Power Hack Saw Flee Market Find

[IronHorse]

It was a some what rainy day up at the Burls Creek Automotive Flee Market on Friday, but I did make a nice score. I found this 1981 D-M Tools DMH-80 portable hack saw, and I ended up getting it for $40.

It is a nice simple design, a geared motor turns a circuler crank disk, with the crankpin sliding the carrage back and forth on 2 guide rods.

I found that standard 10" blades from the hardware store work good and I cut a few materials to try it out. Here is a video of it cutting a 1" rod of Aluminum. This is a fine blade on the saw, and I think a course one would cut faster. They only had fine ones today.



I am sure this machine will save some "pain" over the next years projects.


IronHorse

 

[Swifty]

Good find. As the blade wears, put a packer in front of the fixed jaw to allow use of the other end of the blade. Just watch out that the blade holder doesn't hit he piece being cut.

Paul.

 

[Tin Falcon]

Interesting . I do not really ever seeing one like that even in catalogs. I like it. for steel bar or drill rod it could be handy. One of the local HW stores has starrett HS blades fairly reasonably priced. how bad does it shake the bench ?
Tin

 

[IronHorse]

Great idea Swifty, I was wondering how to use the rest of the blade.

Tin...Does not shake too much, stays put, but I would not leave the room

I was looking aroung the internet and there seams to be more of a selection if I used 12" blades. I could cut to length, but how could i "drill" a hole in the end?

IronHorse

 

[Gordo]

It is easier to punch a hole in the blade than drill one. I use a Roper Whitney punch when I do it.
Gordo

 

[robcas631]

I'd sure be happy if I could obtain one of those!

 

[gerritv]

IronHorse, how does one find out about these interesting markets in the area? I assume that there is a lot more than automotive items there.

I am in Toronto as well.

Gerrit

 

[Speedy]

I need one of those

wooo three of us from toronto

 

[Tin Falcon]

hmm flee market . Flee to run from ! so you take your booty and run?
got me thinking, in the US we call them flea markets. some debate on origin of name. One theory is from a market in France translated " A market where one catches fleas. " another story is it originated from a 1830s horsetrading market in Texas called the Fly Market. At the prices some folks charge for there scrounged or surplus wares it is because it is where the blood suckers hang out, or is that a place called congress or in your case Parliament. HMMM anyway nice find. Sorry could not resist.
Tin

 

[Jeff-in-PA]

It is easier to punch a hole in the blade than drill one. I use a Roper Whitney punch when I do it.
Gordo

I use a 1/4" cylindrical stone in my dremel to grind a hole where I need it in the blade. ( No punch )

I make a mark along the entire width with a marker and then grind using the edge to make a small divot. Turn the blade 90* and repeat. Turn 90*, repeat as many times as needed. Once you think you're over half way thru, turn the blade over, match the line and grind from that side. Just a few minutes makes a nice round hole.

Works great with my power hacksaw

click

 

[Brian Rupnow]

Nice little saw. I have never seen one that small or that style.---Brian

 

[IronHorse]

IronHorse, how does one find out about these interesting markets in the area? I assume that there is a lot more than automotive items there.

I am in Toronto as well.

Gerrit

These are four of my favorite shows/markets in Southern Ontario

Burls Creek Automotive Spring Flee Market.........Hundreads of vendors, Auto,tools, rusty stuff............First week June
Cookstown Steam Show.........Lots of engines, Few vendors, REAL rusty stuff..............CanadaDay Long Weekend
Milton Steam Show............More engines, lots of models, REAL rusty stuf...................July Long Weekend
Burls Creek Automotive Fall Flee Market.........Hundreads of vendors, Auto,tools, rusty stuff............First week Sept

I usually find 90% of my yearl junk at these places.


IronHorse

 

[joegib]

Just posting to say that there is at least one other of these saws around!

I bought it new around 1984 and after 30 odd years it's now a little timeworn. Still works fine within its limitations, though. In some ways it's rather crude — the automatic cut-off is simply a bolthead on a bracket that knocks off the toggle switch as the arm assembly descends through its arc. There's no damping arrangement and in practice with bigger diameter work, I have to put a weight on the arm to keep the blade up to the job. Even so, it's the one piece of equipment I wouldn't be without!

