FS 19 to 23# Featherweight 36" Camelback Straight Edge. Rough casting or machined.

FS 19 to 23# Featherweight 36" Camelback Straight Edge. Rough casting or machined.

I have sold 5 of these to PMers (some pros and some neophytes) all by word of mouth and have one of a run of 6 left to sell. As cast it weighs 25#. But to get it flat and cleaned up, it machines to 23#. From there it is a matter of personal preference. I machined mine to 19 pounds which is probably the lower end of what most folks would want.

The sole measures 2 7/8" wide and 1/2" thick.

This is a camelback SE of my own design and commercially cast in 40 Grey Cast Iron.
It was allowed to cool slowly in the sand mold to reduce retained stress and then formally stress relieved by a heat treat firm per standard cast iron recommendations. They have had no hard spots and have reportedly scraped very nicely.

Though it is very light in weight compared to comparable broad-based 36" SE's, it is very rigid. I tested it to have less than .0001" deflection when supported at its ends and loaded with 30 pounds at its midpoint.

I can supply it as a rough casting or with the sole machined to +/- .001 flatness and the sides machined as well.

Local pickup would be ideal, though I have boxed and shipped one.

If interested, please PM or email me. I am considering doing another run if that seems indicated.

The pictures show a plywood, plastic pad, and brass grommet storage shoe I made for mine---not supplied but for illustration.

Price is 450 USD as cast and 625 USD machined. Shipping, obviously would have to be worked out depending on buyer needs.

Denis

I added a photo of the profile of the end of the SE and then posted again some photos of the casting.

A few more pics

If anyone is interested in the comments of a newbie scraper regarding dgfoster's 36" SE please see my post in the scraping section. Greatly appreciated Denis's machining of my SE (to better tolerance than I can hit with my machines over its 36"!) and easy to scrape. Thanks again Denis!

Regards,
Lucky7

Looks pretty good , have you considered adding pads to back (top) edge to add bolt on blocks so as it can be rested on its back to keep it clean between spotting cycles? My brown and sharp 5' has this feature and I like it. Have you considered development of a 4' and 2' as well ? Also I have a pattern for a larger square and box parallel that I made 30 yrs ago and would like to have them cast .

Lucky , I'm a new user to this with a tablet and it is not letting me respond to you . In answer to question of size . Square is about 30 inch tall 16 inch on base and 2.5 wide. I dug out the pattern a few weeks ago and took photos but have since replaced smarty pants phone with info and photos. Pattern for box parallel is a copy of Moore jig grinder made of aluminum. Approximately 10 x 4 x 5 if I remember correctly.

T-Cat, thanks for info. I'm interested in getting a iron square but more in the 8x16 by hypotenuse size so your pattern's bigger than I'd be up for. Good luck with your project though.

Regards,
Lucky7

T-CAT said:

Looks pretty good , have you considered adding pads to back (top) edge to add bolt on blocks so as it can be rested on its back to keep it clean between spotting cycles? My brown and sharp 5' has this feature and I like it. Have you considered development of a 4' and 2' as well ? Also I have a pattern for a larger square and box parallel that I made 30 yrs ago and would like to have them cast .

Click to expand...

T-cat,
I am thinking this post was directed to me.

Yes, I certainly did consider putting cast pads on the top as one sees this done quite often and in some ways they, at first glance, seem sort of clever. However I chose not to do this for several reasons.

1) Resting the camelback inverted and heavy side up on necessarily fairly narrow pads is an invitation to having it fall over and maybe, worse, fall off whatever it was resting on. This could do serious damage to the SE or your foot.
2) It is more convenient for me and anyone with rudimentary woodworking shills to nail together a simple 24 inch long by by 6" wide open u-shape resting frame. The base of that frame can be as wide as you like really so long as the upright legs are spaced wide enough to allow the SE to dropped in sole-side-up and have the sole engage the uprights. This provides a very stable and thus very safe support for the SE that is very unlikely to get bumped over. No worries about running the brayer up and down or side-to-side as needed to get your dye well and uniformly applied.
3) Those fist-sized knobs of added cast iron commonly used to make those supports add relatively useless weight. Easily 2 or 3 pounds. Who cares about 2 or 3 pounds? I do. After you hoist that SE 30 times against a vertical flat and transfer the dye, your arms are most likely going to start to notice. that is why I spent a lot of energy by design lowering my SE weight to 20# or so depending on how it is final machined.
4) If a person feels they just can not get by without those knobs, then just make some out of wood. (I know of at least one member here who is a professional woodworker and excellent machinist who made some very robust wood rests for the SE's he designed.) They weigh less than CI and can be removed if they interfere in a tight spot. They are no safer than CI knobs, however, But at least they are not a permanent "mistake " like cast ones would be. I actually made wood ones for mine, but found I liked the simple wood u-frame solution a ton (or maybe a pound and a half) better.
5) And least important, I think the knobs are sort of ugly. I wanted to design a SE that did not look ugly and was not unduly heavy. Those clunky heavy knobs just jut out of nowhere and destroy the lines. (If you say that is silly, fine with me.)

