Pin Routers: The Old-School Production Workhorses

[RichterScale]

@Bruce Johnson
Is there still a neck milling/3D pantograph-type rig on deck? (I forget what you called it).
Really looking forward to seeing that.
I don't mean to be a PITA (it just kinda comes natural for me).

 

[Bruce Johnson]

@Bruce Johnson
Is there still a neck milling/3D pantograph-type rig on deck? (I forget what you called it).
Really looking forward to seeing that.
I don't mean to be a PITA (it just kinda comes natural for me).

Yes, I'm going to start building that soon. It's a pattern-following 3-D neck shaping machine. A complete separate machine, not a special fixture for the pin router. I'll write a different thread on it.

 

[Bruce Johnson]

I finished making the changes to the two Master Templates. Same old technique: drilled holes; rough sawed with the Ryobi Scroll Saw, then cleaned up with the 1/2" sleeve in the spindle sander. Here's the AMB-2M template with the corrected pickup cavity. You can barely see the glued-in MDF repair plug.

The two Master Templates.

Here's the AMB-2M template on top of the AMB-2 template, for a size comparison.

And I made the corrections on the two AMB-2M router templates. It took barely 10 minutes to do both of them.

Working away on the Big Green Machine, at 3 AM. I'm routing the first of the AMB-2 Routing Templates. What you see here is about 15 minutes of routing.

Oops. Made one mistake. Lesson learned: Remember to raise the pin up before starting routing! I'm learning how to use this machine. In many ways, it's similar to running a milling machine. You have to keep a good concentration on the sequence of switches, levers, wheels and pedals. A missed movement can ruin the job. I like running it by myself late in the night shift. I don't want interruptions.

 

[Chickenwheels]

There's a myth that Wal's old pin router is here in Sydney, Australia.

 

[Bruce Johnson]

There's a myth that Wal's old pin router is here in Sydney, Australia.

Heh, that's interesting. I can't imagine the shipping cost.

About 10 years ago, a huge old pin router from about 1910 appeared for sale here in the Los Angeles area. It was being offered for something like $100, the owners pleading to keep them from sending it to the scrap yard. It was a beautiful old curvy sculpture of cast iron, typical of machines of those days. They estimated that it weighed more than 4000 lbs. I agonized over it, but I couldn't rationally justify acquiring it. It probably got scrapped.

My Big Green Machine isn't that old; I think it's from the late 1970's. It's ITTM brand, made in Italy. Mike and I used to joke that it's the Ferrari of pin routers. Temperamental and expensive to work on, but when it's singing at full speed, it puts a big smile on your face. Just don't let it get away from you.

 

[coy garcia]

I finished making the changes to the two Master Templates. Same old technique: drilled holes; rough sawed with the Ryobi Scroll Saw, then cleaned up with the 1/2" sleeve in the spindle sander. Here's the AMB-2M template with the corrected pickup cavity. You can barely see the glued-in MDF repair plug.

View attachment 4258245

The two Master Templates.

View attachment 4258246

Here's the AMB-2M template on top of the AMB-2 template, for a size comparison.

View attachment 4258247

And I made the corrections on the two AMB-2M router templates. It took barely 10 minutes to do both of them.

View attachment 4258248

Working away on the Big Green Machine, at 3 AM. I'm routing the first of the AMB-2 Routing Templates. What you see here is about 15 minutes of routing.

View attachment 4258251

Oops. Made one mistake. Lesson learned: Remember to raise the pin up before starting routing! I'm learning how to use this machine. In many ways, it's similar to running a milling machine. You have to keep a good concentration on the sequence of switches, levers, wheels and pedals. A missed movement can ruin the job. I like running it by myself late in the night shift. I don't want interruptions.

View attachment 4258249

Awewome!!! Does this mean the bass building will commence

 

[Bruce Johnson]

Awewome!!! Does this mean the bass building will commence

Yes, I am about to start testing out all these fixtures and templates, and start building actual Scroll Basses!

 

[Beej]

I've been so enamored with this project, that I've been searching online for used pin routers. What I've found is that even an ancient beat up one is over $5000 CDN, and an inverted Onsrud like a few people have around here goes for around $2000 CDN. Cheapest I found was $1600 and it's not in good nick. I'll have to obsessively watch to see what's the lie of the land here...

 

[Bruce Johnson]

From 1995 to 2010, there was a flood of old surplus woodworking and metalworking machines for sale in the Los Angeles area. Many shops were closing down, or shrinking and upgrading to modern CNC machines. Thousands of big old machines were scrapped or sold off for $100 at auctions. Most of the ones sold were loaded on ships and headed to third world countries. A few crazies like me grabbed all we could afford. Now that market has nearly dried up. Only a small trickle of big old machines for sale today. I'm glad that I got my collection when I did. Many of my machines are very rare, and I may never see another one for sale.

The Big Green Pin Router is a rare one, particularly here in the US. I've never seen another one for sale.

Edit: Just after I wrote that, I dug through images of Pin Routers on DuckDuckGo, and found this one. It appears to be the exact same machine as mine, although it has a different brand name badge. Mint condition. It's an old picture from a machinery auction site some years back.

 

[Beej]

I sort of wondered if something like that were the case. I'll keep looking, as something in the neighbourhood of $1600 is not completely vomit-inducing, although I'll have to build another shed.

