T-slot nut for Hammer K3

[Wakahisa Shinta]

I want to make my own accessories for a Hammer K3 slider. One of them is hold-down clamp to secure work piece to the sliding table. I have no luck finding the proper T-slot nut for the T-slot in the sliding table. I've looked at ebay and mcmaster, but couldn't find any that fit the T-slot size. The ones available aren't exactly sized to the T-slot. The picture below is the maximum dimensions that a nut will fit in the T-slot (note the rounded bottom corners). Measurement using a caliper. Anyone knows of a better source, aside from Felder?

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[Ryan Mooney]

For most uses a chunk of flat bar stock sized to fit the inside of the slot minus the top part works just dandy. That's what I used when I cross threaded the one that came with the excentric clamp. Basically just took a piece of 1"x3/16" cold rolled stock and cut it to dimension with a hacksaw and cleaned it up with a file. Worked a charm.

[ian maybury]

Hi W. They don't seem to be standard. I make my own from a high strength grade of cotton reinforced phenolic material - the advantages being that it machines nicely on a router table, doesn't risk (as might a steel one) grinding through the anodising on the slider and tends to encourage care in tightening/prevent overtightening and damage to the T slot.

I have a Felder clamp which i use with the F3 shaper for tighter hold down, but it makes me nervous as it's a very heavily built bit of kit with steel surfaces which if not used carefully could well damage the T slot.

I also make my own hold down clamps from F clamps - if doing so it's probably advisable to make the top block a little wider than mine to leave a thicker wall each side of the threaded mounting. I've had no problem, but do take care to lock down both of the socket head screws before tightening the clamp, and to not over tighten it.

6061 T6 aluminium would also be an option, and a bit stronger - but probably requires a mill (which as it happens i now have) and would be best anodised afterwards which would up the cost...

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[Rod Sheridan]

I want to make my own accessories for a Hammer K3 slider. One of them is hold-down clamp to secure work piece to the sliding table. I have no luck finding the proper T-slot nut for the T-slot in the sliding table. I've looked at ebay and mcmaster, but couldn't find any that fit the T-slot size. The ones available aren't exactly sized to the T-slot. The picture below is the maximum dimensions that a nut will fit in the T-slot (note the rounded bottom corners). Measurement using a caliper. Anyone knows of a better source, aside from Felder?

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I make mine out of hardwood with a "T" nut in it.................Rod.

[Mike Wilkins]

Grizzly has a selection of T-nuts in the metal working section of their catalog. I purchased several after purchasing the Laguna Pro 6' sliding saw to make jigs and hold-downs for the sliding table. Just measure the dimensions of the slots, both the bottom of the groove and the top of the groove, and order the ones that fit that dimension. Make note of the thread size and purchase some from the local hardware outlet.

[Wakahisa Shinta]

Well, I used the T-nut/bar made after looking at the examples post here and Rod's description to quickly make a hold down clamp for cutting wedges today. The T nut/bar is made out of white oak. The platform base for the toggle clamp is poplar, another scrap piece. It's quick and dirty, but gets the job done; keeping my fingers clear of the blade. I think I will make another platform base out of oak later. As it is now, the whole contraption has some lateral movement and the clamp can turn 90 degree. The oak T nut/bar slides effortlessly in the T track without any lubricant. There is plenty of rigidity once the bolts are torqued tight and less risk of damaging the aluminum sliding table.

Thanks for all your help! I have another 4' of white oak T bar in reserve! :D

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[John Lankers]

I made these clamps form left over hard maple, the advantage is they reach over the crosscut fence and don't shift when clamping down like the Destaco clamps sometimes tend to do, the disadvantage is they are e bit slow to operate.
I tapped a 1/2" thread directly through the clamp and into 3/4" BB ply I shaped to fit in the miter slot. I used the bathroom scale to check the clamping pressure and at 250 lbs that is much more than I need. The clamps are 2 years old and if the threads in the BB t-bars ever wear out I'll make new ones, I just don't like the idea of using steel in aluminum tracks. Phenolic would be perfect, but it only takes me 15 minutes to make new ones let's say from beech. I can post some more detailed pics if interested.

[Wakahisa Shinta]

John, those rubber feet of your clamps. Are they table leg rubber tips? I like how you painted the clamps. I will most likely copy your design if you don't mind.

