I fix my automatic center punch with the small 775 DC powered tool post grinder

[@howder1951]

I got one of those punches, very cheaply, and the same problem arose after a short time. It sat around until I started admitting that my eyes were no good and began using a magnifying loupe. Since that repair, it has worked as well as can be expected. Great vid, thanks and cheers mate!

[@lloyd4768]

Thanks for the video, I have one sitting on my workbench all apart.

[@noisytim]

Mine got intermittent on Friday. It’s like I need to bang it on the table, every once in a while. I’ll have to try this. Thank you so much! This was great timing!

[@noisytim]

I just took a look. The piston is full of marks and dings. It’s like it’s made of aluminium or something else soft. Maybe I should turn a new piston, out of something harder

[@Xynudu]

That sounds like a good idea Tim. The steel/metal they use in these sure marks easily. It would be easy to make a replacement piston out of some decent harder steel. Cheers Rob

[@Xynudu]

Hi Tim, I took ShawnMrFixitlee's advice and heat treated my piston this morning and it seems to have increased the hardness quite a bit. I got it red hot and quenched in cold water, then wire buffed it to restore the finish. Came up good. Will have to see how it holds up long term. Shawn recons his is still OK after two years. Cheers Rob

[@noisytim]

@@Xynudu That's a great idea! I'll have to give it a try. Maybe i won't have to clean my lathe after all :D Thanks, Rob !

[@RetroSteamTech]

Nice one Rob 👍 I shall remember this when my one finally stops working. Cheers, Alan.

[@HenauderTitzauf]

Aw heck! Now I got to go out to Harbor Freight and buy a lathe, 6 months tutoring in community college, machine classes, to save my $7.00 punch. Seriously, I envy you machine shop types, at figuring out things to keep them working. My dad was that way. He asked me what I learned in the USAF. I was an Aircraft Weapons Specialist. I learned to load guns ammo, misses,rockets, and nuclear weapons. He just smiled. My mom thought that was too dangerous of a job for me. Ah, but the pleasure when an aircraft came back naked, used it all!

[@paulrobilotti9294]

if you are buying punches from Harbor Freight the are down to $3.99

[@frankgallego3782]

Gee, I'm deciding which one of my lathes I should use!

[@columjevens4612]

Cheers Rob , will try that with mine . Love that tool post grinder set up 👍....P.S when I got my first center punch ,and still have 40 years later, I had to convince the hardware store , that I was going to use it for its propper use , apparently they were restricting them at the time because messers were using them to smash and grab from cars,☺

[@joandar1]

I have an Eclipse type and have used it for 30 plus years, when I need to then I will perhaps have to see what what the issue is. John, Australia.

[@paultrimble9390]

Nice channel I’ll have back watch old stuff to catch up

[@robstirling3173]

Thanks Rob, I will go and do that to mine! Stay safe....

[@gary7684]

Very timely, I noticed mine playing up yesterday.

[@Xynudu]

Hi Gary, the tip is hardened and up to the task, but the piston I refaced is made of cheesy metal. Expect it to fail sooner rather than later. Easy to fix, but shouldn't happen if it was made right. Cheers Rob

[@paskmoe4969]

..i ran into the same problem...tried your fix...and it worked..thx a lot.

[@Xynudu]

Glad it helped

[@davidtubat2472]

Thanks for sharing mate..got my auto centerpunch firing again

[@Xynudu]

Good to hear. Cheers Rob

[@Xynudu]

NOTE: DO NOT OIL the internals or it will never work. If the cheesy piston that I refaced in video was hardened or replaced with one turned from tool steel I expect the problem would go away for good. Cheers Rob

[@_bodgie]

Have you considered trying to harden your piston Rob? I'd reckon it wouldn't be hard to give it ago, perhaps it may be worthwhile experimenting next time you need to do this. I've fixed/improved a couple of these punches because of your advice, thanks for that.

[@Xynudu]

Hi Jason, I did harden the piston after ShawnMrfixitLee told me he had done it and it seems to have improved things a lot. The steel used will definitely harden with a basic heat red hot and quench technique. Cheers Rob

[@shawnmrfixitlee6478]

if you heat treat that piston it helps them to last . I had the same issue Rob ! ENJOYED..

[@Xynudu]

Hi Shawn, I just went and did that and it seems to have hardened it up. I ran it over the oil stone after and hardly marked it. Looks like they used the right steel but didn't heat treat it. Cheers Rob

[@shawnmrfixitlee6478]

@@Xynudu Good job , Should last a bit longer ! Mine works great after 2 years ..

[@AmateurRedneckWorkshop]

G'day Rob. Keep your nose to the old grindstone.

[@TigerCarpenter]

I happen to have the exact same automatic center punch. mine is working fine so far, but I will remember your fix, in case it starts getting a hiccup. sometimes I wonder if there is JUST ONE factory per item in China.

