38 replies to this topic

[nzoomed]

Im looking at all the builds ive seen and i have no idea how people  would cut some of these shapes without a mill or laser cutter.

Ive only ever used a hacksaw and hand drill along with a file to cut out my parts, and its alot of work!

 

Now that laser cutting is so accessible and fairly well priced, im keen to draw up a few designs.

The bonus is that once you have a good design, you can cut out as many as you like and build a few in a fraction of the time.

 

If you dont have access to a CNC or laser cutter, how are most people cutting their chassis?

Because even with simple shapes, ive been finding it rather hard to cut my brass sheet which is about 1.5mm thick and ive pretty much just marked and cut out with a hacksaw and then filed the edges which means i need to allow for filing the material down in the process.

[havlicek]

A lot of parts...pans, center sections, nose pieces etc come with chassis kits to make building faster and easier.  I think that guys who hand-cut even steel pieces out of hard steel are few and far between now.

[nzoomed]

A lot of parts...pans, center sections, nose pieces etc come with chassis kits to make building faster and easier.  I think that guys who hand-cut even steel pieces out of hard steel are few and far between now.

ok i figured that may have been the case, although it appears more are getting into scratchbuilding from what I see.

 

I think laser cutting opens up alot more possibilities and it is fairly affordable where Im located.

Something I might play around with CAD when i get a chance.

 

For what Im doing, I think I could get away with a nice guillotine that can handle brass.

[havlicek]

To me (*and I'm strange), I think there is intrinsic value in producing...and then having something made entirely by hand.  Of course, I would include using a motorized hand tool ("Dremel") when I say something is "made by hand".  Now, certainly old builders used pre-cut pans and other pieces to speed things up, and maybe some even cut those, but just knowing the effort that went into building something is in itself worth something.  Some years ago, I built some chassis entirely out of cut up saw blades and piano wire...just because.  I would sometimes just make one piece, like a single pan and walk away because of how long it took.  Even filing that stuff pretty much didn't really work.  When a chassis was done, no one but me would know what went into it...and no one but me would probably care!    Still, I'd look at the thing and think..."yikes, I'm glad THAT'S over".  Then sometime later after my fingers had healed, I'd make another one.  In the end, I still wasn't "all that" as a builder, but the stuff I built had "me" all over it.

Point is, I don't think there's much you CAN'T do when building chassis without going CNC.  It all depends on how much time, effort and learning you're willing to put into it.  You may never be as precise as a computer-controlled machine, but I don't think that's really a problem.

[nzoomed]

To me (*and I'm strange), I think there is intrinsic value in producing...and then having something made entirely by hand.  Of course, I would include using a motorized hand tool ("Dremel") when I say something is "made by hand".  Now, certainly old builders used pre-cut pans and other pieces to speed things up, and maybe some even cut those, but just knowing the effort that went into building something is in itself worth something.  Some years ago, I built some chassis entirely out of cut up saw blades and piano wire...just because.  I would sometimes just make one piece, like a single pan and walk away because of how long it took.  Even filing that stuff pretty much didn't really work.  When a chassis was done, no one but me would know what went into it...and no one but me would probably care!    Still, I'd look at the thing and think..."yikes, I'm glad THAT'S over".  Then sometime later after my fingers had healed, I'd make another one.  In the end, I still wasn't "all that" as a builder, but the stuff I built had "me" all over it.

Point is, I don't think there's much you CAN'T do when building chassis without going CNC.  It all depends on how much time, effort and learning you're willing to put into it.  You may never be as precise as a computer-controlled machine, but I don't think that's really a problem.

I completley agree, I think its something that will add value to alot of vintage scratchbuilt chassis in future. I see there are a few collectors out there.

I like doing things by hand also, but at the same time I wouldnt mind making use of technology thats available.

I certainly found my dremel useful and the cutting discs come in handy at times.

Perhaps im using the wrong material and/or tools, but ive found brass extremely hard to cut and drill, even your file gets clogged quick with the stuff.

Really need to order that DVD ive seen advertised here

[havlicek]

 

Perhaps im using the wrong material and/or tools, but ive found brass extremely hard to cut and drill, even your file gets clogged quick with the stuff.

