Lets Talk 6X4 Bandsaws !

[timo_gross]

Nice method, I wonder how you make sure, that the two big discs are parallel and concentric to each other.
I guess you will cut a wedge if they are not concentric, or not?

 

[goldstar31]

Agreed but mathematically requites another iden tical diameter of disc.

 

[awake]

Baron and other contributors,

Many thanks for this detailed write up! Very nice to see how others have improved these little saws. I have long intended to make extended jaws with a screw to make the jaws parallel on short pieces (as in post #4 above). Hadn't ever thought of make a "zero clearance" insert - great idea. Also a great word to check the fit of the tensioning mechanism. Many other great ideas as well; these are just the ones that stood out for me.

If I ever tear mine down for an overhaul, the things that I most want / need to do are the following: 1) jaw modification as above; 2) make a new mechanism for setting the blade guide bearings; 3) put a key in the handwheel that adjusts the jaw opening (mine just uses a grub screw which periodically works loose); and 4) rework the underside of the saw in the area around the slot along which the clamping jaw runs to make it parallel with the top - currently I have to keep adjusting the screw that attaches the jaw to the nut depending on how far open the jaws are.

The problem is, it just keeps on working and working and working, and I've hardly ever done a thing to it. I did finally have to replace a blade guide bearing that seized up, and replaced the drive belt, and early on I created a small table that can stay permanently attached for both horizontal and vertical operation. That's it. For all the crappiness of the construction, there is amazing value in these little saws!

 

[BaronJ]

Hello everybody,

another setup, that no one asked me to post. I post it anyway. Presumably only works on blue machines. (sorry for the owners of green machines )
The hypothetical problem at hand. Cutting a disc from the 20mm left over of 1" rod. (I made the left over extra to be able to make the fotos)
View attachment 126511
I put the 20mm long piece into my ER40 collet block only about 5mm length are in the collet. View attachment 126512
I put my ER40 collet block into the machines clamping arrangement.
View attachment 126513
I cut off a small piece for demonstration purpose only.
View attachment 126515
The ER collet clamps at the very front quite O.K. For a saw cut good enough. For milling or turning I would not trust it too much.
View attachment 126516

I hope someone finds it useful. To be able to find the small piece in all the swarf, the mod that BaronJ made with the Al block maybe a good add on. (not for the blue machine, because it has a chip tray under the slot to collect some swarf)

Greetings Timo

Hi Timo,
I would be very wary of clamping a short piece in an ER collet chuck, whilst it will work, you face a real risk of damaging the collet ! ER collets are not designed to grip anything shorter than the length of the collet. The danger of fracturing the back of the slots can be avoided by filling the length of the collet with a piece of the same diameter material.

PS. the solid block that I fitted into the bandsaw blade slot was a piece of steel bar machined to be a good fit into the milled out slot, and secured with a coat of superglue.

Another picture of my bandsaw vise showing how the added extension plates are used.

You can see the advantage of raising the height of wide flat material. You also need to put a block of wood under the arm to prevent the arm smashing down onto the stop switch when using this feature.

 

[BaronJ]

You're right, it was my bronze gear that was destroyed, the steel worm gear was undamaged. I love the plexiglass cover, my bandsaw has a slight leak at the bearing seal, I'm just too lazy to tear it down and replace the seal. Kind regards, Al

Thanks. I'm guessing you are in the USA ! Machine Mart also have the worm, the gear and shaft seals in stock here in the UK.

 

[goldstar31]

Hi Timo,
I would be very wary of clamping a short piece in an ER collet chuck, whilst it will work, you face a real risk of damaging the collet ! ER collets are not designed to grip anything shorter than the length of the collet. The danger of fracturing the back of the slots can be avoided by filling the length of the collet with a piece of the same diameter mat

The surprise is that the New Mk3 Quorn is recommending that the tool holder is an ER one. Mind you having read on the book of destructions, iy is recommended that an alignment tooth is added and that there is a tooth rest and it goes on to provide a facility so that the ends of the cutters are radiased and this is part of the change from the Mark1 to the Mark3.
I am NOT digressing because the new tqo pieces of the rotary table which I have been prattling about- provides for this--- Expressly.