Denis

I have had a couple of inquiries about this and see mention has been made in another thread.

I have one available. More could be cast as the foundry is an hour away and the pattern is hanging on my shop wall.

Denis

dgfoster said:

to get it flat and cleaned up, it machines to 23#. From there it is a matter of personal preference. I machined mine to 19 pounds which is probably the lower end of what most folks would want.

The sole measures 2 7/8" wide and 1/2" thick.

Click to expand...

Very nice looking item, kudos!

I rather suspect several folks would be interested in what you did to get it down to only 19 lbs.

Just a short while ago, I weighed my 12" longer B&S 48", and was surprised it was but 21.4 lbs.

Mind - the sole is both thinner, and @ 2" wide, somewhat narrower - even including the dovetail projection - which presently is in an unfinished state.

I do not know if it left B&S Providence, RI that way or not. It has likely been machined and re-scraped at least once, if not more than once since new.

Monarchist said:

Very nice looking item, kudos!

I rather suspect several folks would be interested in what you did to get it down to only 19 lbs.

Just a short while ago, I weighed my 12" longer B&S 48", and was surprised it was but 21.4 lbs.

Mind - the sole is both thinner, and @ 2" wide, somewhat narrower - even including the dovetail projection - which presently is in an unfinished state.

I do not know if it left B&S Providence, RI that way or not. It has likely been machined and re-scraped at least once, if not more than once since new.

Click to expand...

Thanks for the kind words!

It was not difficult to reduce it from it max cleanup weight of about 23 pounds to a nicer to handle 19 pounds. The sole when cleaned up is a little over 1/2" thick which is thicker than needed. Cast iron weighs .284 pounds per cubic inch. By simply machining off 1/8" of thickness you take off 13+ cubic inches of material. Trim up the beveled and vertical sides of the sole and cleanup the bow with an angle grinder and file and there you are. If you really wanted to get even lighter, reduce the width of the sole on both sides and reduce it's thickness even more. But I was not going for record-setting weight, just what seemed a sensible compromise in weight while maintaining plenty of meat for many many rescrapes and for good durability.

The general achitecture of the ribs and bow was designed with an eye to not overbuilding the stiffening components of the SE. Making the cutouts simple circles and ribs thicker and square-sided simple rectangles would have made pattern building much simpler, but would have included a lot of dead weight.

Denis

dgfoster said:

Thanks for the kind words!

It was not difficult to reduce it from it max cleanup weight of about 23 pounds to a nicer to handle 19 pounds. The sole when cleaned up is a little over 1/2" thick which is thicker than needed. Cast iron weighs .284 pounds per cubic inch. By simply machining off 1/8" of thickness you take off 13+ cubic inches of material. Trim up the beveled and vertical sides of the sole and cleanup the bow with an angle grinder and file and there you are. If you really wanted to get even lighter, reduce the width of the sole on both sides and reduce it's thickness even more. But I was not going for record-setting weight, just what seemed a sensible compromise in weight while maintaining plenty of meat for many many rescrapes and for good durability.

The general achitecture of the ribs and bow was designed with an eye to not overbuilding the stiffening components of the SE. Making the cutouts simple circles and ribs thicker and square-sided simple rectangles would have made pattern building much simpler, but would have included a lot of dead weight.

Denis

Click to expand...

Actually.. the B&S ARE simple circles. OTOH, their ribs appear to be thinner, not thicker, and the back rib thinner as well, not just the sole.

I'll take a SWAG that thinwall gravity casting was understood by more experts in an era where foundries were more abundant and all sorts of common goods were cast in Iron every working day.

A really thinned-down camelback SE pattern today might run the risk of rather lower yield and higher net costs, never mind what automakers can accomplish with thinner wall engine blocks at their volumes, R&D spend, and degree of process control.

Monarchist said:

Actually.. the B&S ARE simple circles. OTOH, their ribs appear to be thinner, not thicker, and the back rib thinner as well, not just the sole.

I'll take a SWAG that thinwall gravity casting was understood by more experts in an era where foundries were more abundant and all sorts of common goods were cast in Iron every working day.

A really thinned-down camelback SE pattern today might run the risk of rather lower yield and higher net costs, never mind what automakers can accomplish with thinner wall engine blocks at their volumes, R&D spend, and degree of process control.

Click to expand...

The thickness of the bow, ribs, and webs of my Featherweight design were guided by the known minimums that are possible for reliably pouring cast iron. It may be true that there was more widespread general knowledge concerning casting iron in days of old, but there are still pockets of knowledge with decades of experience in casting. In the case of the foundry I use, the owner, metallurgist, foundry supervisor, and chief caster cumulatively have nearly 1.5 centuries of personal experience that they have acquired while learning from prior owner-operators and foundry workers. They all generously provided me guidance in determining what we could "get away with."

The minimum thickness issues face by B+S were the same and that is why their dimensions of rib and web thickness are no less and in some cases greater. Go thinner and too often a mold will pour short. As it is this occurs occssionally---the price you pay for pushing the envelope.

