few seem upset by. I also worked in IT right up till last year when I got recruited into manufacturing engineering.

Yes, keep the lower cover on, makes it much easier if the safety inspector comes calling

John