[@boastyy]

Just bought one of these and I thought it was not working as when I pushed down there was no click. Got it working, but with mine it takes much more force to push down before it goes click and leaves a mark. Mine looks identical to yours, perhaps it works like this because its new and there's more force on the spring. Took it apart to see how it works and it seems like the the pin which goes in the spring is held off centre until the spring is compressed then the pin moves towards the centre and slips into the hole causing the click noise and marking the dent.I guess if someone takes off too much material off the cylinder its like reducing the spring pressure making a weaker punch. Thanks for the video man.

[@Xynudu]

That sounds about right. If the pin end edge is not clean/sharp it won't click over the edge as it should and will just sit there doing nothing. Cheers Rob

[@boastyy]

@@Xynudu Thanks man!😀

[@txlabmansteamtoysmore4980]

Very helpful Rob. Love the technique. Thanks. 🤠

[@Xynudu]

Those little cut off discs can do a lot more than just cut :) I often use then to face metal. Cheers Rob

[@davidschwartz5127]

Thanks for the tip, I have 3 of them and none work every time even my old Starrett.

[@billbaggins]

Got about half a dozen of those clicky things, if I ever use one enuf to piss me off this will be handy.

[@metalshopwithtroy5755]

Good video thank you for your efforts

[@Xynudu]

Thanks for watching!

[@joeduda8507]

thanks for the video I enjoyed it

[@Sabastianspreadworth]

You've got a lathe so why don't you make a load of them then swap them out when they wear?

[@allpraisebob]

I gave up on this style center punch a few months ago because they inevitably stop working after just a few uses. Although it's interesting there is a possible fix, the design is still fatally flawed and will continue to let you down as long as you keep giving it a chance to do so. In frustration I bought a Neiko 02638A at random a few months ago for all of about $10US and it's still going strong after several dozen uses (impressive, when compared to the 2-3 uses I typically get out of these $2 ChiCom specials).

[@Xynudu]

I think you will find the Neiko uses the same design Jeffrey. If the cheesy piston was replaced with decent hard steel in ones like I repaired, the problem would go away for good. Cheers Rob

[@allpraisebob]

@@Xynudu Nope, the inside of the Neiko is definitely different. I didn't know that before I bought it, of course, but the first thing I did when I got it was unscrew the barrel to make sure it wasn't the same design just with a red knob on the end.

[@jossfitzsimons]

I've dumped a couple because I couldent figure what was wrong. Thank you.

[@johnlucier5654]

Apparantly another fix is to open up the tapered hole in the body just a bit. This allows the tapered lower pin to get further misaligned in the cocking phase.

[@Xynudu]

OK. Thanks for that tip. Cheers Rob

[@johncrea9395]

Instead of dry newspaper to catch the grinding dust, spritz with WD40 and the dust sticks to the paper John

[@Paullyb79]

Would it be worth making this out of a hardenable steel?

[@Xynudu]

Yes.

[@SeanBZA]

Wonder if you could case harden that little thing, then polish it up to a sharp edge. Would hold the edge for a long time then, even if it is made from the cheapest of cheap recycled mystery steel scrap.

[@Xynudu]

You could try. It might chip in this application. Easier to make up a replacement piston in steel which can be hardened.

[@tiberiu_nicolae]

*Pulls out industrial heavy lathe*

[@dws_damiansworkshop]

If the current piston is soft, why didn't you just turn the edge? Grinding soft materials doesn't make sense to me.

[@Xynudu]

I doubt you would get the level of finish a grinder will give.

[@dws_damiansworkshop]

@@Xynudu maybe, depends on the grinder and cutting tool used.

[@Sea-Dog5496]

Hi Rob. I have the exact same one as does everyone else in the comments. I was wondering if it was worth the effort to try and heat treat the piston? I use it almost every day and it wears so easily the fix does not last long.

[@Xynudu]

Hi Ed, ShawnMrFixitlee suggested that, so I did it this morning and it appears to have hardened the steel considerably. I tried it on an oil stone and it barely marked it. So it appears they used the correct steel, but didn't heat treat it. LOL Worth a try. The other alternative is to make another piston out of tool or spring steel which will harden. Cheers Rob

[@robertgeldard1273]

Yes that part needs to be flat but the pin also needs to be square faced

[@jasonsadliberty1503]

OMG....little piece of 300 grit wouldn't do the trick?... I feel like I took my cheap toro lawn mower into an authorized Range Rover frame straightening and specialty collision Center.....I'm sorry My bad. Wrong shop. I must not have been paying attention..~~~~ Was just looking for a cheap center punch repair shop around here somewheres. Oh...nice tools by the way 👍👍❗☮️

[@glipho01]

Good, ❤

[@Allegedly2right]

Got one of them in me shed haha behave yourself DIY it

[@richardstarr9223]

To do it easy? Much quicker and easier to hit it w some wet dry on a flat block. I think what you meant was just another way to show of me Dremel doohickey

[@Xynudu]

Depends how poorly made it is.

[@johnlucier5654]

Dont see how your grinding arrangement could make the face flatter.

[@proten40]

Not hard enough. Heat treat it and then polish it.