I bought the exact end mill from tnutz for my 10 and 15 series. But as you note, they are 2 flute flat end mills - really made for CNC mills or maybe a drill press.

Given the exact placement of the anchors, maybe try to create some jig that you can clamp the end of the 8020 into which then gives you decent work holding to use a drill press - and provides perfect placement. No need for pilot then.

Reminds me I need to clean out the CNC mill - been doing a fair number of anchors for the final 8020 wall.

 

Not Playing Fair.

 

I'm planning to use some anchor fasteners in the new van (and maybe retrofit to the old van) and I'm having a hard time finding the necessary 20mm counterbore drill-bit that includes a pilot.

I'm finding plenty of flat / counterbore bits in the correct size, but I don't expect them to work too well without a pilot (even with a drill press). And I'm thinking I need a long enough pilot bit to bite into the middle section of the extrusion - so I'm unsure if basic 2-step bits will work.

Anyone point me in the right direction? The 8020 site doesn't even list one for 30-series. I /think/ it's the same as 40 series, though. But theirs don't use pilots.

Using's a Counterbore without a pilot on a drill press will not work well, also using a Counterbore without a pilot on a milling machine will also not work well, A End mill will not work well on a Drill press (to much play in the spindle bearings)


McMASTER-CARR "Changeable Pilot Counterbore's"

You will need to make a custom Pilot, the standard Pilot's are 1 to 1 diameter to length ratio (guide part), the part of the pilot that fit's into the counterbore is a reduced diameter, made from HSS (very hard)

Use "High Speed M2 Tool Steel" (McMASTER-CARR) for the guide pilot. Use as a single diameter guide pin, no step in the diameter. if needed open up the guide hole diameter after.

The guide pilot will have alot of stick out and it's a interupted cut, not ideal, but should work OK.

might consider Reaming the guide hole, .001-.003 clearance on the guide pin would be ideal, typical hole size drilled with a drill press can be .005-.010 oversized. YMMV, drill .010-.015 undersize then ream. the closer fit will on the guide pin help the Counterbore to cut On size.

Years ago I did some Counterbore's on 80/20 using a Bridgeport type mill with a end mill. I have No experience doing this on a drill press. (pinch of Salt)

 

A 25/32 counterbore for use with interchangeable pilot is really close to 20mm (.006" smaller) so might possibly work.

25/32x7/8 HSS 1/4" SHK.DIA. AIRCRAFT COUNTERBORES-PITTSBURG ITEM NO. 2235050(FT) | eBay

25/32x7/8 HSS 1/4" SHK.DIA. AIRCRAFT COUNTERBORES-PITTSBURG ITEM NO. 2235050(FT). Aircraft Counterbores & Spot Facers -. It em is in new and unused condition. Ruler NOT included if shown. Used only for accurate viewing and sizing .

www.ebay.com

25/32 HIGH SPEED STEEL STRAIGHT SHANK INTERCHANGEABLE PILOT COUNTERBORE 500 | eBay

25/32 HSS Interchangeable Pilot Counterbore. Pilot Hole Size: 1/4.

www.ebay.com

25/32 HIGH SPEED STRAIGHT SHANK COUNTERBORE 144-00050-2 | eBay

Ruler NOT included if shown. Used only for accurate viewing and sizing .

www.ebay.com

You would have to also buy the correct pilot for whatever size pilot hole you were planning. You would have to first drill a pilot hole then do the counterbore. The interrupted cut is not ideal using a drill press. Might do ok since it's just aluminum though. If I was going to try a drill press, I would get the one with 5 flutes assuming your chuck is big enough to fit the shank.

 

I'm planning to use some anchor fasteners in the new van (and maybe retrofit to the old van) and I'm having a hard time finding the necessary 20mm counterbore drill-bit that includes a pilot.

I'm finding plenty of flat / counterbore bits in the correct size, but I don't expect them to work too well without a pilot (even with a drill press). And I'm thinking I need a long enough pilot bit to bite into the middle section of the extrusion - so I'm unsure if basic 2-step bits will work.