That said, using the same principles, I could make pattern for a 48 or 52" Featherweight with a similarly broad sole ( considerably wider than the B+S and thus allowing one reach under dovetail overhangs) that would weigh about 35 pounds or thereabouts. Problem is, there does not seem to be enough real money-on-table interest to justify the considerable work that goes into the fussy work of once again pushing the envelope to that end.

Denis

The wide sole reaches under a dovetail, but can it be used to actually spot a dovetail surface?

ewlsey said:

The wide sole reaches under a dovetail, but can it be used to actually spot a dovetail surface?

Click to expand...

I made the decision not to cast a prism edge into the base of my straight edge. That was based on the idea that when actually in use, dovetail spotting is only a small part of the use that a SE is likely to see. Tripling the thickness of the sole to make a prism would greatly increase the weight of the SE making the SE a pain to use all the time. In addition, using such an all-in-one tool to spot a dovetail would be clumbsy compared to spotting under the overhang and then truing the dovetail itself using a prism.

There are plenty of "boat anchor" all-in-one SE's that have already been made and there have been a number of narrow-sole (B+S as an example) SE's made that do not allow spotting under an overhang. The fun and challenge for me was to design a tool that would allow reaching under an overhang and not break your back or arms when used all day on a job as it would be the lightest possible practical design and would be aesthetically pleasing at the same time.

Denis

ewlsey said:

The wide sole reaches under a dovetail, but can it be used to actually spot a dovetail surface?

Click to expand...

In the case of the B&S - the tapered side of the sole doesn't project out very far. A mere 1/2". So perhaps not, realistically.

I'd observe that any dovetail that needed a 48" SE would probably be too tall and too deep for a surface that small to reach into and cover fully.

Likewise, any on-machine dovetail "shallow" enough that a 1/2" could fully cover would probably be on a machine far too short to need a 48" span - or even ALLOW getting it into place, even if the user would tolerate its awkward handling.

Regardless, I see merit in the prismatic shape.

Perhaps once length dictates stiffness vs mass as so essential that a Camelback reinforcement shape was needed, it should have a sole optimized for ONLY dovetails to keep the total mass down to "usable".

72" and up might be an example, lest a "solid" - or even a cored-out at backside - prism simply become too heavy to operate with for folks of ordinary body strength.

Which these days excludes ME, hence the Davidson Optronics collection - better yet - hiring younger men who are better scrapers as well as more fit.

I'm not an expert in large machine scraping, but it seems like the dovetail part can be dealt with using pretty crude scraping tools.

For example a Bridgeport table. One can scrape/grind the top and front of the table flat. Then these surfaces are a master to use when scraping the dovetail. Compare the dovetail surfaces to the master using micrometers, indicators, sleds, etc. One would only need some kind of scraping master to keep from digging a hole while scraping and maintain the angle of the dovetail along its length.

I know this is more or less how Devliegs are scraped. The machines have one dovetail and one straight way. Scrape the straight way using a master, then use that surface as a master to scrape the dovetail.

ewlsey said:

I'm not an expert in large machine scraping, but it seems like the dovetail part can be dealt with using pretty crude scraping tools.

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Not sure I'd say "crude" - just that there is not as much need of having references with as full a span. Easier to "piecemeal" a dovetail, just as you illustrate.

Or perhaps there is just enough less area, and greater tedium reaching into it that folks find more fussing about in the measuring of it becomes a smaller percentage of the overall task, and don't mind putting down the scraper and "shifting gears" as a bit of a break?

When you figure a 72" Devlieg has a dovetail at least 12 feet long, the chances of finding or successfully using a full length master are out of the question. And that's a fairly small Devlieg.

In the old days I'm sure the work was done with 4 or 6 foot masters and a set of levels for the flats and taut wire for the horizontal.

Today that could be done in a few minutes with a laser interferometer and a purpose made sled.

ewlsey said:

Today that could be done in a few minutes with a laser interferometer and a purpose made sled.

Click to expand...

True. And laser gear has been going cheap faster, and entering the market, new as well as used, far faster than optical did.

I may "obsolete" these uber-precise Davidsons before ever putting them to work with far cheaper CHINESE laser gear once I have a better idea what to look for.

Now "if only" the laser tech was also affordable enough to actually shape the surface, physical scraping, hand OR Biax, no longer required?

One can dream. Then try to live long enough dreams become affordable.

ewlsey said:

The wide sole reaches under a dovetail, but can it be used to actually spot a dovetail surface?

Click to expand...

Wes,
In many cases (but, definitely, not always) there is enough clearance to allow you using the dovetail straightedge upside-down (i.e. spotting the dovetail with the bottom of the straightedge.
As matter of fact, prismatic straightedges (i.e. not of camelback design) could be perfectly functional with only one side scraped-finished. You would need both sides scraped only if you want to spot both faces of the dovetail in a single spotting (i.e. spot the flat side, tilt it and spot the dovetail side).

Paolo