So the jury is OUT

 

[BaronJ]

The method to simply clamp a disc in the sawing machine with the aid of some additional pieces of metal looks is new to me and looks quite straightforward and practical. We - the members of my horological society - use sometimes a bit more cumbersome method. In making gears for clocks it is easier to get the nice cutting brass Ms58 in the form of round barstock than in the form of sheet. Brass sheet where I live can only be obtained in larger dimensions and sheet comes mostly as the tougher cutting brass Ms63. So with round barstock we are often faced with the necessity to cut a thin slice from a leftover disc. The alternative would be to scrap the leftovers and being Dutch we consider that not done. Our solution is to combine two leftover pieces to a 'dumbbell' . This dumbbell shape holds easily in the sawing machine if you support it with a length of flat stock. We can cut useable slices down to 2 mm thickness. I never tried it but I guess you can do exactly the same for leftovers of round steel stock. I made some pictures: soldering the first disc on the electric cooker, soldering the second disc, the finished dumbbell, dumbbell on sawing machine, set up for a slice of 2 mm.

View attachment 126519View attachment 126520View attachment 126521View attachment 126522View attachment 126523

Interesting method of accurately cutting a thin slice of material.

The way that I would do that is to clamp the piece of material as you have done but used a square to get the piece square to the base. Though I do like the square piece on the end of the depth stop.

On my machine I can cut a slice about 2 mm thick with only a few thou variation in flatness, though I admit that I wouldn't want to rely on holding that over more than about 70 mm.

 

[goldstar31]

I've just rummaged throough a large £40's worth of new offcuts and found enough thick angle iron to replace the vise jaws on my metal cutting bandsaw. Amongst the other [ieces there is lots of lighter angle but slso a sizeable quanity of rectangular tubing- some of which is destined for faceplate w ork.
With a few well placed squirts from my MIG I have the rudi,m,ments of a very usable Meccano set.

 

[clockworkcheval]

answer has been connected to the question.

 

[clockworkcheval]

Nice method, I wonder how you make sure, that the two big discs are parallel and concentric to each other.
I guess you will cut a wedge if they are not concentric, or not?

The gears will eventually need a centerhole to mount them on their shaft, so you put in a hole of diameter 4, 5 or 6 mm or whatever and you turn corresponding stubs on the temporary connecting rod.

 

[timo_gross]

Hi Timo,
I would be very wary of clamping a short piece in an ER collet chuck, whilst it will work, you face a real risk of damaging the collet ! ER collets are not designed to grip anything shorter than the length of the collet. The danger of fracturing the back of the slots can be avoided by filling the length of the collet with a piece of the same diameter material.

Hello,

I did not think it can fracture the collet, with the taper at the front for the nut and the slots arranged that it closes more or less prallel I assume (guess) it is fine.
The collets have quite a clamping range, so clamping something that is almost the nominal diameter of the collet or very much undersize might be a significant differnce.
I would not trust this "front only abuse" for milling or turning. For the saw cut or to hold something for belt grinder, I do not overly tighten the nut, so I guess it is O.K. for this kind of work. Still better to put something in the end.

Greetings Timo

p.s. I also edited the previous post, so I hope people will not overlook this.

 

[BaronJ]

The gears will eventually need a centerhole to mount them on their shaft, so you put in a hole of diameter 4, 5 or 6 mm or whatever and you turn corresponding stubs on the temporary connecting rod.

Hi Guys,

Thinking about thin round plates to make clock gears and other thin pieces, I tend to use either mandrels or wax chucks. Or a combination of both.

One of the issues with a wax chuck is the shellac which melts at a relatively low temperature will let the part come loose if the part becomes hot, often ruining the part. I've tried super glue, I've tried double sided tape, even Locktite. They all loosen with heat, and double sided tape can be a right pig to remove.