Anyone point me in the right direction? The 8020 site doesn't even list one for 30-series. I /think/ it's the same as 40 series, though. But theirs don't use pilots.

no - 30 series and 40 series connectors are different size.
30 series anchor cam is 15.7mm dia .... so a 16mm hole (or maybe 5/8"= 15.875mm)
but as you point out neither of those sizes countebore in their catalog - odd
40 series anchor cam is 19.93 mm dia and they sell a 20mm countebore for that size
also bolt sizes are different - m6 vs m8

IIRC @chicagoandy ?? has had some sucess with a forstner bit in a drill press.

I cannot for the life of me, I cannot find the site online where I saw a diy fixture out of 8020 to use plunge a router
Found it! LINK Concept seems good but those stops for the router seem too fiddly and router not locked down NG. I'd eliminate them a bolt the router base directly to the fixture that holds the extrusion (or use an intermediate plate if necessary) which should be more precise. Similar concept could also be used on a drill press ... in line with @OldChubbyKnuckle guidance.

Can't provide any strong rationale, but I have a hunch that with a good setup a router might work better than a drill press?
Dunno if counterbore or forstner would work better withsuch a setup

 

I just use a drill press with a guide that I built to hold the 8020 still out of wood. Basically just a channel.

Often I will drill a pilot hole but larger stuff, but mostly have been doing this with 1010, so not as big of a problem.

Then drill a hole straight through the web using a normal drill bit for aluminum from McMaster.

I don't bother with a counter bore - I just use a bolt and washer. It isn't that difficult to eyeball it and come out reasonably close if you wanted to do that.

If you mark the holes location all across the piece before starting, it isn't that hard to line up.

That particular drill press is just a table top that I just keep set up for 8020 so nothing moves ( at least on purpose )

This is all done by hand with #10.

 

Reconsider the need for machined connectors.

I used DIY flatbar or angle connectors with series 15 on both of my builds with 5/16" carriage bolts and elastic stop nuts. Have never needed to retighten a connector on either build and never had any joint failure. Sprinter owned for 6 years and Transit for almost 10. Based on my experience machined connectors are not required in a conversion. Did use internal angle connectors that use set screws initially in Sprinter build and they did loosen due to small contact point of set screw. Replaced internal connectors due to issue.

In order to use carriage bolts with a 1 1/2" angle connector the holes must be 1" from the angle apex for nuts to clear.

Suspect that using this method on series 10 may be a problem due to shorter extrusion width. Did not use series 10 in either build so no knowledge about how well it would or would not work.

Using 80/20 | Orton Travel Transit

 

I had some success with forstners, but yeah, a pilot mill does work a lot better. If I'd known about those back then I would have skipped the forstner talk.

Here's a great site for pilot mills: https://www.mscdirect.com/product/details/08790511 That category 'interchangable pilot' is great, you can pick the mill-size you want, then go find the 'add-on' pilot in the size you want. They mostly only have fractional inches, so maybe 51/64, which is 20.24 mm.

Here's an actual 20mm mill, but the pilot is probably too big? https://www.fleetpride.com/parts/keo-power-tool-accessory-44850683

All that said... one reason I stopped playing with Forsters is that I discovered their t-matic connectors. I use a lot of t-matic connectors now. They are a bit pricey, but man are they easy to work with.

 

no - 30 series and 40 series connectors are different size.
30 series anchor cam is 15.7mm dia .... so a 16mm hole (or maybe 5/8"= 15.875mm)
but as you point out neither of those sizes countebore in their catalog - odd
40 series anchor cam is 19.93 mm dia and they sell a 20mm countebore for that size
also bolt sizes are different - m6 vs m8

I bought the anchors from McMaster... and the lobe is 20mm diameter. Hm. 🤔

Well, that's interesting. The McMaster website even says 20mm "installation hole" for 30, 40, and 45mm rails. Must be different than the 8020 ones? Strange.

IIRC @chicagoandy ?? has had some sucess with a forstner bit in a drill press.

Interesting. I'd expect that to go dull in a couple cuts...