Really need to order that DVD ive seen advertised here 

 

The ace scratch-builders can offer a lot of advice, so they would be the ones to question.  On the cutting discs, the fiber reinforced ones last a stupid-long time, but because of how thick the kerf they cut is, they take forever to cut stuff.  The thin cutoff discs work MUCH better, but you need to be really steady with your hand, because they will break if you look at them crosswise.  Brass is difficult to cut this way, but aluminum is even worse.  ***Sometimes, you can just score brass enough to be able to finish it by holding it down securely with something hard, strong and straight while the cut piece hangs off your work surface and you gradually wiggle it up and down the break off the piece.  It's then easy to finish it off with a file.  I think a big problem is with trying to work fast.  Also, it's almost always a good thing to not cut right to the line, and then finish off to the line with a file.  You can also either file the piece while holding it in a vise...OR... hold the file on your work table and play the piece against the file.  Different ways of working depending on the cut you want to make come with experience.  The top-shelf chassis builders do all this stuff automatically...they look at a cut and pretty much know what to do.  

Oh and...sometimes you want to make the cut by holding the piece steady and moving the tool.  Other times you want to hold the tool steady and move the piece.  Then again, oftentimes you can better make long straight cuts by using a piece of a harder material as a guide on top of the brass piece and cutting "against" the guide piece.

After all that...there's the whole mess involved with becoming an ace at soldering, and jigging things-up to hold them while you solder.  GAK!  Now you know why I don't build chassis anymore. 

[Bill from NH]

Things you can try when drilling brass,  use a metalworking compound (paste) such as ROCOL R.T.D. or a liquid such as Tap Magic Cutting Fluid. When using the thin (Dremel & other brands) cutoff discs, try doubling them up on the arbor and/or soaking them in ATF. As John said  above, a hard straightedge makes a good cutting guide. I use the back edge of a bi-metal hacksaw blade.

[Richard G With]

Since you are cutting brass sheet, I assume you're making retro chassis parts?

One reason that CNC and laser cutting are not widely used by individuals is that it's not allowed under IRRA rules.

But it isn't all that difficult to make things like nose pieces, pans and torsion plates with a pattern and practice.

Perhaps Cheater could enlighten us on what it takes to get components or kits legalized for IRRA?

[Dave Crevie]

The Elmhurst library has what they call their "Maker Space". They have three CNC laser cutters, one does metal. They also

have a small CNC router that can do metal, but no flood cooling. They have three FDM 3-D printers, and I believe 10 computer

workstations with 3-D modelling software. They have classes in basic CAD for kids starting at 5 years old. 3-D printing classes

starting at 5th grade. All free to Elmhurst residents with valid library card. And, oh yeah. They have all that in classes geared

towards us seniors. ( All payed for through my property taxes. The library has the second largest budget, second only to the

school district.)     

[Half Fast]

The IRRA rule on chassis parts is as follows:

 

2b. Chassis parts, such as pans, brackets, guide
tongues, etc., that are made using EDM, laser,
or water-cutting techniques are allowed only if
they are individual commercially-available
components or components of chassis kits (i.e.
these techniques may not be used in the private
manufacture of one-off components that are not
commercially available).

 

Cheers

[James Wendel]

The Elmhurst library has what they call their "Maker Space".

 

Wow, Dave that sounds amazing.  What state is Elmhurst in?

[elvis44102]

when working with brass we also used a nibbler...and tin snips for thin brass....dremel cutting spring steel requires lots of patience it generates much dust AND you have to watch the heat so as to not overheat part lol

[nzoomed]

 

 

Since you are cutting brass sheet, I assume you're making retro chassis parts?

One reason that CNC and laser cutting are not widely used by individuals is that it's not allowed under IRRA rules.

But it isn't all that difficult to make things like nose pieces, pans and torsion plates with a pattern and practice.

Perhaps Cheater could enlighten us on what it takes to get components or kits legalized for IRRA?

Yes we are mostly into retro racing on our 1/32 scale track.

I thought most scratchbuilders are using brass still going by the builds ive seen posted. I probably need a definition of "retro" because i still see modern chassis made from brass such as a parma international 32. Are all scratchbuilds considered "retro"?

 

My question is how would you even be able to prove if a piece is laser cut unless its some ridiculously complex shape? Any ultra clean edges could be gone over with a file a bit to hide any signs of milling or laser cutting.

Not that it affects me anyway, because I only race on our home track and am not racing competitively, but i can see reasons why there are rules on it.

 

No reason why a new class of car could not be raced that is strictly CAD built anyway.

 

For me its just a time saving thing, but I do like the skill involved in making something by hand. Even using CNC cut pieces its still a fair bit of work in assembly though.