Like others, I'd never seen another unit like it advertised or referred to until Ironhorse made his posting. My unit came from a firm called Graham Engineering based in the West Midlands. They were one of the early importers of Far Eastern gear into the UK though I was under the impression their stuff was mostly Korean. I suspect these units were eclipsed by the portable bandsaws that were coming onto the market around the same time — I imagine the bandsaws were more generally useful for most people. In my case I only had a small workshop so the hacksaw suited me better.

Joe

 

[gus]

I need one of those

wooo three of us from toronto

Me too.I am sick and tired of manual hacksawing m.s.steel bars.
With a balcony as machineshop,I have no space for a powered hacksaw.
Saw my masters manual hacksaw 1/2 " m.s.plates .Not only he cut fast and straight,he seems to enjoy the chore.

 

[lathe nut]

IronHorse, never seen one like that, I have several of different types even made one, that is a good looking compact one, could we get a shot of how the motion is transfered, thanks, Lathe Nut

 

[joegib]

Don't know if Ironhorse has had a chance to open up his machine yet but perhaps I can answer since I had a look at the innards of mine years ago.

The motor output shaft carries a small spur gear that drives a larger spur gear within the gearbox housing to achieve speed reduction. On the downward-facing side of the large driven spur gear is an offset fixed stubby post or spigot that projects into the box housing containing the bar slides that carry the blade holder.

If you look at Ironhorse's picture here:

http://i292.photobucket.com/albums/mm10/ironhorse2008/Power%20Hacksaw/P9080082.jpg

— the blade holder can be seen as an elongated 'H', the ends of each upright being bored for the slides. In addition, the uppermost side of the left arm of the 'H' (on the motor side) is slotted. So, the fixed spigot attached to the periphery of the output spur gear is located in this slot. The effect is to turn the motor/gearbox rotary motion into reciprocating action. This is an example of the 'Scotch Yoke' principle illustrated here:

http://www.mekanizmalar.com/scotch_yoke.html

Joe

 

[gerritv]

Awesome reminder, I never thought of those places as a source of tools. I have placed reminders to check dates for each show,
Thank you.

These are four of my favorite shows/markets in Southern Ontario

Burls Creek Automotive Spring Flee Market.........Hundreads of vendors, Auto,tools, rusty stuff............First week June
Cookstown Steam Show.........Lots of engines, Few vendors, REAL rusty stuff..............CanadaDay Long Weekend
Milton Steam Show............More engines, lots of models, REAL rusty stuf...................July Long Weekend
Burls Creek Automotive Fall Flee Market.........Hundreads of vendors, Auto,tools, rusty stuff............First week Sept

I usually find 90% of my yearl junk at these places.


IronHorse

 

[PointFive]

To Jeff-in-PA:
I have the kit of parts (but no instructions) to make the saw in your picture. I believe the kit was sold by Cedarburg of Wisconsin, original an article in Popular Science (Google has the article).

Do you or anyone else happen to have the original Cedarburg instructions for making this saw?
PointFive

 

[IronHorse]

Joegib: thanks for posting the pictures, I have not seen another one until your post. I thought the auto-shutoff was home made, but yours has the same one.

I know it has being 30 years, but do you remember what you paid for it?

Thamks
IronHorse

 

[joegib]

Hi Ironhorse,

I paid £60 which at the then very low £—$ exchange rate equates to about $80US.

I don't know what the cost of industrial machines is nowadays but the only hacksaw machine aimed at home users I know of is the Sieg unit marketed by Arc Euro — see here:

http://www.arceurotrade.co.uk/Catalogue/Machines-Accessories/Saws

OK, it looks to be a better made machine than the one we have but at over £400 a pop (including shipping) I wonder how many takers they have. By comparison a bandsaw can be had for less than half that price —

http://www.warco.co.uk/metal-bandsa...2-cy90-3-12-mitre-arm-bandsaw-with-stand.html

— if you've got the room to house it.

Joe