I cannot for the life of me, I cannot find the site online where I saw a diy fixture out of 8020 to use plunge a router
Found it! LINK Concept seems good but those stops for the router seem too fiddly and router not locked down NG. I'd eliminate them a bolt the router base directly to the fixture that holds the extrusion (or use an intermediate plate if necessary) which should be more precise. Similar concept could also be used on a drill press ... in line with @OldChubbyKnuckle guidance.

Can't provide any strong rationale, but I have a hunch that with a good setup a router might work better than a drill press?
Dunno if counterbore or forstner would work better withsuch a setup

It sure seems like a counterbore with a decent pilot /should/ work... but that is an elaborate thingy to make it work with the router!

 

I bought the anchors from McMaster... and the lobe is 20mm diameter. Hm. 🤔

Info I provided above regarding the anchor dia is from the drawings on 8020.net

Note the 16.51mm dimension called out on the drawing for 30 mm extrusion and 20.57mm on 40mm extrusions. Perhaps the diameters on the anchor cams (why are the called cams?) may be intentional.

Just a guess that taking out the meat into the corner of the extrusion is not an issue regarding fastener strength cuz not on axis of bolt clamping force. Still a lot of metal between the between the hole and the end of the extrusion .... BUT ... it MAY comprise the strenght of the slots that would be uses for making other connection at a right angle to that anchor .... MAYBE. 🤷‍♂️

Looks like the size of the t-nuts on the 30 series and 40 series anchors are also different sizes ... you know, to match the different slot sizes. As well as the aformentioned different size bolts.

I'd check the t-nut fit before even think drilling a 20mm hole. Sure seems like a 16mm bit and some 30 series conectors are the way to go.

Yea looks like McMaster is calling that out for 40mm extrusions.
McMaster-Carr

 

I just use a drill press with a guide that I built to hold the 8020 still out of wood. Basically just a channel.
...

This is not with, "anchor connectors," right? They're a specific type of connector that requires a specific machined hole.

Reconsider the need for machined connectors.
...

Pretty sure you're not following that this is one of many types of connectors for 8020 stuff. And the two that require machining are around three times stronger than the standard corner brackets but have the advantage of leaving clean connections.

I used some of the "inside corner connectors," (the ones you reference) to achieve the same clean look (and easier to do cabinet doors and such) on the last van before realizing that the machined connections are about twenty times the strength of those connectors.

I'll be using a mix of all of them - as applicable. Nothing is easier than the standard corner brackets you used; they'll be used. But the overall strength-relevant connections will be machined this time. And I'll likely even use those super-weak corner brackets in some cases - where strength doesn't matter.

I had some success with forstners, but yeah, a pilot mill does work a lot better. If I'd known about those back then I would have skipped the forstner talk.

Here's a great site for pilot mills: https://www.mscdirect.com/product/details/08790511 That category 'interchangable pilot' is great, you can pick the mill-size you want, then go find the 'add-on' pilot in the size you want. They mostly only have fractional inches, so maybe 51/64, which is 20.24 mm.

Here's an actual 20mm mill, but the pilot is probably too big? https://www.fleetpride.com/parts/keo-power-tool-accessory-44850683

All that said... one reason I stopped playing with Forsters is that I discovered their t-matic connectors. I use a lot of t-matic connectors now. They are a bit pricey, but man are they easy to work with.

I'll have to look again at the T-matic connectors. Right now, I'm just testing how much hassle each connector will be to install. I expect to use more of the basic end-connectors - less machining and even stronger than the anchors.

I've got a 2-step bit coming that's 12/20... I'm not confident that will work, but I'm going to try it.

Maybe a countersink would even work? If it's shallow enough angle? 🤔

 

This is not with, "anchor connectors," right? They're a specific type of connector that requires a specific machined hole.



Pretty sure you're not following that this is one of many types of connectors for 8020 stuff. And the two that require machining are around three times stronger than the standard corner brackets but have the advantage of leaving clean connections.

You are correct, I don't have the ability to hold that kind of tolerance and like the gussets much better. It depends on the project goals of course.

 

picture of 5/8 (.625) diameter counterbore, this one has a pilot shank dia. of .125, McMASTERCARR lists 2 .625 dia. CB, .125 dia. pilot and .188 dia. pilot. I would opt. for the larger pilot for increased stiffness.