 

 

The ace scratch-builders can offer a lot of advice, so they would be the ones to question.  On the cutting discs, the fiber reinforced ones last a stupid-long time, but because of how thick the kerf they cut is, they take forever to cut stuff.  The thin cutoff discs work MUCH better, but you need to be really steady with your hand, because they will break if you look at them crosswise.  Brass is difficult to cut this way, but aluminum is even worse.  ***Sometimes, you can just score brass enough to be able to finish it by holding it down securely with something hard, strong and straight while the cut piece hangs off your work surface and you gradually wiggle it up and down the break off the piece.  It's then easy to finish it off with a file.  I think a big problem is with trying to work fast.  Also, it's almost always a good thing to not cut right to the line, and then finish off to the line with a file.  You can also either file the piece while holding it in a vise...OR... hold the file on your work table and play the piece against the file.  Different ways of working depending on the cut you want to make come with experience.  The top-shelf chassis builders do all this stuff automatically...they look at a cut and pretty much know what to do.  

Oh and...sometimes you want to make the cut by holding the piece steady and moving the tool.  Other times you want to hold the tool steady and move the piece.  Then again, oftentimes you can better make long straight cuts by using a piece of a harder material as a guide on top of the brass piece and cutting "against" the guide piece.

After all that...there's the whole mess involved with becoming an ace at soldering, and jigging things-up to hold them while you solder.  GAK!  Now you know why I don't build chassis anymore. 

Yes very true, the dremel can be a lifesaver. alot of observations youve made are the same for me.

I had thought of making a jig up with a sheet of teflon and it appears that the "ricks" jig is just that!

Some people are using quartz benchtop sheeting for their jigs also. Holding pliers, soldering iron and solder requires 3 hands, very difficult. But im sort of used to this as i do lots of this kind of work.

 

Things you can try when drilling brass,  use a metalworking compound (paste) such as ROCOL R.T.D. or a liquid such as Tap Magic Cutting Fluid. When using the thin (Dremel & other brands) cutoff discs, try doubling them up on the arbor and/or soaking them in ATF. As John said  above, a hard straightedge makes a good cutting guide. I use the back edge of a bi-metal hacksaw blade.

The hacksaw blade idea is good, thankfully most the the shapes i cut out are mostly rectangular, but cutting a thick sheet with a hacksaw is very slow going and you have the problem with the blade wandering and cutting unevenly so you have to always allow for extra and file down.

[Bill from NH]

Shaun, you don't use the hacksaw blade for cutting the brass.  You use it as a hard metal ruler(straightedge) to run your spinning cutoff discs against. I don't know what you consider 'thick' to mean, but you'll never cut 1/16" sheet brass in a single pass using a rotary tool with a cutoff disc.

[nzoomed]

Shaun, you don't use the hacksaw blade for cutting the brass.  You use it as a hard metal ruler(straightedge) to run your spinning cutoff discs against. I don't know what you consider 'thick' to mean, but you'll never cut 1/16" sheet brass in a single pass using a rotary tool with a cutoff disc.

Yes I was agreeing with you about a hacksaw blade for a guide and I think you misunderstood what I was saying, as i was just commenting on how difficult it is to cut the stuff with a hacksaw which is what i presently have been doing. But using the blades as a guide for a file or cutting disc is a great idea and would stop any damage from the jaws of the vice also.

[Mike Patterson]

I remember an article from BITD where someone used a drawer slide with a Dremel bolted to it to make the long cuts on steel center sections.

[Bill from NH]

Mike, I remember  that same steel cutting jig. I use to have a link for it, but don't know if I still do. It's post #16 in this thread,    http://slotblog.net/...hassis-i-built/

 

Shaun, if you're damaging your brass on the vise jaws, line them with something soft that cushions, such as tape, rubber, or even thin wood.

[slotbaker]

Yes we are mostly into retro racing on our 1/32 scale track.

I thought most scratchbuilders are using brass still going by the builds ive seen posted. I probably need a definition of "retro" because i still see modern chassis made from brass such as a parma international 32. Are all scratchbuilds considered "retro"?

Short answer to that question is, no. People build all sorts of scratchbuilds, for many different reasons.

 

Shaun, when the guys here (and elsewhere) talk about "Retro" they are usually referring to classes of car that developed and grew out of a concept called "D3", created by Paul Sterrett (RIP) back in 2005-06.

There are specific rule sets published by each of the racing groups, so there are definite doos and don'ts, if you want to participate in any of their events.

 

There is nothing stopping anyone from coming up with their own set of regs for any class, so if you have enough builders/racers to support your specific class, go for it.

 

edit:
Click here to check out various Retro groups.

[slotbaker]

I'm an old toolmaker doing my trade in the late '60s, and did quite a bit of hand cutting of sheet metal with Abrafiles (Wire saws). (Check some of the youtubes. They mainly show cutting wood, but there are metal cutting versions to.)

For small quantities, EDM, waterjet, or most other CNC type processes are relatively expensive and time consuming.

You pretty much have to make a drawing in any case.