[John Lankers]

Thanks
The feet are in fact chair/table feet protectors from HD, they fit snug over the round head of a 1/2" carriage bolt. I'll see if I can a few detailed pics.

[Keith Outten]

There are a number of hard plastics that might be a better choice rather than using maple or white oak for this application. You can use epoxy to join the T-nut to the plastic.
I have used Corian to make similar clamp blocks in the past, it won't damage soft aluminum its easy to machine and it will never compress as wood will do over time.
.

[John Lankers]

There are a number of hard plastics that might be a better choice rather than using maple or white oak for this application. You can use epoxy to join the T-nut to the plastic.
I have used Corian to make similar clamp blocks in the past, it won't damage soft aluminum its easy to machine and it will never compress as wood will do over time.
.

I agree, but deciding between scrap wood and materials that need to be ordered was easy for me and I'm really happy how wooden threads wear.

[Bill Adamsen]

Wood and plastics might be great alternatives. If you are set on using steel ... I would send that drawing to a machine shop and ask what they'd quote to fabricate. It could be as simple as two strokes of the Bridgeport on a piece of 1" by 3/4" (25.40mm X 19.05mm) mild steel. If the fit is tight, a few seconds on a disc or belt sander should fix it. I'm assuming you can drill and tap the hole yourself? Machining that would be about $10 each in these parts. Try CT Saw ... this is right up their alley! A few weeks ago I had them machine down two of the Felder blocks (anout 1.5mm off bottom) to fit my Knapp shaper track ... $20.

The Felder factory item is I believe
http://us.feldershop.com/en-US/en-US/en-US/en-US/Sawing/Accessories/Spann-und-Klemm-einrichtungen/Clamp-set-for-Eccentric-clamp.html
or
http://us.feldershop.com/en-US/en-US/en-US/en-US/Sawing/Accessories/Sliding-table-accessories/Mounting-set-M10.html

[Kevin Nathanson]

90510A216 McMaster Carr; they have many nuts that will work. I use them with my Felder Slider.

K

[Wakahisa Shinta]

Just as John said, I wanted to make a hold down jig real quick to solve a problem, cutting small wedges to fit into wedged tennons for the saw horses I am building. I had made the white oak T bar recently and wanted to test it out. It works well I'd say.

Keith and Bill, your suggestions are exactly the reasons why I am considering replacing my Ryoby BT DP with a small mill. I can buy various plastic cut offs from a local plastic fabricator and make these sort of jig fixtures any time I want. Small aluminum stock is also available at a local hardware store.

Keith, any other recommendations for the hard plastic, aside from Corian?

[Keith Outten]

Wakahisa,

I'm not very knowledgeable about plastics but I have plenty of Corian scraps from sign projects so I use it almost daily to make shop jigs, templates, etc. I know that you can order just about any type of plastic material from McMaster Carr but I would suggest that you contact any of your local cabinet shops or counter top shops in your area as they would most likely be happy to give you a pice of scrap that would make dozens of T-nuts. If you can't find any let me know.

Your right about the mill, I made custom T-nuts for my Jet mini lathe several years ago to resolve a problem with the tailstock that wouldn't lock properly. I made mine from mild steel and drilled and tapped the hole with metric thread so it was a direct replacement for the stock washer that Jet provided. I use my Grizzly mill/drill so much that I ordered a power feed for the table several years ago that makes it much more enjoyable to use.

[Wakahisa Shinta]

Keith, thank you. I will wander over to the local plastic fabricator soon.

I went to the local Woodcraft today and found this (http://www.woodcraft.com/product/145969/woodriver-quick-set-drill-press-hold-down.aspx), went home, and made this.

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The clamp's reach is a bit short as you can see in the picture above. The rubber foot will need to be shaved off on one side to clear the fence. The bottom of the steel rod has a M10-1.5 thread, so I tapped the same thread size into both the T-nut and wood spacer (white oak). The metal washer, which is one of two washers that come with the clamp, is needed in order for the bottom threaded portion of the steel rod to clear the bottom of the aluminum T-slot (Hammer K3), given my wood thickness. The wood spacer above the table is also tapped M10-1.5. I thought this would provide more holding power.