 

[TerribleTim68]

.... Now that market has nearly dried up. Only a small trickle of big old machines for sale today. I'm glad that I got my collection when I did. Many of my machines are very rare, and I may never see another one for sale....

Yeah, I hear ya' on this one. There's a 24" MAX Universal "Unimount 125" 3-hp disk sander for sale here in my local city, but he is asking $2k and there's just no way I can justify that in any world I've ever lived in.

 

[BTL]

The problem I discovered with big machines is they need big power. I had space at the home I sold last year, but only single-phase residential power to work with. The really heavy duty machines need three-phase commercial power.

 

[TerribleTim68]

The problem I discovered with big machines is they need big power. I had space at the home I sold last year, but only single-phase residential power to work with. The really heavy duty machines need three-phase commercial power.

There are solutions for that with transformers. I recently purchased a used shop vac from a guy a few blocks away and he had a full on commercial stamp press in his garage running on 208volt 3-phase through a transformer that sat in the corner of the garage.

 

[Beej]

The problem I discovered with big machines is they need big power. I had space at the home I sold last year, but only single-phase residential power to work with. The really heavy duty machines need three-phase commercial power.

Tis a very good point. I have 200 amp service, but yeah... don't think I can be running 3 phase anything in my home workshop

 

[Bruce Johnson]

Tis a very good point. I have 200 amp service, but yeah... don't think I can be running 3 phase anything in my home workshop

You can buy or build phase converters. I didn't have 3 phase power in my shop in Burbank. That didn't stop me from acquiring 3 phase machines! On smaller machines I usually changed out to single phase motors. But for some of the bigger machines, that wasn't practical. I bought a 3 HP rotary phase converter (the good kind) for about $400, and it ran those machines for years. When I moved to Fillmore, this building has plenty of 3 phase power. I sold the phase converter.

There are various types of phase converters available, and you can also build your own for pretty cheap.

And there are VFD's (Variable Frequency Drives). These are electronic speed controllers, which you can add to machines to make them variable speed. A side benefit is that the VFD's often run on single phase power, but they will power 3 phase motors. VFD's have come way down in price these days, and they are now a reasonable way to convert a 3 phase machine.

 

[Bruce Johnson]

It's been a busy couple of days, but I am making steady progress on the pin router tooling.

Yesterday I finished routing the pair of Routing Templates for the full size AMB-2 Scroll Bass bodies. I cut them completely on the pin router, and they took about 20 minutes each, going fairly carefully. Working at that speed, I'm estimating that it'll take me about 30 minutes to rout a walnut top and back set for an AMB-2 body. With the collar-routing, it's about 80 minutes. This is looking promising. And as I get more practice and work in batches, the time may come down more.

Now I have to finish up the permanent fixtures; the pair for the smaller AMB-2M and the pair for the full size AMB-2. I cut four rectangles of 3/4" Baltic Birch plywood, dressed their edges and started the layout....

 

[Bruce Johnson]

I finished up the four permanent routing fixtures: Top & Back for the full size AMB-2 and Top & Back for the smaller AMB-2M. Here's what they look like.

From the top side, it's a rectangle of plywood, with two 3/16" stainless pins sticking up. The walnut blank will have a matching pair of holes drilled in it, and will slip right down onto those two pins. They align it and hold it in place. For visual reference, I've traced the outline of all the pockets that this fixture will cut onto the top surface of the plywood. At the outer corners are the holes where the handles will bolt on.

On the underside is the MDF routing template. It's aligned with the same pins and attached with four screws. I can remove it if I need to modify or repair it.

Here are the four of them. Now I need to figure out some rack space to store them! And there will be more coming.

The last tooling components I need to make are the Masking Plates, one for each body size. I'll see if I can get them made tomorrow.

Then I'll be ready to start routing actual Scroll Bass bodies! First up is a pair of poplar blanks for the body of Ed's #018 AMUB-2.

 

[BTL]

@Bruce Johnson All of that looks great!

 

[Bruce Johnson]

Here's the first Mask Plate, for the AMB-2. It's a sheet of 3/4" MDF with the locating pin holes drilled in the opposite corners. Then I plugged it onto the AMB-2 Top routing fixture, and fired up the Big Green Machine. I pin routed all the way through all the chambers.

Here it is, pulled off of the fixture. I deliberately set the depth to go 1/32" into the surface of the plywood.

The Mask Plate plugs onto the pins on top of the wood body blank. I then rout down through it.

It has three purposes:

• By its weight, it presses down on the wood blank and helps make sure it doesn't lift up from the cutting vibration. If I see any problems with lifting, I can even add some little clamps to hold it down.
• The openings are a visual reference of where I'll be routing, to help me line up the fixture on the pin.
• I'll be writing notes in Sharpie around each opening to remind me what depth to cut each pocket.

The Mask Plate also flips over to work on the AMB-2 Back fixture. With its own notes on the other side.

Next up: Routing a real Scroll Bass body!

 

[boxerrider]

And there are VFD's (Variable Frequency Drives). These are electronic speed controllers, which you can add to machines to make them variable speed. A side benefit is that the VFD's often run on single phase power, but they will power 3 phase motors. VFD's have come way down in price these days, and they are now a reasonable way to convert a 3 phase machine.

I have about six machines with three-phase motors. Up to three hp a VFD is a great solution for phase conversion. Speed control with a turn of the dial is a plus on the drill press and shaper.

Enjoy!
Jeff