One trick, if you can call it that is to clean the wax chuck by turning the dirty face off but leaving a small stub/spigot in the centre that will fit into the central hole in a gear. Then super glue, shellac or Locktite used to hold the thin disc. It becomes readily apparent if the work gets too hot but the stub/spigot will keep the work from falling off.

Disclaimer: I'm not a clock maker, though I have made a couple of parts.

 

[BaronJ]

Hello,

I did not think it can fracture the collet, with the taper at the front for the nut and the slots arranged that it closes more or less parallel I assume (guess) it is fine.
The collets have quite a clamping range, so clamping something that is almost the nominal diameter of the collet or very much undersized might be a significant difference.
I would not trust this "front only abuse" for milling or turning. For the saw cut or to hold something for belt grinder, I do overly tighten the nut, so I guess it is O.K. for this kind of work. Still better to put some thing in the end.


Greetings Timo

The ER collet system was never designed to hold very short pieces, its actually a tool holding mechanism, where the tool is intended to be gripped along the whole collet length.

I confess that I found out the hard way when a collet was taken out in two half’s. Fortunately it wasn't an expensive one, just a pain to replace it

 

[timo_gross]

The ER collet system was never designed to hold very short pieces, its actually a tool holding mechanism, where the tool is intended to be gripped along the whole collet length.

I confess that I found out the hard way when a collet was taken out in two half’s. Fortunately it wasn't an expensive one, just a pain to replace it

That means I was just lucky so far that I only used the "trick" for light clamping mostly with a hand tightened Nut.
I will keep in mind what you wrote: "The danger of fracturing the back of the slots can be avoided by filling the length of the collet with a piece of the same diameter material."

Greetings Timo

 

[clockworkcheval]

Hello everybody,

another setup, that no one asked me to post. I post it anyway. Presumably only works on blue machines. (sorry for the owners of green machines )
The hypothetical problem at hand. Cutting a disc from the 20mm left over of 1" rod. (I made the left over extra to be able to make the fotos)
View attachment 126511
I put the 20mm long piece into my ER40 collet block only about 5mm length are in the collet. View attachment 126512

EDIT: In a post below BaronJ advises to be careful with using the ER collet only in the front, the advise is to put at least some piece of the same diameter in the rear end of the collet to prevent it from beeing uneven compressed.

I put my ER40 collet block into the machines clamping arrangement.
View attachment 126513
I cut off a small piece for demonstration purpose only.
View attachment 126515
The ER collet clamps at the very front quite O.K. For a saw cut good enough. For milling or turning I would not trust it too much.
View attachment 126516

I hope someone finds it useful. To be able to find the small piece in all the swarf, the mod that BaronJ made with the Al block maybe a good add on. (not for the blue machine, because it has a chip tray under the slot to collect some swarf)

Greetings Timo

Our instruction 'How to kill a collet' reads 1) don't clean it 2) put a damaged arbor in it 3) don't use the whole length 4) in precision collets use non-nominal size stock.
So I would agree with the other comments against loading a collet for only a short length. However given the clear ease of the method described one might do it anyhow with set apart low quality collets. These are cheap and easy to come by. A single high quality ER25 collet from e.g. the German STALEX company with a guaranteed maximum run-out of less then 5 microns will cost you more (and is worth every penny of it) then a whole set of cheap Chinese collets including the collet holder and including their proverbial high run-out. So without penalty you can use such a Chinese Cheapy in the sawing machine. The run-out doesn't matter. Make sure you combine it with an equally cheap low quality collet holder.

 

[timo_gross]

Our instruction 'How to kill a collet' reads 1) don't clean it 2) put a damaged arbor in it 3) don't use the whole length 4) in precision collets use non-nominal size stock.
So I would agree with the other comments against loading a collet for only a short length. However given the clear ease of the method described one might do it anyhow with set apart low quality collets. These are cheap and easy to come by. A single high quality ER25 collet from e.g. the German STALEX company with a guaranteed maximum run-out of less then 5 microns will cost you more (and is worth every penny of it) then a whole set of cheap Chinese collets including the collet holder and including their proverbial high run-out. So without penalty you can use such a Chinese Cheapy in the sawing machine. The run-out doesn't matter. Make sure you combine it with an equally cheap low quality collet holder.