 

I tried creating my own anchor fastener holes on 10-series 8020 using the Tnutz 2-flute end mill in my drill press, and it did not go very well. I built a jig with 8020 as mentioned above, but it did not help much. There was WAY too much slop in the quill of my drill press. The end mill wandered significantly, resulting in a hole that was severely oval shaped. Oddly, this setup cut just fine until the very last 1/16" of depth. I couldn't figure out why the last little bit of depth caused all the trouble. I was able to use anchor fasteners in the holes and make the connection needed, but I intend to replace it when I place my next Tnutz order.

empty jig on the drill press

getting ready to start milling the anchor fastener hole

 

Pretty sure you're not following that this is one of many types of connectors for 8020 stuff. And the two that require machining are around three times stronger than the standard corner brackets but have the advantage of leaving clean connections.

I used some of the "inside corner connectors," (the ones you reference) to achieve the same clean look (and easier to do cabinet doors and such) on the last van before realizing that the machined connections are about twenty times the strength of those connectors.



I assumed you were referring to the "anchor fasteners" I have seen many here use. Part # 3360 for 15 series. What is the part number for the second machined connector?

The internal connector part # 3364 is the one that failed in the Sprinter build. The set screws did loosen due to the small set screw point contact area. Maybe they would work if installed with Locktite? I replaced them with DIY angle connectors.

My experience with simple cheap DIY angle and flat bar connectors has been positive. No issues when used with carriage bolts. I do understand that the machined connections are much stronger than what I did. The question is if that stronger connection is necessary in our van conversion applications?

People also use a variety of nuts in the slot to obtain a treaded hole. I found that the inexpensive two and three hole "economy T-nuts" work better than the other more expensive choices. With two hole economy nuts I put a bolt in one of the holes to give me a "handle" to move the nut in the slot to where I want it. Once located a set screw in the second threaded hole locks nut in place. Makes adding a threaded hole in vertical extrusions much easier than single nuts. The three hole economy nut is used where I need two bolts to keep the attached part from rotating. Set screw in center hole. Disadvantage is you must have access to extrusion end to insert the nuts.


[/QUOTE]

 

picture of 5/8 (.625) diameter counterbore, this one has a pilot shank dia. of .125, McMASTERCARR lists 2 .625 dia. CB, .125 dia. pilot and .188 dia. pilot. I would opt. for the larger pilot for increased stiffness.
...

Super helpful, @kazuo. I think part of my problem is that I was HOPING to find a single counterbore with the pilot bit built in - so I'm not drilling twice. Any insight why the separate-pilot setup might be more common / superior?

I tried creating my own anchor fastener holes on 10-series 8020 using the Tnutz 2-flute end mill in my drill press, and it did not go very well. I built a jig with 8020 as mentioned above, but it did not help much. There was WAY too much slop in the quill of my drill press. The end mill wandered significantly, resulting in a hole that was severely oval shaped. Oddly, this setup cut just fine until the very last 1/16" of depth. I couldn't figure out why the last little bit of depth caused all the trouble. I was able to use anchor fasteners in the holes and make the connection needed, but I intend to replace it when I place my next Tnutz order.
...

That's exactly what I'm expecting without a pilot. And that's the exact drill-press I have, so... likely identical experience.

Hm... leading me more and more toward just the end-connectors and/or try the new T-matics. 🤔

I assumed you were referring to the "anchor fasteners" I have seen many here use. Part # 3360 for 15 series. What is the part number for the second machined connector?

Correct. That is the, "anchor connector." These are the, "end fasteners," I mentioned: they require an access hole (no precision, really) and threading the center of the extrusion. But they're similar strength to the anchors.

The internal connector part # 3364 is the one that failed in the Sprinter build. The set screws did loosen due to the small set screw point contact area. Maybe they would work if installed with Locktite? I replaced them with DIY angle connectors.

I used a bunch of those on our Sprinter (in 20mm and 30mm) then used a bunch on the Transit (30mm) and started using a dab of Loctite... then realized that they shouldn't need Loctite if the mechanism were working correctly (bending the arms of the slot) - thus realizing they weren't working as intended. Then I had a couple break. Then I saw the chart on just HOW weak they are (like 50 pounds break point) and I'll only use them for intermediate connectors with no strength expectation.

