Eritex Inc's HRD 3.1 setup and tip thread

[oldhippie]

Is anyone using the servo mount? My drive shaft hits before full compression/droop. I'm really not happy with the one hole mount either. Made a mount out of 1/8 alum but it bends. I'm cutting out a real mount but it is a pain. Of course all digs need some kind of mount but I'd think the one designed for the dig would at least come close to working. I'm also not to happy about the short lock-up hex. ya really have to set the epa right to get it to engage without over stressing the servo and the long freewheel area allows alot of rollback on a controlled climb. But overall I like it. We'll see how the alum hexs hold up.

[Narly1]

Originally Posted by oldhippie

Is anyone using the servo mount? My drive shaft hits before full compression/droop. I'm really not happy with the one hole mount either. Made a mount out of 1/8 alum but it bends. I'm cutting out a real mount but it is a pain. Of course all digs need some kind of mount but I'd think the one designed for the dig would at least come close to working. I'm also not to happy about the short lock-up hex. ya really have to set the epa right to get it to engage without over stressing the servo and the long freewheel area allows alot of rollback on a controlled climb.

The short hex for rear wheel lock mode is a consequence of the design objective of making the dig as compact (in other words as short) as possible. Plus you don't need a hex the full width of the sliding collar in rear wheel lock mode. After all, you are only holding the rear wheels and axles, not applying power to them.

The "long" freewheel area (or length) is a consequence of the minimum sliding collar width necessary to ensure a robust engagement in both the 4WD and rear wheel lock mode.

I suppose you could look at as fast a servo as possible to minimize the transit time......maybe even a "throttle return spring" type arrangement to help speed the transition up (at the expense of making your servo work against the spring force in 4WD and rear freewheel modes).

Also if you are on a really steep section of the course perhaps running in rear freewheel mode would be a better decision. If that is the case then the transition time between rear freewheel and rear wheel lock modes is greatly reduced......

Narly1

[kwkride]

Originally Posted by oldhippie

Is anyone using the servo mount? My drive shaft hits before full compression/droop.

Have your tried rotating the mount to gain clearance? This is the advantage to a one hole mount.

Do you have a picture of your setup?

[oldhippie]

Originally Posted by kwkride

Have your tried rotating the mount to gain clearance? This is the advantage to a one hole mount.

Do you have a picture of your setup?

Yes, I have moved it all sorts of ways. Seems to me the one slot mount is a pretty poor way to mount anything (handy for taking apart/falling off).

I admit to being an idiot and haven't figured out how to post photos. But it is a stock ax10 Chassis/trans/axles/shock setup 4 linked with bent links and pede shaft (the mpi shaft is worse).

[oldhippie]

Originally Posted by Narly1

The short hex for rear wheel lock mode is a consequence of the design objective of making the dig as compact (in other words as short) as possible. Plus you don't need a hex the full width of the sliding collar in rear wheel lock mode. After all, you are only holding the rear wheels and axles, not applying power to them.

The "long" freewheel area (or length) is a consequence of the minimum sliding collar width necessary to ensure a robust engagement in both the 4WD and rear wheel lock mode.

I'm not a designer or an engineer. I just report what I see. What I see is some space between the output hex and lock hex that could/should have been lock hex. If it was hex the freewheel throw would be shorter. Also there is no robust engagement of the rear wheel lock mode with that small hex area no matter how wide the sliding hex is. I do think it is a kool design and works great.

I suppose you could look at as fast a servo as possible to minimize the transit time......maybe even a "throttle return spring" type arrangement to help speed the transition up (at the expense of making your servo work against the spring force in 4WD and rear freewheel modes).

I am looking at a high speed servo but I don't think it will really make much difference. It really isn't that big a deal. I was just bugging me on on one climb but I could be my sad driving skills.


Also if you are on a really steep section of the course perhaps running in rear freewheel mode would be a better decision. If that is the case then the transition time between rear freewheel and rear wheel lock modes is greatly reduced......

Narly1

The problem with freewheel on a steep slop is only two tires holding the rocks and just sliding down. But I also admit to being a shi&&y driver.

[kwkride]

Originally Posted by oldhippie

Yes, I have moved it all sorts of ways. Seems to me the one slot mount is a pretty poor way to mount anything (handy for taking apart/falling off).

I admit to being an idiot and haven't figured out how to post photos. But it is a stock ax10 Chassis/trans/axles/shock setup 4 linked with bent links and pede shaft (the mpi shaft is worse).

OK, well here are a couple of pics of my setup, I hope this helps.



This one is from the side with the suspension fully compressed.



There is still clearance between the driveshaft and the servo mount.

[oldhippie]

I guess I just have too much up travel. I'm making a mount that angles the rear of the servo up, and the front alittle lower. No big deal. The dig worked pretty well at the comp tonight, even with my floppy mount. Only didn't engage lock a couple times (could be my finger or the mount). I'm using an old traxxas 2070 servo and it has plenty of power.
BTW that's a very kool looking chassis.

[kwkride]

I'm glad that it worked for you, I've been really happy with mine.

Originally Posted by oldhippie

BTW that's a very kool looking chassis.

Thanks, it's another Eritex creation.

[LIKES2CRAWL]

Where's the breaking video or did I miss that somewhere?

[Eritex Inc.]

Originally Posted by LIKES2CRAWL

Where's the breaking video or did I miss that somewhere?

I need to edit it down to less then 5 minutes. I will get on it this weekend.

[The Cracker]

its been a while since i have posted pics but i hope these work. I made an "L" bracket to mount the servo mount. i also drilled a hole in the servo mount so that it had two secure screws. hope it helps somone else out. it works well for my truck, weight is low, it clears everything by tons of room, like 1mm :-)

[oldhippie]

Looks good!

[latentimage74]

Originally Posted by kwkride

OK, well here are a couple of pics of my setup, I hope this helps.



This one is from the side with the suspension fully compressed.



There is still clearance between the driveshaft and the servo mount.

did you use a mini servo? if not what chassis is that?

[Eritex Inc.]

Originally Posted by latentimage74

did you use a mini servo? if not what chassis is that?

Actually, he is running a 225mg with his dig and the chassis he is running is one I cut for him

[latentimage74]

Originally Posted by Eritex Inc.

Actually, he is running a 225mg with his dig and the chassis he is running is one I cut for him

what's the width on that chassis?

[Eritex Inc.]

Originally Posted by latentimage74

what's the width on that chassis?

3.125" if I remember correctly.

[latentimage74]

Originally Posted by Eritex Inc.

3.125" if I remember correctly.

it looks good but a full size servo is going to be a bit tight in the swx

[Eritex Inc.]

Originally Posted by latentimage74

it looks good but a full size servo is going to be a bit tight in the swx

It all depend on the servo mounts you use. Also, you can shim the servo over away fro the chassis without adversely effecting the function of the dig.

[latentimage74]

Originally Posted by Eritex Inc.

It all depend on the servo mounts you use. Also, you can shim the servo over away fro the chassis without adversely effecting the function of the dig.

good info. ill see what i can come up with. what's the minimum oz of torque you recommend for a servo? it seems pretty smooth, like it does not take much.

[Eritex Inc.]

Originally Posted by latentimage74

good info. ill see what i can come up with. what's the minimum oz of torque you recommend for a servo? it seems pretty smooth, like it does not take much.

I run a JR ST47 on mine that has about 50 ounces of torque at 6v. 50 is about the minimum I would suggest.