Hello,
You forgot two things, that come to mind. (just because I try to have the last word always, extremely anoying habit, for the ohters)

5) bore out the eccentric lip of the closer nut, because the chinese are too stupid to make a concentric eccentric.

6) put tool and collet into arbour, then tighten the nut and close as hard as possible

Greetings Timo

 

[goldstar31]

Ah Yes but 'interchangeability' has superceded all sorts of advice and strictures by - well people who are full of the 'exuberance of rgeir own verbosity'
Myford collets will crack if used by commonly available undersize round steel stock.
My set are ;bloody useless/

As for the Quorn and its changes, I made the thing to take dead 1 inch stuff so that apart from other considerations, I could swop and change with 'One inch round' stock of machinery which literally abounds in MY little workshop. ;Bugger the rest'-- tha's me. Do what you want.
So the Quorn Mark 3 comes along with the ER suggestion. Not the best option for me. The ER is 25mm wheras the inch is a rattling fitt of 25.4mm.

So I am a bean counter and rarely subscribes to the Norm- and lyimg in mu garden is an aluminium prop -- and I can have a 1" bore as Nature inteded and I CAN slip om a 25mm ER collet to hold drills and the like.



I'm using that bit that between my esars that wasn't blown out when I served this bloody country ss a Goldstar airman working on sweating ammunition.

You may disagree that is your discretion- I think

 

[ShopShoe]

Just for comparison,

What are you all using for lube in your 4x6 gearboxes?

--ShopShoe

 

[ajoeiam]

Hello everybody,

another setup, that no one asked me to post. I post it anyway. Presumably only works on blue machines. (sorry for the owners of green machines )
The hypothetical problem at hand. Cutting a disc from the 20mm left over of 1" rod. (I made the left over extra to be able to make the fotos)
View attachment 126511
I put the 20mm long piece into my ER40 collet block only about 5mm length are in the collet. View attachment 126512

EDIT: In a post below BaronJ advises to be careful with using the ER collet only in the front, the advise is to put at least some piece of the same diameter in the rear end of the collet to prevent it from beeing uneven compressed.

I put my ER40 collet block into the machines clamping arrangement.
View attachment 126513
I cut off a small piece for demonstration purpose only.
View attachment 126515
The ER collet clamps at the very front quite O.K. For a saw cut good enough. For milling or turning I would not trust it too much.
View attachment 126516

I hope someone finds it useful. To be able to find the small piece in all the swarf, the mod that BaronJ made with the Al block maybe a good add on. (not for the blue machine, because it has a chip tray under the slot to collect some swarf)

Greetings Timo

Great idea!

Likely doesn't work as well but I would put a second piece (same sized material) in the vise at opposite to cutting end. That will work for something long enough to hold in the vice. Timo has a way of holding even if the end to be cut is too short to be fit into the vise - - - - good job!!!

 

[awake]

Our instruction 'How to kill a collet' reads 1) don't clean it 2) put a damaged arbor in it 3) don't use the whole length 4) in precision collets use non-nominal size stock.
So I would agree with the other comments against loading a collet for only a short length. However given the clear ease of the method described one might do it anyhow with set apart low quality collets. These are cheap and easy to come by. A single high quality ER25 collet from e.g. the German STALEX company with a guaranteed maximum run-out of less then 5 microns will cost you more (and is worth every penny of it) then a whole set of cheap Chinese collets including the collet holder and including their proverbial high run-out. So without penalty you can use such a Chinese Cheapy in the sawing machine. The run-out doesn't matter. Make sure you combine it with an equally cheap low quality collet holder.

Does anybody know if 5C collets better tolerate short lengths? As I understand it, they only grip about 1" of material at the front, no clamping action at the rear of the collet - but even so, maybe a short length (< 1") in the collet is still in danger of ruining it - ?