My experience with simple cheap DIY angle and flat bar connectors has been positive. No issues when used with carriage bolts. I do understand that the machined connections are much stronger than what I did. The question is if that stronger connection is necessary in our van conversion applications?

Agreed. No issues for me, either. But they make flush panels look crappy and difficult to cut.

I figured they were plenty strong - and perhaps they are - until seeing how much stuff in my brother's van looked like a child pulled apart their Legos after the accident.

Basically, I'm trying to do EVERYTHING more solid in this van. As much as I tend to take my own life in my hands - not just driving but climbing, trail-running, split-boarding, more - and I'm pretty cavalier with my adult sons' lives... I find I am a bit of, "not good enough for my grandsons' lives," on this now. The babies are both under two years old and I'm suddenly asking myself, "how can I make things MORE safe/secure," in ways that I previously wouldn't have done.

So, I'm exploring the alternative connectors for everything in this van - not just the 8020 stuff. The seat was expensive and it took a lot of work to get it really secured but I'm MUCH more confident in the safety of the seat - and I'll be putting the same one in the old van - using the same method. The bed is through-bolted more solidly than the last van. The fridge/freezer are through-bolted, unlike the old van. I don't know how everything will end up being done - I've already gone BACK on some ideas as just not being worth the effort - but I'm exploring options and trying to lean more toward, "how well/strong/safe can I reasonably do this?" than previously.

Sometimes, think it's just that I'm getting old... but I still see it as valuing my own life so much that I have to live it aggressively - like the young idiot I must still be at some level. But the protection I've felt for my wife - which was never quite as strong toward my boys - seems to be turned UP when it comes to my baby grandsons.

People also use a variety of nuts in the slot to obtain a treaded hole. I found that the inexpensive two and three hole "economy T-nuts" work better than the other more expensive choices. With two hole economy nuts I put a bolt in one of the holes to give me a "handle" to move the nut in the slot to where I want it. Once located a set screw in the second threaded hole locks nut in place. Makes adding a threaded hole in vertical extrusions much easier than single nuts. The three hole economy nut is used where I need two bolts to keep the attached part from rotating. Set screw in center hole. Disadvantage is you must have access to extrusion end to insert the nuts.

Agreed on all counts. Except that many of the nuts - roll-ins or rotating - can be purchased in bulk pretty affordably - so I use all three types, depending on the application. Flat are least convenient and most solid/secure. Rotating are almost as solid but hard to nail-down location if it's a blind install. Roll-ins with springs are best for blind installs. Then there's roll-ins with arms... and more. I've used as many as I can find just to see how they all work.

You are correct, I don't have the ability to hold that kind of tolerance and like the gussets much better. It depends on the project goals of course.

To the point of the above, I'll be using gussets as well.

 

The "Pilot" is the Key to the Counterbore cutting well. It constrains counterbore in the radial axis, normally counterbore's are used add recess's for screw heads (sit flush with surface) or to spot face surfaces (on casting) for good bearing of the underside of screw heads. A .001-.003 clearance of hole to pilot works well, more clearance (.005-.010) will also work , the difference will be the finished diameter (oversize) and taper of the counterbore. for most uses (screw heads) this is not a issue. For the anchor connectors I would assume that a minimum taper and on size hole would be desirable.

If I was to do this on a drill press I would use a Split Point drill (self centering properties - improved hole location)and not a Chisel point drill which is typical of hardware store drills. Home Depot sells Split Point drill's. the difference is the grind on the end of the drill. drill hole .010-.015 undersize, follow with a Reamer .001 oversize of the pilot diameter. Run the Counterbore at a low speed to reduce chatter (vibration) use WD-40 as a cutting lubricant (works well on aluminum) keeps the chips from gumming up the works, better hole accuracy and finish, with drill press off, insert pilot into hole, add a clamp (C-clamp?) to hold the 80/20 to the drill press again to reduce chatter (vibration)

Split Point drill are also good when drill harder material, Regular (chisel point) drills work harden the material (make the material even harder) Stainless steel in notorious for work hardening when drilling. Regular (chisel point) drills are good for drilling wood.