If you make the drawing on a piece of brass sheet, drill any holes, pick up your abrafile then start cutting.

About half hour to an hour, you can have the part cut out, then clean it up with a file.

Of course, the more you do the better you get.

If you wanted a quantity, then sure, CNC will be the way to go.

It depends greatly on what facilities you have access to, and how much hand work you want to do.

Personally, cutting sheet brass with a dremel, is for the birds.  Give me an Abrafile or Jeweller's saw any day.

[nzoomed]

I'm an old toolmaker doing my trade in the late '60s, and did quite a bit of hand cutting of sheet metal with Abrafiles (Wire saws). (Check some of the youtubes. They mainly show cutting wood, but there are metal cutting versions to.)

For small quantities, EDM, waterjet, or most other CNC type processes are relatively expensive and time consuming.

You pretty much have to make a drawing in any case.

If you make the drawing on a piece of brass sheet, drill any holes, pick up your abrafile then start cutting.

About half hour to an hour, you can have the part cut out, then clean it up with a file.

Of course, the more you do the better you get.

If you wanted a quantity, then sure, CNC will be the way to go.

It depends greatly on what facilities you have access to, and how much hand work you want to do.

Personally, cutting sheet brass with a dremel, is for the birds.  Give me an Abrafile or Jeweller's saw any day.

Never heard of an abrafile before! Looks essentially like a coping saw, i think something like this would be very useful, will see if i can get one locally

 

Short answer to that question is, no. People build all sorts of scratchbuilds, for many different reasons.

 

Shaun, when the guys here (and elsewhere) talk about "Retro" they are usually referring to classes of car that developed and grew out of a concept called "D3", created by Paul Sterrett (RIP) back in 2005-06.

There are specific rule sets published by each of the racing groups, so there are definite doos and don'ts, if you want to participate in any of their events.

 

There is nothing stopping anyone from coming up with their own set of regs for any class, so if you have enough builders/racers to support your specific class, go for it.

 

edit:
Click here to check out various Retro groups.

OK, that helps alot. I had no idea what it meant!

I thought retro racing was racing vintage slotcars!

[Paul Lindewall]

The IRRA rule on chassis parts is as follows:

 

2b. Chassis parts, such as pans, brackets, guide
tongues, etc., that are made using EDM, laser,
or water-cutting techniques are allowed only if
they are individual commercially-available
components or components of chassis kits (i.e.
these techniques may not be used in the private
manufacture of one-off components that are not
commercially available).

 

Cheers

 

I would like to know how that rule could be enforced. If you showed up with a new part (i.e.: pan) that was laser cut, how could they prove that you didn't just cut it by hand very accurately? 

[Dave Crevie]

Elmhurst is a suburb of Chicago, Illinois. The Maker Space is free to residents, but for non-residents there is an hourly

charge. It could get expensive if you have a large project. It came to be for two reasons. The library needed a cash

generating service. The board did a study of some libraries in Europe, and decided that it could be successful in that

regard. It was also seen to be incentive for the school board to re-instate the industrial arts program, which was

dropped mostly because the new, higher income people could not accept that their kids might become factory workers.

They thought activities like lacrosse and water polo were more in line with their station in life. Anyway, the Maker Space

has been self-supporting, so I pushed to get the CNC equipment added when it came up at a "Friends of EPL" meeting. 

(thought I might make use of it myself) 

 

 Scan_0018.pdf   524.81KB   92 downloads

[James Wendel]

Thanks for the reply, Dave.  It sounds like a very cool program.

[slotbaker]

Never heard of an abrafile before! Looks essentially like a coping saw, i think something like this would be very useful, will see if i can get one locally

Coping saw blades are thin, and flat with teeth on one edge, like a hacksaw blade, but very narrow to allow the blade to cut tight, curved shapes.

 

Abrafiles are round with teeth all the way around, which allows the blade to be used in any direction.

They are also known as Rod Saws because they are round.

 

The Abrafile blades are used with a std hacksaw frame, using adaptors like these.

[nzoomed]

Coping saw blades are thin, and flat with teeth on one edge, like a hacksaw blade, but very narrow to allow the blade to cut tight, curved shapes.

 

Abrafiles are round with teeth all the way around, which allows the blade to be used in any direction. They are also known as Rod Saws because of this.

 

The Abrafile blades are used with a std hacksaw frame, using adaptors like these.

Yeah i could see that, essentially its a coping saw with a round file like wire blade. I actually was wondering if anything like that existed, ive never seen them at our tool shops but will ask around, i dont see any retailers stocking them and there is not even any listed on ebay, so im assuming they are not overly common.

Im assuming they come in different thickness and coarseness?