Is anyone willing to make me a spring loaded engraving tool holder? I've seen the one for $300-400 and that seems a bit pricey for me. I will be engraving text on 3" x .75" brass plates with a rotozip or similar, so it needs to be accurate. I have paypal and would like to get one soon if possible.

thanks

HEY, I need one also. email me if someone is making them. wirewerks@verizon.net Thanks

I have made 3 of them now, but they are used for shallow engraving with the spindle off. ( drag engraver) got the idea from the machinists bedside reader. They work perfectly with 0 backlash. Nice tool to have.

I could share my autocad drawing, or just make you one. I'll post pics later.

Paul

Ha ha thats wierd timing, ive just this very minute almost finished my prototype for a spring loaded engraving tool, it's going to need some refinement and I have no idea on what springs to use.

Below is my example, im not too happy with the design at the moment, it was more a proof of concept, the nuts are to be replaced later with nylon lock nuts and threadlock, I also would rather it if the bit holder was of a collet type design, but im still learning with my lathe.

If anyone has any design advice it would be welcome.

Once the design is improved and proven I may sell them.

Ive been thinking of using dremel style collets, but making the bit holder myself, still struggling a bit with threading on the lathe.

I ran it for over an hour at 30,000rpm (with me out of the workshop due to those nuts) and it was fine, as for accuracy I was really quite impressed, could see no blurring and it left a pin prick indentation from where it was running, the in prick was the same size as the end of the bit.

I am however still learning and probably have a long way to go.

My main use will be for pcb's where this is very little lateral force, would'nt like to say how it would cope with aluminium etc.

If I can get a 6mm and 3.175mm barrel lap I think it will be better, I also think the collet system is a must, aswell as a better design for the bar that runs up the slots, perhaps split pins or circlips, but I have not found any small enough.

The pcb was done before I made the tool. just so you can see they type of work i will be doing with it

DJH

Hi DJH,

PCB looks good and so does your spring loaded tool. Did you try that centring devise I posted a link for and if so what did you think?

John

Thanks

I most certainly did, it's still a little bit of a struggle and the line you align it with is a little bit thick, but it definatley helps, still not dead on but the end slides up fairly smoothly, probably better if I could find an 8mm chucking reamer/barrel lap

DJH

Thanks

I most certainly did, it's still a little bit of a struggle and the line you align it with is a little bit thick, but it definatley helps, still not dead on but the end slides up fairly smoothly, probably better if I could find an 8mm chucking reamer/barrel lap

DJH

Cheers :)

What is the purpose of a spring loaded cutter. Is it kinda like THC on a plasma cutter? It will allow you to etch PCB's that aren't perfectly flat?
Just curious. Thanks.

Yep thats it LeeWay

Ive found it near impossible to get pcb flat with various different methods, it only needs to be out by a little bit to mess it up.

DJH

DJH,

How do you plan to regulate the depth of cut with the pictured design?

John

well, it's the same principal as the ones sold by 2linc.com for a lot of money, once the correct spring is selected, although the force is not linear, it seems linear enough in that regardless of height, there is just enough force to go the required depth.

Im going to fit a tensioner in the top so I don't have to keep swapping springs.

Ive never used one before, but i have seen one that was engraving a 22mm copper pipe over about 100 degrees of it's surface, and the depth was the same as far as i could tell, we opened his tool up and it was just a spring and a form of collet.

Hope that makes sense, theres no harm in me trying it anyway

DJH

Thanks, you will have to let us know how it performs.

Well first test results:

I loaded it up, lowered the Z axis until the tip touched the pcb, lowered a bit more to take up some slack, then jogged in a straight line, lowered some more and jogged some more. The line depth was pretty damn uniform, there were some marks from where I stopped it and lowered it, but of course it would be moving when that occurs under normal use.

But sadly there is a problem, while trying to make a pcb, theres was too much play between the bit holder and the main body, i think i need a reamer to make sure the bore hole is near perfect, and then make the bit holder out of steel instead of aluminium, i think the bit holder needs to be thicker too, so does anyone know where I can get a 7mm chucking reamer (is that the same as a barrel lap?

At least the concept seems semi sound atm anyway, although i do have ideas to vastly improve things, I need my 4 jaw chuck to arrive and I need some reamers and a Die stock holder

DJH

Just had my 4-jaw chuck, Tailstock Die holder and new cutters arrive so i can try and make the new and improved version :)

DJH

You need a zero backlash tool in the x/y directions. Make that perfect first, then worry about the z. A long reamed hole with a perfect fitting shaft is an easy way to do it. Leave the shaft untouched drill rod, ream a hole in the tool holder body to match. You can make the reamer out of the same sample of drill rod.

See the Machinists Bedside Reader for more info. (sorry, dont have a link)

Just a suggestion, slot the holder thru and use a spring pin instead of the screw and nut. That way there is nothing to fly off.

Looks like a good tool to have, when will you let us know the price? ? ?

Larry

Thanks for the advice guys

I have considered split pins, e-clips etc, all of which I may try if i can find the right sizes. as soon as I have found one that works well, i will be able to see how long they take to make and come up with a price.

The spring tensioner is a must tho, so im going to test that this weekend.

DJH

I WAS THINKING, WHY COULDN'T YOU USE SOMETHING ON THE LINE OF AN AUTOMATIC CENTER PUNCH THEORY. MAKE THE ENGRAVER TO HOLD A COLLET INSTEAD OF BEING THREADED. THEN HAVE IT ADJUSTABLE AT THE OTHER END FOR THE ENGRAVING PRESSURE THAT YOU DESIRE DEPENDING ON MATERIAL USED. JUST A THOUGHT.

Hiya

Thats an interesting idea, I will try and get one and see what I can do with it.

with regard my version, I have a set of reamers now so I hope to spend some time making a new version

DJH

Heya

Just an update, have been tidying up the workshop, has taken 3 days, so not got much done, ive made the new outer section, just gotta work on the inner now and give it a test, this one is someway between the one pictured, and the one I proposed.

DJH

DJH,
what model miller are you using to do the PCB's? any good for moderate SMT stuff? any more photo's as examples?

Ray

Here's a drawing for a graver I made a few years ago. It's ideas are based on the one described in 'The Machinists Bedside Reader'. The long reamed hole ensures that theres zero backlash at the cutting tip.

It's been a great tool for engraving plexiglass and aluminum.

I put a detail for a simple D reamer on the drawing too. It works like a charm. I don't bother tempering the tip after hardening, just leave it full hard.

Paul