I am a machinist with access to a Bridgeport manual mill also a CNC mill, so I have no need to do this on a drill press. But I am confident that if the above is followed, satisfactory hole geometry for the "anchor connectors" is possible on a drill press.

Regarding using End mills in a drill press (DONT) Milling machine Spindles are constructed much more accurately and stiffer (preloaded bearing) than drill press spindles, Drills and Countersinks with their tapered points have a dampening and stabilizing effect on the tool also self centering effect when drilling into solid surface's. ever notice how a drill chatters when opening up an existing hole to a larger diameter.
End mill's with a square end will exercise all the play in the drill press spindle when drilling into solid material, combined with the inherent lack of stiffness in most drill presses and you got a hot mess.

While it may seem like a lot of work it goes quick, if one was doing thousands of holes I wouldn't recommend this method, the average DIY van builder is maybe going to need maybe 50 anchor connectors? at most.

Once the pilot hole is drilled the Reamer and Counterbore will follow the existing hole (no choice) A drill fixture (with a hardened drill bushing) to locate the pilot hole would make it almost foolproof.

 

The "Pilot" is the Key to the Counterbore cutting well.
...

Wow. I re-read that three times already. Going to soak in that information. Thank you for the expert input - I had no idea on pretty much any of that other than the, "yup, it chatters," that I've experienced so often with my crappy tools and techniques.


It turns out I had purchased a batch of anchor fasteners on eBay a while ago... and then a batch of them from McMaster. And the McMaster ones are simply wrong. So... it looks like one of the two-step bits I got might work. I will try it soon.

And it looks like all the end-fasteners from McMaster are also wrong - or, at least, wrong bolt included - so I'll have to replace those as well.


Hope to test the anchors later today... or tomorrow... good luck to me! 🤣

 

I did use the end connectors where I did not want angles to show.

I used two different methods for mounting 1/4" panels on series 15. Both inset panel 1/8" to expose the extrusion corner radius. Looks much better than flush.

1. Simple wood block where panel did not need to be removable.

For removable panels I fabricated a custom angle. Need chop saw and band saw for this one.

 

I had bought a pilot counterbore last week after seeing a comment on a different forum.. today I had a chance to try it.

This is the tool I have been waiting for.

The downside is two steps, and having the extra hole. The smallest pilot I could find was 1/4. I used one size larger drill bit.

Works great. No chatter, round hole.

Extra points for "safety sandals".

Video of the first cut, including shedding the protective wax:

https://photos.app.goo.gl/bYMj3hhaqNv6dqBw5

 

So, I have used the plastic jig and a regular drill bit in my drill press. Utter failure from wobling. Of course the jig while cheap to print was good for one time only. The jig might last longer if the bit would work properly.

What exact pilot counter bore bit, where to purchase and is this 80/20 15 series or 10 series. Can't tell from the pics. Thanks!

BTW, sandals are the only way to drill when it's 95+ F.

 

Excellent footwear choice when making metal chips and shavings!

 

 

Also, I used a drill press with a drill press vice bolted down to the press. Big heavy bolts. Get the right speed,Lube and an end mill worked great for 80/20 fastener they requires and end mill. Don’t recall the name of the fastener.

 

Took me 2 minutes to find them on Amazon

 

Should have taken you much less than two minutes. Unfortunately, they're not all quite what they say they are. You've been here almost a year and you choose this to be your first post? 😏

On the outside chance that you weren't just intentionally being a troll... if you think you found something useful, a link would be helpful.

 

For my series 10 build, I used a 9/16" 4-flute end mill on my budget Wen drill press to cut anchor holes. I started with a 2-flute which didn't work too well. The hole comes out a tad wider than optimum but the results were good.

 

I have the same drill press. And I did get some good results from a proper end-mill, but I'd call it hit-and miss. The pieces of 1030 I'd be working on where the most frustrating where I'd get two great holes and the third would just go completely bonkers. The pilot counterbores are a lot more reliable.

I have seen a lot of advice to use lower RPMs, though. 1500 seems high?