[4]

Hold Down Clamp

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#1
I decided I need a hold down to fit in the T-slots of my drill press table (if you have seen my faceplate in my Clausing thread you know what I mean.) I have been fascinated by the construction of Kant Twist clamps. They use stamped out sheets and spacers to create a rigid 3-D structure. I got thinking..."ya know I have this old stainless steel grill...and I have some home made 85,5,5,5 brass....









Robert
 
Last edited:

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#2







Probably overly complex for a hold down clamp. Looks cool and works great!
Robert
 
Last edited:

hman

Active User
H-M Platinum Supporter ($50)
Joined
Feb 17, 2013
Messages
1,729
Likes
1,354
#3

T Bredehoft

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 27, 2014
Messages
2,640
Likes
2,036
#4
Depending on the cutting load, I'd reverse the two ends, but the short end holding the part. MOre clamping pressure that way.

Great job making it, bye the way.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#5
It is easily spun around if you want the larger feet on the work and more force. Also you can drill between the arms if necessary.
Robert
 

Janderso

H-M Supporter - Sustaining Member
H-M Platinum Supporter ($50)
Joined
Mar 26, 2018
Messages
666
Likes
386
#6
Great idea and good work.
I may just have to make a few of these.
 

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#7
Hi Robert, Guys,

Very spiffy ! I like the large clamp head.
I made some clamps quite similar some time ago, specifically for securing some plate to the mill bed.
Here is a picture of mine:
15-07-2017-015.JPG
Nowhere as pretty as yours.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#8
Baron- I really like that one also. Heavier duty. Maybe my next one!
Robert
 

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#9
Hi Rwm, Guys,

Somewhere I have the plans/notes for them if you want them.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#10
Thank you but I will just "wing it" on Fusion. Sigh, I only I had a CNC laser cutter...
BTW- the cost of this was $0. Stainless from an old grill and brass from salvaged copper pipe.
Robert
 

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#11
Hi Robert,

Almost all of the machining on those was done on the lathe faceplate.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#12
I am making another but... where the heck can I buy Red Brass round stock???? Everyone has C360 but no C260 aka red brass aka 85three5. Any ideas other than burning 10 lbs of propane?
Robert
 

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#13
Hi Robert, Guys,

Those rollers that I used were bits of copper busbar from an old earth rod. From the days when they were copper and not just plated steel.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#14
I have discovered that 85 three 5 is commonly know as 836 bronze. Unfortunately, I cannot find any in the 1" range on ebay or from my usual suppliers. Anyone have some by chance?
Robert
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#15
So....I decided I would cast my own brass for the next piece.
I started with some scrap and some red brass that had too much porosity for machining. I weighed my material and decided I needed about 3g of Phosphor Cu to degas my 11 lb melt:



Added Phospho Copper after skimming:



Stirred and poured:



Shakeout:



This seems to have removed most of the porosity and it machines pretty well! Very satisfactory!



Thanks for watching.
Robert

 
Last edited:

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#16
Hi Robert,

That material looks very nice and seems to have machined well.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#17
Yes! I love the color. I am going to make more I think. I turned it between centers and had to cut off about .080 to get thru the rough outer surface. I still have slightly more than 1" diameter to work with. I am on the hunt for scrap copper.
Robert
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#18
Machines beautifully with no porosity!



Robert
 

Ken from ontario

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Dec 26, 2016
Messages
866
Likes
621
#20
rwm, Great looking hold-down clamp, I'll have to make one like it for myself. well maybe not as nicely finished as yours but just as functional.

Somewhere I have the plans/notes for them if you want them.
I would like to see the plan for your clamp if you you don't mind posting it or at least post a picture of the opposite side of the picture in your post, I'd like to see whether you used E clamps to fasten the bolts or just screwed in.
Thank you both for the inspiration.
 

Firstram

Registered
Registered
Joined
May 26, 2018
Messages
51
Likes
62
#21
That's a nice foundry setup! Show us more of your casting work if you don't mind.
 

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#22
rwm, Great looking hold-down clamp, I'll have to make one like it for myself. well maybe not as nicely finished as yours but just as functional.


I would like to see the plan for your clamp if you you don't mind posting it or at least post a picture of the opposite side of the picture in your post, I'd like to see whether you used E clamps to fasten the bolts or just screwed in.
Thank you both for the inspiration.
Hi Ken,

That bush at the top is just drilled through and has a nut and washer there, it just pulls against the "T" nut in the conventional way.

Toggle_Clamp_amended.jpeg 15-07-2017-009.JPG

15-07-2017-016.JPG

Does these pictures help.
Here is a couple of pictures of how they were made.
29-06-2017-014.JPG 29-06-2017-024.JPG

Notice that they were machined as pairs. I made a second jig to turn the inside radius, then the corners were filed round.
 

Ken from ontario

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Dec 26, 2016
Messages
866
Likes
621
#23
Thank you BronJ for the pics.they help a lot.
rwm, nice setup you have for casting your own, the brass came out looking great, very interesting.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#24
Thank you all.
I used 10-32 screws on both sides of the plates.
I will post some more pics here when I make some more turning stock. I have 23 lbs of scrap copper coming. I can start a thread of various castings in the casting section if there is interest?
Robert
 

mickri

Registered
Registered
Joined
Oct 31, 2016
Messages
281
Likes
153
#25
How thick do the side pieces have to be? I have a large sheet of .050 aluminum plate. Would that be thick enough? I could double or triple it.

Also does anybody ever drill and tap holes in the top of their mill vises for clamps?
 
Last edited:

BaronJ

Registered
Registered
Joined
Aug 7, 2018
Messages
334
Likes
181
#26
Hi Mick,

I made the side plates of mine out of 5 mm mild steel plate, but amended the drawing to show 3 mm, which is plenty thick enough.

I've just had a look at the pictures I posted, they do look quite fuzzy on here. I wonder if it is something to do with the resizing software on the forum.
I don't use bitmap pictures at all, normally JPG, PNG or GIF.

To answer your last question, NO, My vise is fully hardened all over. It does have two tapped holes for end stops though.
 

T Bredehoft

Active User
H-M Supporter - Gold Member ($25)
Joined
Dec 27, 2014
Messages
2,640
Likes
2,036
#27
does anybody ever drill and tap holes in the top of their mill vises
You could drill and tap holes in the 'soft jaws', that attach to the vice. I have 10-32 holes in the ends for installing part stops.
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#28
How thick do the side pieces have to be? I have a large sheet of .050 aluminum plate. Would that be thick enough? I could double or triple it.

Also does anybody ever drill and tap holes in the top of their mill vises for clamps?
I would not use aluminum.
Robert
 

mickri

Registered
Registered
Joined
Oct 31, 2016
Messages
281
Likes
153
#29
Why not aluminum?
 

rwm

Active User
H-M Supporter - Gold Member ($25)
Joined
Mar 25, 2013
Messages
1,371
Likes
1,559
#30
.050 aluminum is too soft and weak to handle strong clamping forces. Double or triple thickness may work if that is all you have. I was worried about .065 stainless.
Robert
 
[6]
[5] [7]
Top