T Slot fillers

**olderdan** · Dec 1, 2016, 01:48 PM

Tired of cleaning out those T slots, prevention being better than cure why not fill them up with inserts.
I made mine for my boring table from pieces of oak flooring off cuts to an easy fit and soaked them in thin oil before use.
Made them just below the top surface so they can stay put until you need the slot for something, I could claim its saved me hours but in truth I have merely got rid of a minor irritant in having to running brushes though them.
This is only practical for short slots as in a lathe when a lot of set up changes are done and there is no room for cover boards.
Regards
Olderdan

**Toolmaker51** · Dec 2, 2016, 06:46 AM

Some Okuma and MoriSeiki lathes I've seen have these in the slots for a back toolpost. A good idea...but if water based coolant is used, they have to be removed periodically and cleaned or replaced. The wood holds moisture long enough to rust in contact with the cast iron. And petrol based oils rot wood.

**olderdan** · Dec 2, 2016, 01:15 PM

Good points about the use of wood, it did not occur to me as I dont have a coolant supply (after years of coming home reeking of the stuff I now work dry or brush applied).
Regards
Olderdan

**C-Bag** · Dec 2, 2016, 02:09 PM

Funny, I was thinking what a great idea this is but I don't have any suitable wood, but I've got lots of UHMW!

I don't used a flood system on my puny hobby lathe and just brush on too.

So, I'm afraid to ask what's wrong with UHMW TM51?

**Frank S** · Dec 2, 2016, 07:12 PM

I used to own an older Dutch made Gromatic lathe with T slots in the carriage even though teh lathe at the time was more than 40 years old it still had 3 of the 4 factory ruber slot fillers in it over the years long before I got it the lathe had been repainted numerous times. I thought for a while that it had only the 1 "T" slot until 1 day I was scraping it down for a refurbishment and repaint when I discovered the rubber fillers. Once removed being so old and hardened they were impossible to return to the slots so I just left them out.
I would think that UHMW would be about as water or solvent neutral as just about any material you could use. As for wood fillers something made out of Maple black walnut or mahogany or possibly ash soaked in tongue oil and dried might do the trick. But Teak might the a better choice all would look really nice as well

**Toolmaker51** · Dec 2, 2016, 10:36 PM

UHMW, or most woods sealed with preservative should be good. I can't imagine UHMW soaking up anything present around machine tools. There are too many rubber-like materials that react to coolants.
I'm thinking a shallow Vee cut to sit less than flush AND not touching bottom would be a good combo.
This works for milling machines too, of course. There are commercial 'seals' made of aluminum with drain holes along the length. I suppose, personally not thought much about tee-slots until present position...most work gets flood coolant on the lathe, and spray-mist on the mill. They have aluminum fillers with drain holes. Top is about 1/16" diameter, no countersink, but back-drilled larger, 1/8" mol. The lathe still needs one or another type of deflectors for the chuck.