Power Hacksaw (1/16th)

[lab-dad]

Next up on my list of machines is the power hacksaw.
I will be using Brett Gallant's O scale model (MT-550) as my reference.

First off though I need to understand how the machine really worked.
All the power hacksaws i have seen (modern) pivot up at the front and use the sawframes weight to move through the cut material.
I have searched the internet but only found one good image  

On the model it looks like the sawframe moves vertically.
And (I am assuming) it looks like an operator would turn a crank to lower the sawframe.
Wouldn't this also make the linkage to the eccentric have to change length (get shorter) as the sawframe moves down?

Also it looks like the vice bracket can pivot in order to cut angles?

I'd like to make all these things "work" on the model; The vice, the feed, the pivot & I'd also like to be able to spin the drive wheel and see the blade move back & forth.
I'm trying to unthrone Dallas as the crazy king!

Any help is always appeciated!
-Marty

[marc_reusser]

I'm trying to unthrone Dallas as the crazy king!

Any help is always appeciated!
-Marty

To each scale there must be a crazy.

Looks like another great build....

Don't look to me for help...I know nothing about this stuff  

M

[EZnKY]

I have a Marvel DrawCut No. 2.  This is essentially the same saw as the one made by Western Scale Models.
I could take a movie of it if you'd like, but there are also a number of movies on youtube showing the saw in operation.

Mine's been converted from flat belt drive to an electric motor sometime in the 20s.

[lab-dad]

Thanks Eric,
I "think" the WS one pivots at the base.
I beleive the blade on the 550 moves vertically.
I will look on you tube.
Knowing the name/model of my prototype would be helpful.
Marty

[granitechops]

Going from memory, the blacksmith in Exeter had a real ancient hacksaw, probably 3 ft blade,  it looked like the  power stroke  was delivered horizontaly, to the rear base of the saw frame, which pivoted as neccessary from the end of that arm as it  cut through the material. Obviously such a machine would only be useful for relatively small cross sections, anything really big would need either a longer saw frame to keep the cutting angle reasonable or an automatic horizontal adjustment.

In the one I saw the work was at the front end of the blade allowing for the most shallow cutting angle

In your example of the 550 what exactly did the feed move?
was it perhaps a vertical feed of the vise?

Judging by the wheel size, 14", the blade frame is only about 28-30" long  

Incidentily he moved into a small building that was left over when the huge foundry in Exeter ( Tan Lane?) was demolished so his saw may have actually come from the foundry

[Malachi Constant]

Yes, well, I think I may be the King of Demented Little Silly Details ... and you'll easily rise to King of Clever Mechanical Miniatures, if you're not there already! 

No idea how it works ... look forward to seeing how you sort it out (and looking for videos and getting the right leads there sounds like a real good step) ... and imagining that it would make a helluva nice cheese slicer! 

Cheers,
Dallas

[michael mott]

Marty, the small ratchet wheel is in all likely hood a feed ratchet that would be operated by the action of the saw moving backwards, so a constant feed, perhaps similar to a shaper.

Michael

[lab-dad]

Well after lots of drinking, er THINKING and research I think I figured it out!
I am still amazed at the quality of Charles Brohmmer's models.
Part # 9 the horizontal slide "slides" in dovetails on the top of the cabinet.
Part # 8 Vertical slide & sawframe also sits in dovetails on the Horizontal slide.

So my thinking is inside the cabinet there is an eccentric (referred to in the drawings) and obviously connected to the pulley.
That connects to a protrusion from the horizontal slide running down inside the cabinet using a connecting rod.
Therefore the whole deal; #9 & # 8 are moving back & forth "sawing"

Like Michael said the ratchet would allow the fore/aft action of the sawframe to advance the feed screw with each movement.

I have played with some pieces & parts and it seems feasible...............just now I need to build it, make it work and fit it inside the 1/2" cabinet!
Easy.

Marty

[granitechops]

Aw, cmon Marty, its not that small
by a quick guesstimate the base cabinet is 1/2"  x 1"  x 1"  in 1/16th           

For a man of your metal it will work!!

[lab-dad]

The base cabinet is .500" wide, 1.332" deep and 1.632" tall.

-Mj

[Chuck Doan]

The original CHB instructions call this a "No. 4 Q and C ".  Lots of power hacksaw videos on YouTube.

http://www.youtube.com/watch?v=Wcgm5iucqK4&feature=related  A Q and C No 1. No idea what it stands for.

[lab-dad]

You have an original?
Any chance of scanning me a copy of the instructions? (I know there isn't much).

"Q&C" = Quick & Cheap?

Thanks Chuck!!!!!!!!!!!
-Marty

[Chuck Doan]

Scan sent

[lab-dad]

Materials ordered.
Thanks to several emails (thanks! Chuck & Dave M. ) and attachments I am ready to move forward.
Stay tuned to this channel for more information as it becomes available.

-Marty

[EZnKY]

Looking forward to seeing it in action!

I love watching my Marvel cut.  Sometimes I just put scrap in it to watch the action, but don't tell anyone...