Once moved to the other side of the fence, it works quite well. There is plenty of clamping power. It might not be as elegant as the Felder hold down clamp, but it is about 15 times less costly. For one Jackson and some time playing (priceless) in the shop, I am satisfied. I will make one more to make a set.

[Bill Adamsen]

Today I too made up some t-nuts from scrap mild steel drilling and tapping. It allowed fitting a backing block (prevent tenon blowout) and measuring bracket to my auxiliary fence to allow quickly setting the rail face length cutting tenons. Total effort 20 minutes and cost $0! Some may object to the primitive lock handle but the functionality is just fine. I'll probably buy a kipp lever for the jig in the future.

[Bill Adamsen]

The el-cheapo carriage bolt version worked but couldn't pass under the clamp, so this morning - against my principles - I made a lever to make the system more functional. It still cost zero dollars unless you count the cost of the scrap steel, grinding disc, time, and wear and tear on other fabrication tools.

[Wakahisa Shinta]

Nice lever! BTW, Bill, your backing block is being used on a shaper isn't it? I racked my brain trying to figure out how you are using it on a slider and came up with nothing.

Part of the fun in the shop, for me, is tinkering to make jigs and stuffs like these to improve the machines' functionality to my specific needs. I plan to keep adding to this thread to make it a collection of shop-made accessories for a slider (Hammer K3 in my case). Hopefully, more people will chime in to contribute ideas. We will most likely learn and benefit.

[Bill Adamsen]

Bill, your backing block is being used on a shaper isn't it? I racked my brain trying to figure out how you are using it on a slider and came up with nothing.

It is a combo machine so the slider functions as a tenon table (slider) on the shaper as well as the slider for the saw. The hold-downs can be used for both tools as well ... but end up being used primarily for the shaper. I have referenced t-nuts (affix the hold-down clamp to the sliding table) and then also retaining track nuts, which affixes a wooden "backing block" to the sliding tenon table (to prevent blowout where the shaper cutter exits the tenon). That backing block is affixed to the sliding table's fence. The benefit of that arrangement is that with that tenon "indexer" (that the other retaining track nut is attached to) I can quickly index tenons on the sliding fence, and easily replicate length on the rails for a face frame or door. It beats trying to mark and then sight by hand, and then get the same measurement on the next tenon.

[John Lankers]

Part of the fun in the shop, for me, is tinkering to make jigs and stuffs like these to improve the machines' functionality to my specific needs. I plan to keep adding to this thread to make it a collection of shop-made accessories for a slider (Hammer K3 in my case). Hopefully, more people will chime in to contribute ideas. We will most likely learn and benefit.[/QUOTE]



Wakahisa, here is a link to a youtube video, it is not exactly what you're looking for but check out the wooden cam clamps. He has mounted them horizontally but a person could build them to apply pressure vertically also.
https://www.youtube.com/watch?v=jAS04mlmlS0

[Peter Lloyd]

Has anyone tried the DEWALT DWS5026 TrackSaw Track Clamps by adapting the base.

[Derek Cohen]

I think that all are over-thinking the connector within the K3 slot. All that is needed is a square of aluminium or steel, drilled and tapped for the thread of your choice. Special shapes to fit in the slot, per se, are unnecessary.

Below is an example of a flat section of aluminium. This one began life as a connection for a t-track of some type, but I simply tapped out the thread and it is wide enough to hold securely ...

https://i.postimg.cc/Bn8gSWWY/7a.jpg

That is the K3 track, with the end of a F & F jig ...

https://i.postimg.cc/5t4SDHGD/1.jpg

The attachment on the right is similar. This is into the track on the side ..

https://i.postimg.cc/QNbSSkkb/9a.jpg

This track is helpful in attaching the sliding mitre jig I built (copying the one by Felder) ...

https://i.postimg.cc/7LMYwLwn/1a.jpg

https://i.postimg.cc/yxWVmX9L/5a.jpg

Regards from Perth

Derek

[Mike Wilkins]

Get the measurements for the T-slots from your machine and go to the Grizzly catalog in the metal-working section. Get some T-nuts that are slightly under the slot size on your machine, some local bolts from the local hardware store and you are good to go. I did that for my Laguna sliding table saw and it has worked well for jigs. I used socket head bolts (for hex wrenches) and washers to hold things down.